Planet Release Engineering

February 18, 2021

Armen Zambrano G. (@armenzg)

Making pip installations faster with wheel

I recently noticed the following message in Sentry’s pip installation step:

Using legacy ‘setup.py install’ for openapi-core, since package ‘wheel’ is not installed.

Upon some investigation, I noticed that the package wheel was not being installed. After making some changes, I can now guarantee that our development environment installs it by default and it’s given us about 40–50% speed gain.

<figcaption>Timings from before and after installing wheel</figcaption>

The screenshot above shows the steps from two different Github workflows; it installs Sentry’s Python packages inside of a fresh virtualenv and the pip cache is available.

If you see a message saying that wheelpackage is not installed, make sure to attend to it!

February 18, 2021 04:24 PM

February 03, 2021

Armen Zambrano G. (@armenzg)

Making Big Sur and pyenv play nicely

Soon after Big Sur came out, I received my new work laptop. I decided to upgrade to it. Unfortunately, I quickly discovered that the Python set up needed for Sentry required some changes. Since it took me a bit of time to figure it out I decided to document it for anyone trying to solve the same problem.

If you are curious about all that I went through and see references to upstream issues you can visit this issue. It’s a bit raw. Most important notes are in the first comment.

On Big Sur, if you try to install older versions of Python you will need to tell pyenv to patch the code. For instance, you can install Python 3.8.7 the typical way ( pyenv install 3.8.7 ), however, if you try to install 3.8.0, or earlier, you will have to patch the code before building Python.

pyenv install --patch 3.6.10 < \
<(curl -sSL https://github.com/python/cpython/commit/8ea6353.patch\?full_index\=1)

If your pyenv version is lesser than 1.2.22 you will also need to specify LDFLAGS. You can read more about it here.

LDFLAGS="-L$(xcrun --show-sdk-path)/usr/lib ${LDFLAGS}" \
pyenv install --patch 3.6.10 < \
<(curl -sSL https://github.com/python/cpython/commit/8ea6353.patch\?full_index\=1)

It seems very simple, however, it took me a lot of work to figure it out. I hope I saved you some time!

February 03, 2021 10:09 PM

January 19, 2021

Armen Zambrano G. (@armenzg)

Joining Sentry

I’m happy to announce that at the end of 2020 I joined Sentry.io as their second Developer Productivity engineer \o/

<figcaption>Screenshot from Sentry.io landing page</figcaption>

I’m excited to say that it’s been a great fit and that I can make use of most of the knowledge I’ve gained in the last few years. I like the ambition of the company and that they like to make work fun.

So far, I have been able to help to migrate to Python 3, enabled engineers to bootstrap their Python installation on Big Sur, migrated some CI from Travis to Github actions amongst many other projects.

If you ship software, I highly recommend you trying Sentry as part of your arsenal of tools to track errors and app performance. I used Sentry for many years at Mozilla and it was of great help!

If you are interested in joining Sentry please visit the careers page.

January 19, 2021 05:14 PM

December 31, 2020

Armen Zambrano G. (@armenzg)

Farewell, Mozilla

The summer of 2020 marked the end of 12 years of working for Mozilla. My career with Mozilla began with an internship during the summer of 2008 when I worked from Building K in 1981 Landings Drive, Mountain View, CA.

<figcaption>One of the two buildings Mozilla used at Landings Drive</figcaption>

Writing this post is hard since Mozilla was such a great place to work at, not only for its altruistic mission, but mostly because of the fantastic people I met during my time there.

I’m eternally grateful to my Lord Jesus Christ, Who placed me in a workplace where I could grow so much, both as a person and as an engineer.

<figcaption>Photo taken during the Release Engineering work week (Pre-internship)</figcaption>

I can count dozens of Mozillians I’ve talked and laughed with over the years. I could try unsuccessfully to list each and every one, however I believe it’s better to simply say that I’ve enjoyed every moment with each one of you.

It’s been a long time since I’ve spoken with many of you and some of you I may never get the chance to talk with again. Nevertheless, if you ever see me somewhere online, please be sure to say hi. I would love to hear from you.

<figcaption>Presentation slide from London All Hands</figcaption>

Mozilla, thank you for the opportunity to help further your mission. I wish you success in 2021 and beyond.

December 31, 2020 07:16 PM

December 23, 2020

Chris Cooper (coop)

Wait and Hope

After 15 years, today is my final working day at Mozilla.

When people leave Mozilla, they frequently exercise their privilege to send one final email to the entire company saying goodbye. I’ve elected not to do that and am instead posting my thoughts here. Call it hubris, but there aren’t many people left at Mozilla who can appreciate what 15 years means. Most of my colleagues have already moved on.

2020 has been hard. Layoffs at Mozilla, and the threat of more layoffs, made this a particularly rough year. As a manager, putting on a brave face for others has left me emotionally spent at the end of every week. This is on top of the malaise associated with a decade of declining market share (and associated relevance) for Firefox.

As I reach the end of my tenure at Mozilla, inevitably I look back to try to figure out what I could have done differently to make Mozilla more successful. Did I miss a window of opportunity somewhere to help Firefox succeed? Might this year have been avoided, or its impact softened?

In broad strokes, sure, I could have worked longer or harder, pushed to get projects completed faster or to a higher standard. More specifically, if we had accelerated our transition from tinderbox to buildbot, or from buildbot to Taskcluster, could we have kept better pace with competitors? Maybe we could have recognized the scaling needs sooner and avoided migrating our entire continuous integration infrastructure twice?

The safe answer is that, yes, there are many things I could have done differently, but hindsight is also 20/20.

When I started this reminiscence, I felt like maybe my impact had decreased over time. It was tempting to think that my influence peaked back in 2005 when it was just 25 of us hacking together on Firefox under the Can Bridge in Ellis St.

But that’s absolutely not true.

Mozilla, at its core, is about people. The manifesto is an invitation. This is a long game; the changes that Mozilla wants to affect in the world aren’t best measured in quarterly earnings reports.

As a manager at Mozilla, I’ve had the opportunty to hire dozens of people. I’ve helped interns develop into kick-ass engineers. I’ve touched the careers of countless people and hopefully instilled some fundamental values along the way. Many of those people are no longer with Mozilla. This is a good thing, both for them and for Mozilla.

The world needs more Mozilla. In an industry largely bereft of introspection and in many cases lacking a moral compass, the Mozilla diaspora has some serious work to do. At the end of the day, if all I’ve done is helped spread Mozilla values out into the wider world, I’m happy with that legacy.

Mozilla has gone through big changes this year. I don’t know if those changes are enough for it to be successful, but I am hopeful. As part of the old guard, I am happy to step aside at this juncture to create space and opportunity for the new guard in my stead.

I’m starting a new adventure as a Senior Development Manager at Unity in January. I’ll be taking my Mozilla values with me.

December 23, 2020 05:56 PM

December 02, 2020

Chris Cooper (coop)

Taskcluster: CI for Engineers

Taskcluster logo - it's a big T

My team at Mozilla has been working towards something special for over two years.

When I joined the team, we felt that we had a pretty good internal product in Taskcluster, the task execution framework that supports Mozilla’s continuous integration (CI) and release processes. It served Mozilla’s CI needs well, and was scaling admirably compared to previous solutions.

But could it be more?

Would people outside of Mozilla benefit from Taskcluster, and could they deploy it? Perhaps more importantly, could we develop a community of users around Taskcluster that would be self-sustaining?

We were determined to find out.

We started by taking a hard look at the Taskcluster platform and found a few big impediments to wider adoption. First, we would need to reduce the setup complexity. We would also need to reduce the number of cloud accounts required to get started. At the time, Taskcluster required at least two separate cloud providers (AWS and Azure) and a Heroku account to launch.

Over the past year, we removed the need for Azure as a back-end data store and removed the need for Heroku for deployments. Now if you have a Kubernetes environment setup, you’re ready to install Taskcluster. You’ll still need AWS S3 access for artifact storage, but we’re working to make that configurable too.

While we were making all these changes behind the scenes, we were thinking about how we would actually try to garner more interest in Taskcluster outside of Mozilla. In true Mozilla fashion, we have always been developing Taskcluster in the open, but that doesn’t necessarily mean we were discoverable. How could we specifically target the kinds of users who would benefit the most from Taskcluster?

Out of the blue in August, a developer from a mobile game company contacted us to let us know that she had successfully deployed Taskcluster, and had a few suggestions for improvements, complete with patches.

Just like that, Taskcluster was in the wild.

Is Taskcluster right for you?

From talking with Ricky, the co-founder and principal programmer at Well Played Games who was the first to successfully deploy Taskcluster outside Mozilla, we learned a lot about the decision points that might lead someone to choose Taskcluster:

Taskcluster has given us more flexibility than any of the CI solutions we’ve used in the past. It is well engineered, letting us easily pick and choose the components we need, and quickly replace any that don’t suit our use cases. Its native support for Kubernetes meshes perfectly with our tech stack.<figcaption>Ricky Taylor, Co-Founder, Well Played Games</figcaption>

So, is Taskcluster right for you? The short answer is “maybe.”

If your build and test pipeline is straightforward, there are simpler solutions out there for you. If you only support one platform, there is probably a more targetted solution for your use case.

However, if your CI needs are more complex, Taskcluster may be exactly what you need.

Here are some examples of use cases where Taskcluster might make sense for you:

All of those are pretty good indications of CI complexity in our experience.

We’ve adopted “CI for Engineers” as the tagline for Taskcluster. Taskcluster will not solve your CI problems on it’s own, out-of-the-box, but a software engineer who understands your CI needs can make it do just about anything.

Better still, your software engineer doesn’t have to go it alone. We’re already building a community of Taskcluster users who can offer support to each other. Ricky from Well Played Games has already contributed new features that have been incorporated into Taskcluster and consulted on others.

If Taskcluster seems like a good fit for your CI needs, we encourage you to join other Taskcluster users and developers in Matrix or in Discourse.

Home page: https://taskcluster.net/
Documentation: https://docs.taskcluster.net/
Code: https://github.com/taskcluster/taskcluster/
Matrix: https://chat.mozilla.org/#/room/#taskcluster:mozilla.org
Discourse: https://discourse.mozilla.org/c/taskcluster/

If you’d like to investigate a live instance, the Mozilla Taskcluster deployment for community projects can be found here (no sign-in required): https://community-tc.services.mozilla.com/

Taskcluster - CI for Engineers

December 02, 2020 05:13 PM

September 01, 2020

Chris Cooper (coop)

Managing: team expectations

I don't know what I expected - Arrested Development

One of my biggest challenges when I began managing the Taskcluster team was simply getting my reports to talk to each other in a productive way. Per Conway’s Law, the micro-service architecture of Taskcluster reflected the knowledge silos on the team. Communication was erratic at best. Fortunately, transitions offer an ideal opportunity to establish norms, revisit old ways of work, and perhaps even try something new.

Following the lead of a colleague, at the start of my tenure I sat my new team down for an entire day and hashed out the communications issues. What emerged at the end of that discussion was a document that recorded all the expectations we had for each other as teammates. The document was part aspiration and part contract, but was essential for establishing a baseline of trust that we could use to work together going forward.

Fast-forward to 2020, and Mozilla is going through yet another transition. As the make-up and scope of my team changes again, it is useful to revisit the expectations document to make sure everyone is still on the same page. After consulting with the team, I also decided to publish our Team Expectations doc on Github in the hopes that it might benefit others.

This is partially self-serving: the Taskcluster team has many community contributors and the occasional intern, and we hope that by sharing our expectations more widely, we’ll foster a better contribution environment around our project.

If you’re interested in performing a similar exercise with your own team, be prepared to devote the time. I’d budget at least 4 hours to this process, depending on your team’s current level of dysfunction. We had the fortune in the before times to be able to do this in-person, but a series of video calls would accomplish the same goal.

Content-wise, the headings we came up with — Accountability, Communications, Planning and The Design Process: RFCs, Implementation and Review, Triage, Dealing with outages — are a good jumping-off point for the discussion but may or may not make sense depending on your field or responsibilities. Having done the process with a few different teams now, it’s important not to over-structure this at the start. There is a lot of value here in digression because that’s where you are most likely to find the areas where expectations are currently mismatched or unmet.

If you do try out, please let me know how it went, especially if you end up evolving the process. Hopefully it meets your expectations. ;)

September 01, 2020 10:28 PM

July 15, 2020

Armen Zambrano G. (@armenzg)

New backfill action

If you use Treeherder on repositories that are not Try, you might have used the backfill action. The backfill action takes a selected task and schedules it nine pushes back from the selected task. You can see the original work here and the follow up here.

<figcaption>The mda task on push 48a10a9249b0 has been backfilled</figcaption>

In the screenshot above you can see that the task mdaturned orange (implying that it failed). In the screenshot we can see that a Mozilla code sheriff has both retriggered the task four more times (you can see four more running tasks on the same push) and has backfilled the task on previous pushes. This is to determine if the regression was introduced on previous pushes or if the failure is due to an intermittent test failure.

<figcaption>Once you select a task and click on the hamburguer menu you can get to the backfill action</figcaption>

The difference with the old backfill action is threefold:

  1. The backfilled tasks include -bk in their symbol and group and it includes the revision of the originating task that was backfilled
  2. The backfilled tasks schedule the same set of manifests as the starting task
  3. The backfill action schedules a support action called backfill-task

Modified symbol for backfilled tasks

The modified symbol and group name for backfilled tasks is to:

  1. Show that it is a backfilled task (rather than schedule by normal scheduling) and that it can have a modified set of manifests (see next section)
  2. Show from which task it was backfilled from (by including the revision)
  3. Group backfilled tasks together to make it clear that they were not scheduled by normal means

I’ve also landed a change on Treeherder to handle this new naming and allow to filter out normal tasks plus backfilled tasks.

<figcaption>From this link you can filter out mda tasks plus mda backfilled tasks</figcaption>

Manifest-level backfilling

Point number two from the above list is what changes the most. Soon we will be landing a change on autoland that will schedule some test tasks with a dynamic set of manifests. This means that a task scheduled on push A will have a set of manifests (e.g. set X) and the same task on push B can have a different set of manifests (e.g. set Y).

The new backfill takes this into account by looking at the env variable MOZHARNESS_TEST_PATHS which contains the list of manifests and re-uses that value on backfilled tasks. This ensures that we’re scheduling the same set of manifests in every backfilled task.

Support actions

You can skip reading this section as this is more of an architectural change. This fixes the issue that backfilled tasks could not be re-run.

Backfilled tasks are now scheduled by a support action called backfill-task. If on Treeherder we filter by backfill tasks you can see both the initial backfillaction and the backfill-tasksupport action:

<figcaption>Two backfill actions were triggered on push 48a10a9249b0</figcaption>

The action backfill has scheduled nine backfill-task and those are in charge of scheduling the mda task on that push.

Thanks for reading. Please file a bug and CC me if you notice anything going wrong with it.

July 15, 2020 02:10 PM

July 03, 2020

Armen Zambrano G. (@armenzg)

In Filter Treeherder jobs by test or manifest path I describe the feature.

In Filter Treeherder jobs by test or manifest path I describe the feature. In this post I will explain how it came about.

I want to highlight the process between a conversation and a deployed feature. Many times, it is an unseen part of the development process that can be useful for contributors and junior developers who are trying to grow as developers.

Back in the Fall of 2019 I started inquiring into developers’ satisfaction with Treeherder. This is one of the reasons I used to go to the office once in a while. One of these casual face-to-face conversations led to this feature. Mike Conley explained to me how he would look through various logs to find a test path that had failed on another platform (see referenced post for further details).

After I understood the idea, I tried to determine what options we had to implement it. I wrote a Google Doc with various alternative implementations and with information about what pieces were needed for a prototype. I requested feedback from various co-workers to help discover blind spots in my plans.

Once I had some feedback from immediate co-workers, I made my idea available in a Google group (increasing the circle of people giving feedback). I described my intent to implement the idea and was curious to see if anyone else was already working on it or had better ideas on how to implement it. I did this to raise awareness in larger circles, reduce duplicate efforts and learn from prior work.

I also filed a bug to drive further technical discussions and for interested parties to follow up on the work. Fortunately, around the same time Andrew Halberstadt started working on defining explicitly what manifests each task executes before the tasks are scheduled (see bug). This is a major component to make the whole feature on Treeherder functional. In some cases, talking enough about the need can enlist others from their domains of expertise to help with your project.

At the end of 2019 I had time to work on it. Once I endlessly navigated through Treeherder’s code for a few days, I decided that I wanted to see a working prototype. This would validate its value and determine if all the technichal issues had been ironed out. In a couple of days I had a working prototype. Most of the code could be copy/pasted into Treeherder once I found the correct module to make changes in.

Finally, in January the feature landed. There were some small bugs and other follow up enhancements later on.

Stumbling upon this feature was great because on H1 we started looking at changing our CI’s scheduling to use manifests for scheduling instead of tasks and this feature lines up well with it.

July 03, 2020 05:55 PM

Filter Treeherder jobs by test or manifest path

At the beginning of this year we landed a new feature on Treeherder. This feature helps our users to filter jobs using test paths or manifest paths.

This feature is useful for developers and code sheriffs because it permits them to determine whether or not a test that fails in one platform configuration also fails in other ones. Previously, this was difficult because certain test suites are split into multiple tasks (aka “chunks”). In the screenshot below, you can see that the manifest path devtools/client/framework/browser-toolbox/test/browser.ini is executed in different chunks.

<figcaption>Showing tasks that executed a specific manifest path</figcaption>

NOTE: A manifest is a file that defines various test files, thus, a manifest path defines a group of test paths. Both types of paths can be used to filter jobs.

This filtering method has been integrated to the existing feature, “Filter by a job field” (the funnel icon). See below what the UI looks like:

<figcaption>Filter by test path</figcaption>

If you’re curious about the work you can visit the PR.

There’s a lot more coming around this realm as we move toward manifest-based scheduling in the Firefox CI instead of task-based scheduling. Stay tuned! Until then keep calm and filter away.

July 03, 2020 05:36 PM

May 15, 2020

Armen Zambrano G. (@armenzg)

Treeherder developer ergonomics

In the last few months I’ve worked with contributors who wanted to be selected to work on Treeherder during this year’s Google Summer of Code. The initial proposal was to improve various Treeherder developer ergonomics (read: make Treeherder development easier). I’ve had three very active contributors that have helped to make a big difference (in alphabetical order): Shubham, Shubhank and Suyash.

In this post I would like to thank them publicly for all the work they have accomplished as well as list some of what has been accomplished. There’s also listed some work from Kyle who tackled the initial work of allowing normal Python development outside of Docker (more about this later).

After all, I won’t be participating in GSoC due to burn-out and because this project is mostly completed (thanks to our contributors!). Nevertheless, two of the contributors managed to get selected to help with Treeherder (Suyash) and Firefox Accounts (Shubham) for GSoC. Congratulations!

Some of the developer ergonomics improvements that landed this year are:

There’s many more changes that got fixed by our contributors, however, I won’t cover all of them. You can see the complete list in here.

Thank you for reading this far and thanks again to our contributors for making development on Treeherder easier!

May 15, 2020 09:05 PM

January 31, 2020

Armen Zambrano G. (@armenzg)

Join Mozilla’s new chat rooms

For over a decade Mozilla has been using IRC to publicly chat with anyone interested to join the community. Recently, we’ve launched a replacement for it by creating a Mozilla community Matrix instance. I will be focusing on simply documenting what the process looks like to join in as a community member (without an LDAP account/Mozilla email address). For the background of the process you can read it here. Follow along the photos and what each caption says.

<figcaption>This is the landing page. Read the participation guideline and click on the “Sign In” button</figcaption>
This image shows another sign in dialogue. Follow the sign-in button and see if any of the options works for me.<figcaption>Follow the sign-in button. If none of the listed options in the next page works for you come back try “Create account”</figcaption>
<figcaption>Use one of the listed services or go back and create an account. Use the email address field only if you have an LDAP account (generally a Mozilla email address)</figcaption>
<figcaption>After you sign in you will get a system alert. You will need to accept the Privacy Notice and Terms and Conditions before you can use the service</figcaption>
<figcaption>Use the “Explore” button to find the room you’re interested in</figcaption>

If you have managed to get this far, Welcome to Mozilla’s Matrix! 😄

NOTE: If there’s an official page documenting the process I’m not aware of it. I will add it once it is published.

January 31, 2020 07:22 PM

October 24, 2019

Taskgraph is now deployed to the biggest mozilla-mobile projects

The 3-minute-video

See the video there, if it doesn’t display up here.

Context

Why Taskcluster?

It’s a fairly common practice to build and test every time someone makes a change in the code. In the industry, we call this process “Continuous Integration” (CI). Another good practice is to automate the deployment of your builds to end-users. This process is called “Continuous Deployment” (CD). There are several CI/CD products on the market. Mozilla has used some of them for years and still uses them in some projects. About 6 years ago, Mozilla needed a CI/CD product that did more than what was available and started Taskcluster. If you’re interested in knowing more about why we made Taskcluster, please let me know in the comments and I’ll write a dedicated post.

Since then, we’ve entirely migrated many Android projects like Firefox, Firefox Focus, Firefox for Amazon’s Fire TV, Android-Components, and the upcoming Firefox Preview to Taskcluster. The rationale for migrating off another CI/CD was usually the following: we want to ensure what we’re shipping to end-users comes from Mozilla, while still providing the development team an easy and consistent way to configure their tasks.

Taskcluster and task definitions

A task is an arbitrary piece of code that is executed by Taskcluster. We tell Taskcluster to execute a task by submitting some configuration, that we call the “task definition”. A task definition contains data about version control repository it deals with or what commands to run. As your project grows, it will likely need more than a single task to perform all actions. In this case, you need a graph of task definitions. You can submit a graph in different ways: either by manually entering each task on the task creator, by defining them all in a .taskcluster.yml file in your repository by defining a single task in .taskcluster.yml and letting this task generate the rest of the graph. We call this single task a “decision task”. It can be implemented: either by using one of the Taskcluster libraries (the Python one for instance), or by using a higher-level framework: taskgraph.

The above graph submission options are ordered by complexity. You may not want to start with option 3 immediately. Although, if your CI/CD pipeline deals with multiple platforms, multiple types of tests, and/or multiple types of pipelines, you may want solution 3b. More on this below.

Solution 1 Solution 1

Solution 2 Solution 2

Solution 3 Solution 3

Solution 3a Solution 3a: What’s inside the decision task

Solution 3b Solution 3b: Inside the decision task

Taskgraph was originally built for the most complex project, Firefox itself, and it was strongly tied to it. So, when a simpler project - Firefox Focus - came up a year and a half ago, we - the Development Team and Release Engineering - agreed on going with solution 2 and later on then 3a. Firefox Focus went great and became the base of a lot of Android projects. They have grown quite big since Firefox Focus started. The way CI/CD is configured there has grown on top of a code which wasn’t meant to be that big, and which was duplicated across projects.

Taskcluster and people

Moreover, people started to come from our main repository (where Firefox for Android is) to our other Android projects. With each project, they had to figure out how things work and Release Engineering has had to be involved in many changes, so we were losing the “provide the development team an easy way to configure their tasks” feature.

Here enters taskgraph

We know Android projects are becoming more and more complex, in terms of CI/CD. We know taskgraph is able to support thousands of jobs by splitting the complexity in small and dedicated files. We know Firefox developers have more or less knowledge about taskgraph to be able to add/modify their job without compromising the rest of the graph. So we decided to make taskgraph a more generic framework so Android projects can reuse it.

Taskgraph, the tour

In a few words

Like its name infers, taskgraph generates graphs of tasks for all types of events. Events can be “someone just pushed a new commit on the repository” or “someone just triggered a release”. Taskgraph knows what type of event happened and submits the corresponding graph to Taskcluster.

Main features

  1. It’s fast! Tens of thousands of tasks are generated in under a minute
  2. It deals with default values. Oftentimes you have to provide the same data for each task, taskgraph knows about the right defaults, so you can focus on what’s really important to your task
  3. It validates data before submitting anything to Taskcluster.
  4. It’s deterministic. You’ll get the exact same result by reusing a set of parameters from a run on another machine.
  5. It’s both configuration-oriented and programming-oriented. Want to avoid repeating the same configuration lines over and over? You can write a python function in a separate file

On Android projects, when we first implemented our simple solution based off of taskcluster libraries, we did have feature #1 (easy, when you deal with a handful of tasks), but we started to wait minutes to get a hundred tasks submitted. At some point, we needed feature #2, so we had to implement our own default values. We’ve never had feature #3 and #4. Depending on the Android project, feature #5 was more or less implemented.

Other features I like

  1. Docker images! We can create our build environments directly on Taskcluster as docker images and have our build tasks using them. We don’t need to publish the images somewhere, like on Docker hub.
  2. Cached tasks. Sometimes you just want to rebuild something when a subset of the code changes (for instance a Dockerfile). Taskgraph knows where to find these tasks and reuse them in the graph it submits
  3. Graphs that depend on other graphs. Cached tasks are for single tasks, but you can reuse entire graphs. This is useful in Firefox. We generate all the shippable builds whenever a push to the repository happens. Then, if we think they’re good enough, we promote them to be actually shipped.

To me, re-using taskgraph instead of reimplementing a new framework is today a huge win just for the sake of these features, even for small projects. We didn’t do it a year and a half ago, because taskgraph wasn’t a self-served module. Tom Prince put a lot of effort to make taskgraph generic enough to serve other projects than Firefox.

Introduction to taskgraph

Data flow, part 1

First part of the dataflow Hacking taskgraph is usually dealing with that part of the data flow

Kind.yml

In order to help taskgraph to tell if a task should end up in a graph, tasks are grouped in “kinds”. Kinds group tasks that are similar. For instance: You’d like to have 2 compilation tasks, one for a debug build and the other for an optimized one. Chances are both builds are generated with the same command, modulo a flag. In taskgraph, you will define both tasks under the same kind. Each kind is stored in its own kind.yml file. It’s the configuration-oriented part of taskgraph. You usually put raw data in them. There are some bits of simple logic that you can put in them. For example: job-defaults provides some default values for all jobs defined in the kind, it can be useful if the build tasks are generated with the same command.

Loader

The loader is in charge of taking every task in the kind, applying job-defaults and finding what are the right upstream dependencies. The dependency links are what make the graphs of tasks. For instance: In addition to having common values, both of your build tasks may depend on Docker images, where your full build environment is stored. The loader will output the 2 build tasks and set the docker image as their dependencies,

Transforms

Here comes the programming oriented part of taskgraph. The configuration defined in kind.yml is usually defined to be as simple as possible. Transforms take them and translate them into actual task definitions. Transforms can be shared among kinds, which gives a way to factorize common logic. Some transforms validate their input, ensuring the dataflow is sane. For example: For the sake of cost, Taskcluster enforces tasks to be deleted after a certain amount of time. The last transform ensures this value is valid and if it’s not defined (which usually happens) sets it to a year from now.

Data flow, part 2

Second part of the dataflow You may not need it, but that’s how optimization happens!

Target tasks

Taskgraph always generates the full graph, then it filters out what’s not needed. That’s what the target task phase does. For instance: If you want to ship a nightly build, target_tasks will only select the right tasks to build, sign, and publish this build.

Optimized tasks

Some tasks may have been already scheduled. If so, taskgraph takes them out of the target tasks. For example: If the nightly build task was made at the same time as the debug one, taskgraph can reuse the task and just submit the signing and publishing tasks.

Taskcluster client

At this point, taskgraph knows exactly what subgraph to submit. It delegates the submission to taskcluster via one of its client libraries. Tasks are then generated.

What’s next?

I really enjoyed “taskgraph-ifying” the most important mobile projects. We have leveraged a codebase that can scale while being able to handle edge cases. We’ve been able to factorize some of the common logic, which wasn’t possible with our initial solution. There’s still some improvement we can, and Mitch, Tom and I are working on improving the quality of life. Moreover, having taskgraph enables a better release workflow for Firefox Preview: we may have finer grained permission on who can ship a release. It requires more work and more blog posts, but taskgraph is a necessary stepping stone.

Further reading

Need any help?

If you’re stuck on something or Taskcluster isn’t behaving as it should, feel free to reach out to Release Engineering in #releaseduty-mobile (Slack).

Special thanks

Comments

You can read and leave comments on this Github issue.

October 24, 2019 12:24 PM

June 13, 2019

Chris AtLee (catlee)

Updated GPG key for signing Firefox Releases

The GPG key used to sign the Firefox release manifests is expiring soon, and so we're going to be switching over to new key shortly.

The new GPG subkey's fingerprint is 097B 3130 77AE 62A0 2F84 DA4D F1A6 668F BB7D 572E, and it expires 2021-05-29.

The public key can be fetched from KEY files from Firefox 68 beta releases, or from below. This can be used to validate existing releases signed with the current key, or future releases signed with the new key.

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June 13, 2019 04:50 PM

March 11, 2019

Chris AtLee (catlee)

Smaller Firefox Updates

Back in 2014 I blogged about several ideas about how to make Firefox updates smaller.

Since then, we have been able to implement some of these ideas, and we also landed a few unexpected changes!

tl;dr

It's hard to measure exactly what the impact of all these changes are over time. As Firefox continues to evolve, new code and dependencies are added, old code removed, while at the same time the build system and installer/updater continue to see improvements. Nevertheless I was interested in comparing what the impact of all these changes would be.

To attempt a comparison, I've taken the latest release of Firefox as of March 6, 2019, which is Firefox 65.0.2. Since most of our users are on Windows, I've downloaded the win64 installer.

Next, I tried to reverse some of the changes made below. I re-compressed omni.ja, used bz2 compression for the MAR files, re-added the deleted images and startup cache, and used the old version of mbsdiff to generate the partial updates.

Format Current Size "Old" Size Improvement (%)
Installer 45,693,888 56,725,712 19%
Complete Update 49,410,488 70,366,869 30%
Partial Update (from 64.0.2) 14,935,692 28,080,719 47%

Small updates FTW!

Ideally most of our users are getting partial updates from version to version, and a nearly 50% reduction in partial update size is quite significant! Smaller updates mean users can update more quickly and reliably!

One of the largest contributors to our partial update sizes right now are the binary diff size for compiled code. For example, the patch for xul.dll alone is 13.8MB of the 14.9MB partial update right now. Diffing algorithms like courgette could help here, as could investigations into making our PGO process more deterministic.

Here are some of the things we've done to reduce update sizes in Firefox.

Shipping uncompressed omni.ja files

This one is a bit counter-intuitive. omni.ja files are basically just zip files, and originally were shipped as regular compressed zips. The zip format compressed each file in the archive independently, in contrast to something like .tar.bz2 where the entire archive is compressed at once. Having the individual files in the archive compressed makes both types of updates inefficient: complete updates are larger because compressing (in the MAR file) already compressed data (in the ZIP file) doesn't yield good results, and partial updates are larger because calculating a binary diff between two compressed blobs also doesn't yield good results. Also, our Windows installers have been using LZMA compression for a long time, and after switching to LZMA for update compression, we can achieve much greater compression ratios with LZMA of the raw data versus LZMA of zip (deflate) compressed data.

The expected impact of this change was ~10% smaller complete updates, ~40% smaller partial updates, and ~15% smaller installers for Windows 64 en-US builds.

Using LZMA compression for updates

Pretty straightforward idea: LZMA does a better job of compression than bz2. We also looked at brotli and zstd for compression, but LZMA performs the best so far for updates, and we're willing to spend quite a bit of CPU time to compress updates for the benefit of faster downloads.

LZMA compressed updates were first shipped for Firefox 56.

The expected impact of this change was 20% reduction for Windows 64 en-US updates.

Disable startup cache generation

This came out of some investigation about why partial updates were so large. I remember digging into this in the Toronto office with Jeff Muizelaar, and we noticed that one of the largest contributors to partial update sizes were the startup cache files. The buildid was encoded into the header of startup cache files, which effectively changes the entire compressed file. It was unclear whether shipping these provided any benefit, and so we experimented with turning them off. Telemetry didn't show any impact to startup times, and so we stopped shipping the startup cache as of Firefox 55.

The expected impact of this change was about 25% for a Windows 64 en-US partial update.

Optimized bsdiff

Adam Gashlin was working on a new binary diffing tool called bsopt, meant to generate patch files compatible with bspatch. As part of this work, he discovered that a few changes to the current mbsdiff implementation could substantially reduce partial update sizes. This first landed in Firefox 61.

The expected impact of this change was around 4.5% for partial updates for Window 64 builds.

Removed unused theme images

We removed nearly 1MB of unused images from Firefox 55. This shrinks all complete updates and full installers by about 1MB.

Optimize png images

By using a tool called zopflipng, we were able to losslessly recompress PNG files in-tree, and reduce the total size of these files by 2.4MB, or about 25%.

Reduce duplicate files we ship

We removed a few hundred kilobytes of duplicate files from Firefox 52, and put in place a check to prevent further duplicates from being shipped. It's hard to measure the long term impact of this, but I'd like to think that we've kept bloat to a minimum!

March 11, 2019 10:03 PM

November 20, 2018

Chris AtLee (catlee)

PyCon Canada 2018

I've very happy to have had the opportunity to attend and speak at PyCon Canada here in Toronto last week.

PyCon has always been a very well organized conference. There are a wide range of talks available, even on topics not directly related to Python. I've attended previous PyCon events in the past, but never the Canadian one!

My talk was titled How Mozilla uses Python to Build and Ship Firefox. The slides are available here if you're interested. I believe the sessions were recorded, but they're not yet available online. I was happy with the attendance at the session, and the questions during and after the talk.

As part of the talk, I mentioned how Release Engineering is a very distributed team. Afterwards, many people had followup questions about how to work effectively with remote teams, which gave me a great opportunity to recommend John O'Duinn's new book, Distributed Teams.

Some other highlights from the conference:

  • CircuitPython: Python on hardware I really enjoyed learning about CircuitPython, and the work that Adafruit is doing to make programming and electronics more accessible.

  • Using Python to find Russian Twitter troll tweets aimed at Canada A really interesting dive into 3 million tweets that FiveThirtyEight made available for analysis.

  • PEP 572: The Walrus Operator My favourite quote from the talk: "Dictators are people too!" If you haven't followed Python governance, Guido stepped down as BDFL (Benevolent Dictator for Life) after the PEP was resolved. Dustin focused much of his talk about how we in the Python community, and more generally in tech, need to treat each other better.

  • Who's There? Building a home security system with Pi & Slack A great example of how you can get started hacking on home automation with really simple tools.

  • Froilán Irzarry's Keynote talk on the second day was really impressive.

  • You Don't Need That! Design patterns in Python My main takeaway from this was that you shouldn't try and write Python code as if it were Java or C++ :) Python has plenty of language features built-in that make many classic design patterns unnecessary or trivial to implement.

  • Numpy to PyTorch Really neat to learn about PyTorch, and leveraging the GPU to accelerate computation.

  • Flying Python - A reverse engineering dive into Python performance Made me want to investigate Balrog performance, and also look at ways we can improve Python startup time. Some neat tips about examining disassembled Python bytecode.

  • Working with Useless Machines Hilarious talk about (ab)using IoT devices.

  • Gathering Related Functionality: Patterns for Clean API Design I really liked his approach for creating clean APIs for things like class constructors. He introduced a module called variants which lets you write variants of a function / class initializer to support varying types of parameters. For example, a common pattern is to have a function that takes either a string path to a file, or a file object. Instead of having one function that supports both types of arguments, variants allows you to make distinct functions for each type, but in a way that makes it easy to share underlying functionality and also not clutter your namespace.

November 20, 2018 07:20 PM

September 20, 2018

Chris AtLee (catlee)

So long Buildbot, and thanks for all the fish

Last week, without a lot of fanfare, we shut off the last of the Buildbot infrastructure here at Mozilla.

Our primary release branches have been switched over to taskcluster for some time now. We needed to keep buildbot running to support the old ESR52 branch. With the release of Firefox 60.2.0esr earlier this month, ESR52 is now officially end-of-life, and therefore so is buildbot here at Mozilla.

Looking back in time, the first commits to our buildbot-configs repository was over 10 years ago on April 27, 2008 by Ben Hearsum: "Basic Mozilla2 configs". Buildbot usage at Mozilla actually predates that by at least two years, Ben was working on some patches in 2006.

Earlier in my career here at Mozilla, I was doing a lot of work with Buildbot, and blogged quite a bit about our experiences with it.

Buildbot served us well, especially in the early days. There really were no other CI systems at the time that could operate at Mozilla's scale.

Unfortunately, as we kept increasing the scale of our CI and release infrastructure, even buildbot started showing some problems. The main architectural limitations of buildbot we encountered were:

  1. Long lived TCP sessions had to stay connected to specific server processes. If the network blipped, or you needed to restart a server, then any jobs running on workers were interrupted.

  2. Its monolithic design meant that small components of the project were hard to develop independently from each other.

  3. The database schema used to implement the job queue became a bottleneck once we started doing hundreds of thousands of jobs a day.

On top of that, our configuration for all the various branches and platforms had grown over the years to a complex set of inheritance rules, defaults, and overrides. Only a few brave souls outside of RelEng managed to effectively make changes to these configs.

Today, much much more of the CI and release configuration lives in tree. This has many benefits including:

  1. Changes are local to the branches they land on. They ride the trains naturally. No need for ugly looooooops.

  2. Developers can self-service most of their own requests. Adding new types of tests, or even changing the compiler are possible without any involvement from RelEng!

Buildbot is dead! Long live taskcluster!

September 20, 2018 01:24 PM

April 25, 2018

Chris AtLee (catlee)

Firefox release speed wins

Sylvestre wrote about how we were able to ship new releases for Nightly, Beta, Release and ESR versions of Firefox for Desktop and Android in less than a day in response to the pwn2own contest.

People commented on how much faster the Beta and Release releases were compared to the ESR release, so I wanted to dive into the releases on the different branches to understand if this really was the case, and if so, why?

Chemspill timings

                    | Firefox ESR 52.7.2 | Firefox 59.0.1  | Firefox 60.0b4
 ------------------ | ------------------ | --------------- | --------------
 Fix landed in HG   | 23:33:06           | 23:31:28        | 23:29:54
 en-US builds ready | 03:19:03 +3h45m    | 01:16:41 +1h45m | 01:16:47 +1h46m
 Updates ready      | 08:43:03 +5h42m    | 04:21:17 +3h04m | 04:41:02 +3h25m
 Total              | 9h09m              | 4h49m           | 5h11m

(All times UTC from 2018-03-15 -> 2018-03-16)

Summary

via GIPHY

We can see that Firefox 59 and 60.0b4 were significantly faster to run than ESR 52 was! What's behind this speedup?

Release Engineering have been busy migrating release automation from buildbot to taskcluster . Much of ESR52 still runs on buildbot, while Firefox 59 is mostly done in Taskcluster, and Firefox 60 is entirely done in Taskcluster.

In ESR52 the initial builds are still done in buildbot, which has been missing out on many performance gains from the build system and AWS side. Update testing is done via buildbot on slower mac minis or windows hardware.

The Firefox 59 release had much faster builds, and update verification is done in Taskcluster on fast linux machines instead of the old mac minis or windows hardware.

The Firefox 60.0b4 release also had much faster builds, and ended up running in about the same time as Firefox 59. It turns out that we hit several intermittent infrastructure failures in 60.0b4 that caused this release to be slower than it could have been. Also, because we had multiple releases running simultaneously, we did see some resource contention for tasks like signing.

For comparison, here's what 60.0b11 looks like:

                    | Firefox 60.0b11
 ------------------ | --------------- 
 Fix landed in HG   | 18:45:45
 en-US builds ready | 20:41:53 +1h56m
 Updates ready      | 22:19:30 +1h37m
 Total              | 3h33m

Wow, down to 3.5 hours!

In addition to the faster builds and faster update tests, we're seeing a lot of wins from increased parallelization that we can do now using taskcluster's much more flexible scheduling engine. There's still more we can do to speed up certain types of tasks, fix up intermittent failures, and increase parallelization. I'm curious just how fast this pipeline can be :)

April 25, 2018 05:20 PM

April 20, 2018

Chris AtLee (catlee)

Taskcluster migration update: we're finished!

We're done!

Over the past few weeks we've hit a few major milestones in our project to migrate all of Firefox's CI and release automation to taskcluster.

Firefox 60 and higher are now 100% on taskcluster!

Tests

At the end of March, our Release Operations and Project Integrity teams finished migrating Windows tests onto new hardware machines, all running taskcluster. That work was later uplifted to beta so that CI automation on beta would also be completely done using taskcluster.

This marked the last usage of buildbot for Firefox CI.

Periodic updates of blocklist and pinning data

Last week we switched off the buildbot versions of the periodic update jobs. These jobs keep the in-tree versions of blocklist, HSTS and HPKP lists up to date.

These were the last buildbot jobs running on trunk branches.

Partner repacks

And to wrap things up, yesterday the final patches landed to migrate partner repacks to taskcluster. Firefox 60.0b14 was built yesterday and shipped today 100% using taskcluster.

A massive amount of work went into migrating partner repacks from buildbot to taskcluster, and I'm really proud of the whole team for pulling this off.

So, starting today, Firefox 60 and higher will be completely off taskcluster and not rely on buildbot.

It feels really good to write that :)

We've been working on migrating Firefox to taskcluster for over three years! Code archaeology is hard, but I think the first Firefox jobs to start running in Taskcluster were the Linux64 builds, done by Morgan in bug 1155749.

Into the glorious future

It's great to have migrated everything off of buildbot and onto taskcluster, and we have endless ideas for how to improve things now that we're there. First we need to spend some time cleaning up after ourselves and paying down some technical debt we've accumulated. It's a good time to start ripping out buildbot code from the tree as well.

We've got other plans to make release automation easier for other people to work with, including doing staging releases on try(!!), making the nightly release process more similar to the beta/release process, and for exposing different parts of the release process to release management so that releng doesn't have to be directly involved with the day-to-day release mechanics.

April 20, 2018 04:50 PM

Chris Cooper (coop)

New to me: the Taskcluster team

All entities move and nothing remains still.

At this time last year, I had just moved on from Release Engineering to start managing the Sheriffs and the Developer Workflow teams. Shortly after the release of Firefox Quantum, I also inherited the Taskcluster team. The next few months were *ridiculously* busy as I tried to juggle the management responsibilities of three largely disparate groups.

By mid-January, it became clear that I could not, in fact, do it all. The Taskcluster group had the biggest ongoing need for management support, so that’s where I chose to land. This sanity-preserving move also gave a colleague, Kim Moir, the chance to step into management of the Developer Workflow team.

Meet the Team

Let me start by introducing the Taskcluster team. We are:

We are an eclectic mix of curlers, snooker players, pinball enthusiasts, and much else besides. We also write and run continous integration (CI) software at scale.

What are we doing?

Socrates gets booked
The part I understand is excellent, and so too is, I dare say, the part I do not understand…

One of the reasons why I love the Taskcluster team so much is that they have a real penchant for documentation. That includes their design and post-mortem processes. Previously, I had only managed others who were using Taskcluster…consumers of their services. The Taskcluster documentation made it really easy for me to plug-in quickly and help provide direction.

If you’re curious about what Taskcluster is at a foundational level, you should start with the tutorial.

The Taskcluster team currently has three, big efforts in progress.

1. Redeployability

Many Taskcluster team members initially joined the team with the dream of building a true, open source CI solution. Dustin has a great post explaining the impetus behind redeployability. Here’s the intro:

Taskcluster has always been open source: all of our code is on Github, and we get lots of contributions to the various repositories. Some of our libraries and other packages have seen some use outside of a Taskcluster context, too.

But today, Taskcluster is not a project that could practically be used outside of its single incarnation at Mozilla. For example, we hard-code the name taskcluster.net in a number of places, and we include our config in the source-code repositories. There’s no legal or contractual reason someone else could not run their own Taskcluster, but it would be difficult and almost certainly break next time we made a change.

The Mozilla incarnation is open to use by any Mozilla project, although our focus is obviously Firefox and Firefox-related products like Fennec. This was a practical decision: our priority is to migrate Firefox to Taskcluster, and that is an enormous project. Maintaining an abstract ability to deploy additional instances while working on this project was just too much work for a small team.

The good news is, the focus is now shifting. The migration from Buildbot to Taskcluster is nearly complete, and the remaining pieces are related to hardware deployment, largely by other teams. We are returning to work on something we’ve wanted to do for a long time: support redeployability.

We’re a little further down that path than when he first wrote about it in January, but you can read more about our efforts to make Taskcluster more widely deployable in Dustin’s blog.

2. Support for packet.net

packet.net provides some interesting services, like baremetal servers and access to ARM hardware, that other cloud providers are only starting to offer. Experiments with our existing emulator tests on the baremetal servers have shown incredible speed-ups in some cases. The promise of ARM hardware is particularly appealing for future mobile testing efforts.

Over the next few months, we plan to add support for packet.net to the Mozilla instance of Taskcluster. This lines up well with the efforts around redeployability, i.e. we need to be able to support different and/or multiple cloud providers anyway.

3. Keeping the lights on (KTLO)

While not particularly glamorous, maintenance is a fact of life for software engineers supporting code that in running in production. That said, we should actively work to minimize the amount of maintenance work we need to do.

One of the first things I did when I took over the Taskcluster team full-time was halt *all* new and ongoing work to focus on stability for the entire month of February. This was precipitated by a series of prolonged outages in January. We didn’t have an established error budget at the time, but if we had, we would have completely blown through it.

Our focus on stability had many payoffs, including more robust deployment stories for many of our services, and a new IRC channel (#taskcluster-bots) full of deployment notices and monitoring alerts. We needed to put in this stability work to buy ourselves the time to work on redeployability.

What are we *not* doing?

With all the current work on redeployability, it’s tempting to look ahead to when we can incorporate some of these improvements into the current Firefox CI setup. While we do plan to redeploy Firefox CI at some point this year to take advantage of these systemic improvements, it is not our focus…yet.


One of the other things I love about the Taskcluster team is that they are really good at supporting community contribution. If you’re interested in learning more about Taskcluster or even getting your feet wet with some bugs, please drop by the #taskcluster channel on IRC and say Hi!

April 20, 2018 01:03 PM

March 03, 2018

Chris AtLee (catlee)

Taskcluster migration update, the sequel

Firefox, now 100% buildbot-free!

First, the good news - Developer Edition 60.0b1 will be the first release in nearly 10 years done without using buildbot. This is an amazing milestone, and I'm incredibly proud of everybody who has contributed to make this possible!

Long time, no update

How did we get here? It's been, uh, almost 6 months since I last posted an update about our migration to Taskcluster.

In my last update, I described our plans for the end of 2017...

We're on track to ship builds produced in Taskcluster as part of the
56.0 release scheduled for late September. After that the only Firefox
builds being produced by buildbot will be for ESR52.

Meanwhile, we've started tackling the remaining parts of release
automation. We prioritized getting nightly and CI builds migrated to
Taskcluster, however, there are still parts of the release process
still implemented in Buildbot.

We're aiming to have release automation completely migrated
off of buildbot by the end of the year. We've already seen many
benefits from migrating CI to Taskcluster, and migrating the release
process will realize many of those same benefits.

How'd we do?

We're past the end of 2017, so how are we doing?

Well, we successfully shipped 56.0 with builds produced in Taskcluster. Our big Firefox Quantum release (57.0), was also shipped with builds produced by Taskcluster.

(side note: 57 had the most complex update scenarios we've ever had to support for Firefox...a subject for another post!)

Release scheduling

Post-56.0, our release process was using Taskcluster exclusively for producing the initial builds, and all the release process scheduling. We were still using Buildbot for many of the post-build tasks, like l10n repacks, publishing updates, pushing files to S3, etc. Once again we relied on the buildbot bridge to allow us to integrate existing buildbot components with the newer taskcluster pipeline. I learned from Kim Moir that this is a great example of the strangler pattern.

In the fall of 2017, we decided to begin migrating all of the scheduling logic for release automation into taskcluster using the in-tree taskgraph scheduling system. We did this for a few reasons...

  1. Having the release scheduling logic ride the trains is much more maintainable. Previous to this we had an externally defined release pipeline in our releasetasks repo. It was hard to keep this repository in sync with changes required for beta/release and ESR branches.

  2. More importantly, having the release scheduling logic in-tree meant that we could then rely on chain-of-trust to verify artifacts produced by the release pipeline.

  3. We felt that having the complete release pipeline defined in taskcluster would make it easier for us to tackle the remaining buildbot bridge tasks in parallel.

We hit this milestone in the 58 cycle. Starting with 58.0b3, Firefox and Fennec releases were completely scheduled using the in-tree taskgraph generation. We also migrated over the l10n repacks at the same time, removing a longstanding source of problems where repacks would fail when we first got to beta due to environmental differences between taskcluster and buildbot.

No-BBB Releases

Still, as of 58, much of release automation still ran on buildbot, even if Taskcluster was doing all the scheduling.

Since December, we've been working on removing these last few pieces of buildbot from the release process. Progress was initially a bit slow, given Austin and Christmas, but we've been hard at work in the new year.

That brings us to today.

We've moved uptake monitoring, update verify (and made it 2x faster too!), update submission, final verify, bouncer submission, version bumping and tagging, balrog submission all to run in Taskcluster via various kinds of scriptworkers.

As I mentioned above, DevEdition 60.0b1 will be the first release in nearly 10 years done without using buildbot. The rest of the 60 release cycle will follow suit, and once 60 hits the release channel, only ESR52 will remain on buildbot!

March 03, 2018 12:26 PM

February 16, 2018

Chris Cooper (coop)

Experiments in productivity: the shared bug queue

Maybe you have this problem too

You manage or are part of a team that is responsible for a certain functional area of code. Everyone on the team is at different points in there career. Some people have only been there a few years, or maybe even only a few months, but they’re hungry and eager to learn. Other team members have been around forever, and due to that longevity, they are go-to resources for the rest of your organization when someone needs help in that functional area. More-senior people get buried under a mountain of review requests, while those less-senior engineers who are eager to help and grow their reputation get table scraps.

This is the situation I walked into with the Developer Workflow team.

This was the first time that Mozilla had organized a majority (4) of build module peers in one group. There are still isolated build peers in other groups still, but we’ll get to that in a bit.

With apologies to Ted, he’s the elder statesman of the group, having once been the build module owner himself before handing that responsiblity off to Greg (gps), the current module owner. Ted has been around Mozilla for so long that he is a go-to resource for not only build system work but many other projects, e.g. crash analysis, he’s been involved with. In his position as module owner, Greg bears the brunt of the current review workload for the build system. He needs to weigh-in on architectural decisions, but also receives a substantial number of drive-by requests simply because he is the module owner.

Chris Manchester and Mike Shal by contrast are relatively new build peers and would frequently end up reviewing patches for each other, but not a lot else. How could we more equitably share the review load between the team without creating more work for those engineers who were already oversubscribed?

Enter the shared bug queue

When I first came up with this idea, I thought that certainly this must have been tried at some point in the history of Mozilla. I was hoping to plug into an existing model in bugzilla, but alas, such a thing did not already exist. It took a few months of back-and-forth with our reisdent Bugmaster at Mozilla, Emma, to get something setup, but by early October, we had a shared queue in place.

How does it work?

ICP

We created a fictitious meta-user, core-build-config-reviews@mozilla.bugs. Now whenever someone submits a patch to the Core::Build Config module in bugzilla, the suggested reviewer always defaults to that shared user. Everyone on the teams watches that user and pulls reviews from “their” queue.

That’s it. No, really.

Well, okay, there’s a little bit more process around it than that. One of the dangers of a shared queue is that since no specific person is being nagged for pending reviews, the queue could become a place where patches go to die. As with any defect tracking system, regular triage is critically important.

Is it working?

In short: yes, very much so.

Subjectively, it feels great. We’ve solved some tricky people problems with a pretty straightforward technical/process solution and that’s amazing. From talking to all the build peers, they feel a new collective sense of ownership of the build module and the code passing through it. The more-senior people feel they have more time to concentrate on higher level issues or deeper reviews. The less-senior people are building their reputations, both among the build peers and outside the group to review requesters.

Numerically speaking, the absolute number of review requests for the Core::Build Config module is consistent since the adoption of the shared queue. The distribution of actual reviewers has changed a lot though. Greg and Ted still end up reviewing their share of escalated requests — it’s still possible to assign reviews to specific people in this system — but Mike Shal and Chris have increased their review volume substantially. What’s even more awesome is that the build peers who are *NOT* in the Developer Workflow team are also fully onboard, regularly pulling reviews off the shared queue. Kudos to Nick Alexander, Nathan Froyd, Ralph Giles, and Mike Hommey for also embracing this new system wholeheartedly.

The need for regular triage has also provided another area of growth for the less-senior build peers. Mike Shal and Chris Manchester have done a great job of keeping that queue empty and forcing the team to triage any backlog each week in our team meeting.

Teh Future

When we were about to set this up in October, I almost pulled the plug.

Over the next six months, Mozilla is planning to switch code review tools from mozreview/splinter to phabricator. Phabricator has more modern built-in tools like Herald that would have made setting up this shared queue a little easier, and that’s why I paused…briefly

Phabricator will undoubtedly enable a host of quality-of-life improvements for developers when it is deployed, but I’m glad we didn’t wait for the new system. Mozilla engineers are already getting accustomed to the new workflow and we’re reaping the benefits *right now*.

February 16, 2018 08:42 PM

February 02, 2018

Chris Cooper (coop)

Welcome, Connor!

Connor McDavid
<figcaption>This is *not* our Connor.</figcaption>

This post is *ahem* several months overdue, but I’m happy to welcome Connor Sheehan to the team.

Connor was a two-time intern with the Mozilla release engineering team. In that capacity, he became well acquainted with some of the bottlenecks in our CI system. We’ve brought him onboard to assist gps with stabilizing and scaling our mercurial infrastructure.

Welcome, Connor!

February 02, 2018 02:46 PM

November 20, 2017

Chris Cooper (coop)

Work Week Logistics, Revisited

I’ve written before about how to be productive when distributed teams get together and was anxious to try it out on my “new” (read: six-month-old) team, Developer Workflow. As mentioned in that previous post, we just had a work week in Mountain View, so here’s a quick recap.

Process Improvements

We often optimize work week location around where the fewest people would need to travel to attend. While this does make things logistically easier, it also introduces imbalance. Some people will have traveled very far, while some people will be able to sleep in their own beds. Conversely, the local people may feel they need to go home every night in order to be with their partners/families/cats and may miss out on the informal bonding that can happen at group dinners and such.

We had originally intended to meet in San Francisco, but other conferences had jacked up hotel rates, so we decided to decamp to the Valley. I offered to have the SF residents book rooms to avoid the daily commute up and down the peninsula. They didn’t all take me up on it, but it was an opportunity to put everyone on more equal footing.

Schedule-wise, I set things up so that we had our discussion and planning pieces in the morning each day while we were still fresh and caffeinated. After lunch, we would get down to hacking on code. Ted threw together a tracking tool to help visualize the Makefile burndown. Ted is also great at facilitating meetings, keeping us on track especially later in the week as we all started to fade.

Accomplishments

So what did we actually get done? Like the old adage about station wagon full of tapes, never underestimate the review bandwidth of 4 build peers hacking in a room together for an afternoon. We accomplished quite a bit during our time together.

Aside from the 2018 planning detailed in the previous post, we also met with mobile build peer Nick Alexander and planned how to handle mobile Makefiles. The mobile version of Firefox now builds with gradle, so it was important not to step on each others toes. Another huge proportion of the remaining Makefiles involve l10n. We figured out how to work-around l10n for now, i.e. don’t break repacks, to get a tup build working, and we’ve setup a meeting with l10n team for Austin to discuss their plans for langpacks and a future that might not involve makefiles at all. The l10n stuff is hairy, and might be partially my fault (see previous comment re: cargo-culting), so thanks to my team for not shying away from it.

On a concrete level, Ted reports that we’ve removed 13 Makefiles and ~100 lines of other Makefile content in the past month, much of which happened over the past few weeks. Greg has also managed to remove big pieces of complexity from client.mk, assisted by reviews from Chris, Mike, Nick and other build peers. We’re getting into the trickier bits now, but we’re persevering.

All in all, a very successful work week with my “new” team. I continue to find subtle ways to make these get-togethers more effective.

November 20, 2017 03:14 PM

November 16, 2017

Chris Cooper (coop)

Introducing The Developer Workflow Team

I’ve neglected to write about the *other* half of my team, not for any lack of desire to do so, but simply because the code sheriffing situation was taking up so much of my time. Now that the SoftVision contractors have gained the commit access required to be fully functional sheriffs, I feel that I can shift focus a bit.

Meet the team

The other half of my team consists of 4 Firefox build system peers. My team consists of:

Justice League Unlimited

When the group was first established, we talked a lot about what we wanted to work on, what we needed to work on, and what we should be working on. Those discussions revealed the following common themes:

Based on that list of themes, we’ve adopted the moniker of “Developer Workflow.” We are all build peers, yes, but to pigeon-hole ourselves as the build system group seemed short-sighted. Our unique position at the intersection of the build system, VCS, and other services meant that our scope needed to match what people expect of us anyway.

While new to me, Developer Workflow is a logical continuation of build system tiger team organized by David Burns in 2016. This is the same effort that yielded sea change improvements such as artifact builds and sccache.

In many ways, I feel extremely fortunate to be following on the heels of that work. During the previous year, all the members of my team formed the working relationships they would need to be more successful going forward. All the hard work for me as their manager was already done! ;)

What are we doing

We had our first, dedicated work week as a team last week in Mountain View. Aside from getting to know each other a little better, during the week we hashed out exactly what our team will be focused on next year, and made substantial progress towards bootstrapping those efforts.

Next year, we’ll be tackling the following projects:

What are we *not* doing

It’s important to be explicit about things we won’t be tackling too, especially when it’s been unclear historically or where there might be different expectations.

The biggest one to call out here is github integration. Many teams at Mozilla are using github for developing standalone projects or even parts of Firefox. While we’ve had some historical involvement here and will continue to consult as necessary, other teams are better positioned to drive this work.

We are also not currently exploring moving Windows builds to WSL. This is something we experimented with in Q3 this year, but build performance is still so slow that it doesn’t warrant further action right now. We continue to follow the development of WSL and if Microsoft is able to fix filesystem performance, we may pick this back up.

November 16, 2017 02:12 PM

October 25, 2017

Chris Cooper (coop)

Code sheriffing @ Mozilla: Past, Present, and Future

In a github world, developers have certain baseline expectations about interacting with source code and the tooling around it. These expectations can color their choices about which projects to contribute to. If Mozilla wants to compete with other companies and open source projects for developer mindshare (and code), we need to evolve the way we develop and distribute software. Code sheriffing and its associated tooling is one piece of that puzzle.

I inherited the Mozilla code sheriff team back in April. I didn’t initially think anything needed to change with sheriffing at Mozilla. Things had been “fine” for a while, so why rock the boat?

By nature, I dug into the history of my new team when I inherited them. What follows is a brief retrospective of sheriffing at Mozilla, the changes we’re undergoing right now, and my vision for how it might change in the future.

Past

Back to the Future III

I’ve been at Mozilla long enough now to remember when developers themselves acted as code sheriffs. In the beginning, every developer at Mozilla (myself included) rotated through the position1. Some developers were quite conscientious about sheriffing, others never even realized it was their turn. There was no formal training. Not surprisingly, the results were…uneven.

As the number of developers and the volume of code increased, this model became untenable. Code sheriffing as a well-defined role didn’t exist at Mozilla until 2012, initially coming as a response to the staffing increase in the lead-up to Firefox 4. At the same time, Mozilla was moving away from a “strict” waterfall development model tied to Tinderbox. Our new buildbot-based approach to CI allowed us to land more code, more quickly. Dedicated sheriffs were needed to make sense of it all. Even then, in true Mozilla fashion, sheriffing was an activity that blurred the lines between community and staff. Some of the most dedicated code sheriffs we have ever had were/are volunteers.

Whether staff or community, code sheriffs became de facto stewards of code quality. They were responsible for daily merges, selecting changesets with the lowest number of intermittent failures that would be suitable for inclusion in Nightly releases. When things broke, the sheriffs were responsible for backing out code, and even closing the development trees if the situation became sufficiently dire.

With the opening of the Mozilla office in Taipei, and the associated re-tasking of two QA resources as code sheriffs in that office, Mozilla almost had around-the-clock (24/7) coverage for code sheriffing, provided no one ever got sick or took a vacation.

We persevered in this model for a few years, and our developers understandably became accustomed to the freedom it provided them. Developers could functionally land their code and not worry about the outcome: the code sheriffs would ping them if any follow-up action was required. Fire-and-forget, if you will.

Sadly, in June 2017 our last Taipei sheriff resigned, leaving us with a glaring hole in our coverage. Even with community assistance, there were 8-10 hours per day with *no* active sheriffing. This led to an increase in tree closing events as sheriffs often needed to determine the root cause for a failure that had many commits on top of it already. Complaints started coming in about delays in landing code, and also about classification errors, e.g. permanent failures wrongly triaged as intermittent due to the time pressures of working in this mode. People were not happy, least of all the sheriffs.

This is when I realized I needed to rethink how sheriffing at Mozilla should work.

Present

Back to the Future

The knee-jerk reaction would have been to simply hire another sheriff in Taipei, but that still would have left us vulnerable to illness, vacation, and further employment changes. Luckily, another solution presented itself.

Mozilla has an established history of working with SoftVision. I enlisted their help myself a few years ago when I was working in releng to help address our buildduty problem. It came to my attention that SoftVision was creating a 24/7 support service, and I decided to give it a try. That’s where we are now.

The SoftVision sheriffing contractors started in late August. They have spent the last two months learning (and then practicing) how to classify automation failures. The harder piece is learning how to properly select mergeable changesets and perform backouts. Mozilla guards the kind of source control access required to perform these code sheriffing activities pretty closely; it’s not something we simply give away. The contractors are slowly building that trust the same as any other contributor would. We’re getting there though:

Once the SoftVision sheriffs are fully up-to-speed, they will be available 24/7 to assist developers, and to further the Mozilla mission with the usual array of merges, backouts, uplifts, and tree closures.

Right now, we are relying on the magnanimity of the former sheriffs and community sheriffs to help bridge the gap while the contractors are training up. It’s true, sheriffs throughput is still not back to the level before we lost our sheriff in Taipei, but I can see the light at the end of the tunnel.

Future

Back to the Future II

How can I be sure that light isn’t a train? Well, that’s the trick, isn’t it?

In retrospect, it was naïve of me to think that sheriffing could have existed for any length of time the way it was. Sheriffs felt enormous pressure to work longer hours than they should have because the trees needed to stay open, and “if not them, then who?” The human toll on those performing the work. whether staff or volunteer, was simply too high.

Yes, for the near-future at least, the SoftVision contractors will continue to perform merges and backouts as required in the model to which we’ve become accustomed. That work is still very operational, hands-on, and prone to burnout, and that’s where I think the biggest opportunity for change will come going forward.

Mozilla currently has two integrations branches – mozilla-inbound and autoland – in addition to mozilla-central. This makes life much harder for sheriffs because they need to merge code three-ways between the different branches. When bad code gets merged around accidentally, we are almost forced to close the trees while we recover.

The obvious change is to simplify the process and remove one of the integration branches. This might actually be feasible in the near future. With the announcement of Mozilla’s adoption of phabricator, 99.9% of code should eventually be able to land directly in the autoland repo, allowing us to decommission the mozilla-inbound repo. Once we return to a single integration branch, developer workflows can be much more streamlined, and streamlined workflows are ideal targets for automation.

My ideal future developer workflow would be:

There are no code sheriffs in that picture at all. That’s a good thing.2

There’s a gulf of tooling improvements between where we are and that potential future, but if Mozilla wants to keep increasing the pace of development and attracting the best developers, I think the tooling investment is one we need to make.


1. Hilariously, a version of that sheriffing calendar still exists, projecting sheriff duty off into the future for a bunch of developers who haven’t even been at Mozilla for years.
2. I’m not naïve enough to think we won’t need *any* sheriffs. Even Facebook’s model still needs some.

October 25, 2017 03:04 PM

August 30, 2017

Chris AtLee (catlee)

Taskcluster migration update

All your nightlies are belong to Taskcluster

In January I announced that we had just migrated Linux nightly builds to Taskcluster.

We completed a huge milestone in July: starting in Firefox 56, we've been doing all our nightly Firefox builds in Taskcluster.

https://media.giphy.com/media/MOWPkhRAUbR7i/giphy.gif

This includes all Windows, macOS, Linux, and Android builds. You can see all the builds and repacks on Treeherder.

In August, after 56 merged to Beta, we've also been doing our Firefox Beta builds using Taskcluster. We're on track to be shipping Firefox 56, built from Taskcluster to release users at the end of September.

Windows and macOS each had their own challenges to get them ready to build and ship to our nightly users.

Windows signing

We've had Windows builds running in Taskcluster for quite a while now. The biggest missing piece stopping us from shipping these builds was signing. Windows builds end up being a bit complicated to sign.

First, each compiled .exe and .dll binary needs to be signed. Signing binaries in windows changes their contents, and so we need to regenerate some files that depend on the exact contents of binaries. Next, we need to create packages in various formats: a "setup.exe" for installing Firefox, and also MAR files for updates. Each of these package formats in turn need to be signed.

In buildbot, this process was monolithic. All of the binary generation and signing happened as part of the same build process. The same process would also publish symbols to the symbol server and publish updates to Balrog The downside of this monolithic process is that it adds additional dependencies to the build, which is already a really long process. If something goes wrong with signing, or publishing updates, you don't want to have to restart a 2 hour build!

As part of our migration to Taskcluster, we decided that builds should minimize their external dependencies. This means that the build task produces only unsigned binaries, and it is the responsibility of downstream tasks to sign them. We also wanted discrete tasks for symbol and update submission.

One wrinkle in this approach is that the logic that defines how to create a setup.exe package or a MAR file lives in tree. We didn't want to run that code in the same context as the code that generates signatures.

Our solution to this was to create a sequence of build -> signing -> repackage -> signing tasks. The signing tasks run in a restricted environment while the build and repackage tasks have access to the build system in order to produce the required artifacts. Using the chain of trust, we can demonstrate that the artifacts weren't tampered with between intermediate tasks.

Finally, we need to consider l10n repacks. We ship Firefox in over 90 locales. The repacking process downloads the en-US build and replaces the English strings with localized strings. Each of these repacks needs to be based on the signed en-US build. Each will also generate its own setup.exe and complete MAR for updates.

macOS performance (and why your build directory matters)

Like Windows, we've had macOS builds running on Taskcluster for a long time. Also like Windows, we had to solve signing for macOS.

However, the biggest blocker for the macOS build migration, was a performance bug. Builds produced on Taskcluster showed some serious performance regressions as compared to the builds produced on buildbot.

Many very smart people looked at this bug since it was first discovered in February. They compared library versions being used. They compared compiler versions and compiler flags. They even inspected the generated assembly code from both systems.

Mike Shal stumbled across the first clue to what was going on in June: if he stripped the Taskcluster binaries, then the performance problems disappeared! At this point we decided that we could go ahead and ship these builds to nightly users, knowing that the performance regression would disappear on beta and release.

Later on, Mike realized that it's not the presence or absence of symbols in the binary that cause the performance hit, it's what directory the builds are done in. On buildbot we build under /builds/..., and on Taskcluster we build under /home/...

https://media.giphy.com/media/zjQrmdlR9ZCM/giphy.gif

Read the bug for more gory details. This is definitely one of the strangest bugs I've seen.

Lessons learned

We learned quite a bit in the process of migrating Windows and macOS nightly builds to Taskcluster.

First, we gained a huge amount of experience with the in-tree scheduling system. There's a bit of a learning curve to climb, but it's an extremely powerful and flexible system. Many kudos to Dustin for his work creating the foundation of this system here. His blog post, "What's So Special About "In-Tree"?", is a great explanation of why having this code as part of Firefox's repository is so important.

One of the killer features of having all the scheduling logic live in-tree is that you can do quite a bit of work locally, without requiring any build infrastructure. This is extremely useful when working on the complex build / signing / repackage sequence of tasks described above. You can make your changes, generate a new task graph, and inspect the results.

Once you're happy with your local changes, you can push them to try to validate your local testing, get your patch reviewed, and then finally landed in gecko. Your scheduling changes will take effect as soon as they land into the repo. This made it possible for us to do a lot of testing on another project branch, and then merge the code to central once we were ready.

What's next?

We're on track to ship builds produced in Taskcluster as part of the 56.0 release scheduled for late September. After that the only Firefox builds being produced by buildbot will be for ESR52.

Meanwhile, we've started tackling the remaining parts of release automation. We prioritized getting nightly and CI builds migrated to Taskcluster, however, there are still parts of the release process still implemented in Buildbot.

We're aiming to have release automation completely migrated off of buildbot by the end of the year. We've already seen many benefits from migrating CI to Taskcluster, and migrating the release process will realize many of those same benefits.

Thanks!

Thank you for reading this far!

Members from the Release Engineering, Release Operations, Taskcluster, Build, and Product Integrity teams all were involved in finishing up this migration. Thanks to everyone involved (there are a lot of you!) to getting us across the finish line here.

In particular, if you come across one of these fine individuals at the office, or maybe on IRC, I'm sure they would appreciate a quick "thank you":

  • Aki Sasaki
  • Dustin Mitchell
  • Greg Arndt
  • Joel Maher
  • Johan Lorenzo
  • Justin Wood
  • Kim Moir
  • Mihai Tabara
  • Mike Shal
  • Nick Thomas
  • Rail Aliiev
  • Rob Thijssen
  • Simon Fraser
  • Wander Costa

August 30, 2017 09:40 AM

June 13, 2017

Part 4: How Mozilla publishes APKs onto Google Play Store, in a reasonably secure and automated way

The Release Engineering team fully-automated the publication of Firefox for Android in version 53.0. Let’s see what was already there and how things have changed since version 53.0.

This blog post is a part of a serial. Checkout the other posts:

  1. How did the project start?
  2. Presentation of the solution
  3. 5 things I would have loved knowing about Google Play
  4. What’s next? Want to contribute? & Special thanks [Here]

What’s next? Want to contribute?

The initial publication was the first big step of the project. The next big one will be to expand the release workflow to simplify what percentage of the user base is getting the latest update.

If you want to contribute, there are also a few open bugs. You might also want to take look at MozApkPublisher and pushapkscript to see how we added our checks.

Finally, if you have some stories on how you use Google Play you would like to share, questions or comments about our tools, please leave a comment.

Special thanks

A lot of people were involved in a way or another in this project. By alphabetical order:

Comments

You can read and leave comments on this Github issue.

June 13, 2017 08:56 AM

June 12, 2017

Part 3: How Mozilla publishes APKs onto Google Play Store, in a reasonably secure and automated way

The Release Engineering team fully-automated the publication of Firefox for Android in version 53.0. Let’s see what was already there and how things have changed since version 53.0.

This blog post is a part of a serial. Checkout the other posts:

  1. How did the project start?
  2. Presentation of the solution
  3. 5 things I would have loved knowing about Google Play [Here]
  4. What’s next? Want to contribute? & Special thanks

5 things I would have loved knowing about Google Play

This part is more oriented to personal takeaways and a couple of questions that remain unanswered.

It is easy to publish an APK that is not localized

A few checks done in pushapk_scriptworker are actually because of previous errors. The number of locales is one of them. A few weeks after Fennec Aurora was shipped to Google Play, some users started to see their browser in English, even though their phone is set in a different locale and Aurora used to be in their own locales.

Like said previously, APKs were originally uploaded via a script. This was true also for the first Aurora APKs. Furthermore, automation on Taskcluster was first tried on Aurora. When I started to roll these bits out, there was a configuration issue. Pushapk_scriptworker picked the en-US-only-APK, instead of the multi-locale one. The fix was fairly simple: just change the APK locations.

Google Play has a lot of ways to detect wrong APKs: by signatures, by package name (none of the Firefox versions share the same one), by version code, and some others. Although, it doesn’t warn about a big change in:

Of course, from one stable version to another, a lot of files may change in the archive. Asking Google to watch out for everything doesn’t seem reasonable. Although, when I started working on Google Play, it left me the feeling of being well-hardened. At that time, I thought Google Play did check the locales within an APK.

The consequence I take away: If your app has different build flavors (like single vs multi-locales), I recommend you write your own sanity checks, first.

Locales on the Play Store are independent from locales in APK

It might sound obvious after explaining of the previous issue, but this error message confused several Mozillians:

Tried to set recent changes text for APK version 12345678 for language es-US. Language is not associated with the app.

We hit it with a couple of locales, at pace of 1 per month, approximately. Like explained in the architecture part, locales are defined in an external service, stores_l10n. We have had many theories about it:

Actually, the fix ended up being simple. “Recent changes” is something we want to update on every new APK. But because the descriptions were more set in stone, they were not a part of the automated workflow. Actually, stores_l10n released had recently released new locales each time we hit the problem. That error message was actually telling us the descriptions of these new locales had never been uploaded. Once we figured this out, it became a part of the regular update workflow.

You cannot catch everything when you don’t commit transactions

The dry-run feature in MozApkPublisher, which just doesn’t commit the Google Play transaction, helps in detecting early failures. For instance: wrong version codes, wrong package names. Nevertheless, we have hit cases where dry runs went smoothly and we had to diagnose new issues at commit time.

User fractions can also be specified on other tracks (but that’s not a feature)

Fennec Release 53.0 is the first version which was entirely published via Taskcluster. Mozilla also uses the rollout track on Release only. Beta is pushed to the production one (and that is actually something we are reviewing). Sadly, there was another configuration error: even though, the user fraction was specified, the configured track was the production one. Google Play didn’t raise any error (even at commit time), starting a full-throttled release. At that time, I contacted the Google Play support, to ask if it was possible to switch back to rollout. The person was very courteous. He explained they were not able to perform that kind of action. This is why they transmitted my request to the tech team, who will follow up by email.

In parallel, we have fixed the configuration error and implemented our own check in MozApkPublisher.

There is no way to rollback to previous APKs, even if you ask a human

The previous configuration error could have remained brieve, if somebody didn’t report what seemed like an important crash, 1 hour later. At that point, the Release Management team wanted to stall updates, in order to not spread the regression too much. We were still waiting on the support’s answer, but I reached out to them again since our request became different. I told the new contact I had about the previous issue, the new one, and the fact we were running against the clock. Sadly for us, the person only gave us the option to wait on the email follow up.

About 16 hours later, we got the email with the official answer:

Unfortunately, we cannot remove the APK in question, neither can we claw back the APK from the users that have already installed this update.

If you want to stop further users from installing this APK, then you need to make another release that deactivates this APK and add the APK that you want users to install instead.

With that in mind, we have been thinking of another way to use Google Play, where the rollout track would be more extensively used.

What’s next? Want to contribute? & Special thanks

See the next post.

Comments

You can read and leave comments on this Github issue.

June 12, 2017 09:17 AM

June 07, 2017

Part 2: How Mozilla publishes APKs onto Google Play Store, in a reasonably secure and automated way

The Release Engineering team fully-automated the publication of Firefox for Android in version 53.0. Let’s see what was already there and how things have changed since version 53.0.

This blog post is a part of a serial. Checkout the other posts:

  1. How did the project start?
  2. Presentation of the solution [Here]
  3. 5 things I would have loved knowing about Google Play
  4. What’s next? Want to contribute? & Special thanks

Presentation of the solution

The needs

The solution

Based on Taskcluster

Mozilla, and more specifically the Release Engineering team, uses Taskcluster to implement the Firefox release workflow. The workflow can be summed up as:

  1. Build Firefox with all supported locales (languages)
  2. Sign these builds
  3. Publish them everywhere (on https://archive.mozilla.org/, on https://www.mozilla.org/firefox/, via updates, etc.)

Each step is defined by its own set of tasks. These tasks are processed by specialized workers (represented by worker types). Those workers basically run a script against parameters given in the task definition.

Therefore, publishing to Google Play was a matter of creating a new Taskcluster task, which will be processed by a dedicated script and executed by its own worker type.

With some extra-security features

The aforementioned script must be bootstrapped to be integrated to the rest of Taskcluster. There are several ways to bootstrap scripts for Taskcluster. One of them is to create a docker image which Taskcluster pulls and run.

However, because of the needs stated above, we decided to go with a security-focused framework: scriptworker. Scriptworker was initially created to perform one of the most critical operation security-wise: sign builds. The framework has some great interesting features:

How pieces are wired together
0. Overview

Here’s a general view of how things are wired together:

Architecture overview

1. Task creation

There are many ways to submit the definition of a task to Taskcluster. For example, you can:

Each of them was used at some point, but the ultimate solution relies on the last one. The taskgraph is a graph generator which, depending on given parameters, creates a graph of builds, tests and deployment tasks. Taskgraph generation is run on Taskcluster too, under what we commonly call “the decision task”. This solution benefits from being on hg.mozilla.org: it is versioned and only vouched people are able to modify it.

Moreover, taskgraph generates what is necessary for scriptworker to validate the task definitions and artifacts. To do so, taskgraph:

2. Scriptworker and new tasks

Scriptworker polls tasks from Taskcluster queue. That is actually one of the great things about Taskcluster: workers don’t have to open inbound (listening) ports. This reduces the potential surface of attack. Fetching new tasks is done via this bit of REST API which workers can poll. Speaking of which, workers are authenticated to Taskcluster, which prevents them from claiming a task that it isn’t meant to take.

Secure download of artifacts is done by the “Chain of Trust” feature of scriptworker. Once set up, if you define upstreamArtifacts within the task definition, scriptworker will:

  1. Make sure the current task and its dependencies have not changed since its definition. This is done by comparing the JSON the taskgraph generated and the actual definition.
  2. Check the signatures of every dependency, by looking at a special artifact Chain of Trust creates. This helps to verify no rogue worker processed a upstream task.
  3. Download artifacts on the worker and verify the checksums.

If all goes well, scriptworker will call pushapkscript

3. Pushapkscript and APKs

Here starts the Android-specific bits. Pushapkscript performs some extra checks on the APKs:

Pushapkscript knows about the location of the Google Play credentials (P12 certificates). It finally gives all the files (checked APKs and credentials) to MozApkPublisher.

4. MozApkPublisher, locales and Google Play

To be honest, MozApkPublisher could have been implemented within pushapkscript, but the split exists for historical reasons and still has a meaning today: this was the script Release Management used before this project got started. It also remains a way to let a human publish, in case of emergency.

It checks that APKs are multi-locale. We serve the same APK, which includes (almost) every locale in it. That’s a verification Google doesn’t do.

It also fetches the latest strings to display on the Play Store (like the localized descriptions). These strings are then posted on Google Play, alongside the APKs.

MozApkPublisher provides a dry-run mode thanks to the transaction mechanism exposed by Google’s API. Nothing is effectively published until the transaction is committed.

5. Pushapk_scriptworker: Scriptworker, Pushapkscript, and MozApkPublisher on the same machine

The 3 pieces live on the same Amazon EC2 instance, under the name pushapk_scriptworker. The configuration of this instance is managed by Puppet. The entire Puppet configuration is public on hg.mozilla.org, with the exception of secrets (Tascluster credentials, P12 certificates) which are encrypted on a seperate machine. Like the main Firefox repository, only vouched people can submit changes to the Puppet configuration.

5 things I would have loved knowing about Google Play

See the next post.

Comments

You can read and leave comments on this Github issue.

June 07, 2017 12:24 PM

June 06, 2017

Part 1: How Mozilla publishes APKs onto Google Play Store, in a reasonably secure and automated way

The Release Engineering team fully-automated the publication of Firefox for Android in version 53.0. Let’s see what was already there and how things have changed since version 53.0.

This blog post is a part of a serial. Checkout the other posts:

  1. How did the project start? [Here]
  2. Presentation of the solution
  3. 5 things I would have loved knowing about Google Play
  4. What’s next? Want to contribute? & Special thanks

How did the project start?

Mozilla ships Firefox every day

This is true for desktop (Windows, Linux, Mac) and Android. However, we don’t ship that often to every user. We have different channels, receiving updates at different frequencies:

About Firefox Aurora

You may have heard, Firefox Aurora has been discontinued in April 2017. Although, these blog posts will talk about it. The main reason is: Most of the experiments were done on Aurora, before it was stopped.

Today, the Android users who were on Aurora have been migrated to Nightly. New users are also given Nightly.

Why do we need Firefox for Android on app stores?

Unlike Firefox for desktop, Android apps have to be uploaded onto application stores (like Google Play Store). Otherwise, they have very low visibility. For instance, Firefox for Android Aurora (codenamed “Fennec Aurora”) was not on Google Play until September 2016, but it was downloadable from our official website (now redirected to Nightly). After we started publishing Aurora on Google Play, we increased our number of users by 5x.

Why are we automating the publication today?

Google didn’t offer a way to script a publication on Play Store, before July 2014. It had to be done manually, from their website. Around that time, a few people from Release Management implemented a first script. One person from the Release Management team ran it every time Beta or Release was ready, from his/her own machine. With Aurora being out, we now have several APKs (one per processor architecture/Android API level, which translates to 2 at the moment: one for x86 processors, the other for ARM) to publish each day.

The daily frequency was new for Fennec. It led to 2 concerns:

  1. A human has to repeat the same task every day.
  2. Pushing every day from a workstation increases the surface of security threats.

That is why we decided to make APK publication a part of the automated release workflow.

Presentation of the solution

See the next post.

Comments

You can read and leave comments on this Github issue.

June 06, 2017 01:25 PM

May 17, 2017

Kim Moir (kmoir)

New blog location

I moved my blog to WordPress.

New location is here https://kimmoir.blog/

May 17, 2017 09:12 PM

March 13, 2017

Chris Cooper (coop)

Shameless self (release) promotion: Firefox 53.0b1 from TaskCluster

You may recall two short months ago when we moved Linux and Android nightlies from buildbot to TaskCluster. Due to the train model, this put us (release engineering) on a clock: either we’d be ready to release a beta version of Firefox 53 for Linux and Android using release promotion in TaskCluster, or we’d need to hold back our work for at least the next cycle, causing uplift headaches galore.

I’m happy to report that we were able to successfully release Firefox 53.0b1 for Linux and Android from TaskCluster last week. This is impressive for 3 reasons:

  1. Mac and Windows builds were still promoted from buildbot, so we were able to seamlessly integrate the artifacts of two different continuous integration (CI) platforms.
  2. The process whereby nightly builds are generated has always been different from how we generate release builds. Firefox 53.0b1 represents the first time a beta build was generated using the same taskgraph we use for a nightly, thereby reducing the delta between CI builds and release builds. More work to be done here, for sure.
  3. Nobody noticed. With all the changes under the hood, this may be the most impressive achievement of all.

A round of thanks to Aki, Johan, Kim, and Mihai who worked hard to get the pieces in place for Android, and a special shout-out to Rail who handled the Linux beta while also dealing with the uplift requirements for ESR52. Of course, thanks to everyone else who has helped with the migration thus far. All of that foundational work is starting to pay off.

Much more to do, but I look forward to updating you about Mac and Windows progress soon.

March 13, 2017 07:17 PM

January 20, 2017

Chris AtLee (catlee)

Nightly builds from Taskcluster

Yesterday, for the very first time, we started shipping Linux Desktop and Android Firefox nightly builds from Taskcluster.

74851712.jpg

We now have a much more secure, resilient, and hackable nightly build and release process.

It's more secure, because we have developed a chain of trust that allows us to verify all generated artifacts back to the original decision task and docker image. Signing is no longer done as part of the build process, but is now split out into a discrete task after the build completes.

The new process is more resilient because we've split up the monolithic build process into smaller bits: build, signing, symbol upload, upload to CDN, and publishing updates are all done as separate tasks. If any one of these fail, they can be retried independently. We don't have to re-compile the entire build again just because an external service was temporarily unavailable.

Finally, it's more hackable - in a good way! All the configuration files for the nightly build and release process are contained in-tree. That means it's easier to inspect and change how nightly builds are done. Changes will automatically ride the trains to aurora, beta, etc.

Ideally you didn't even notice this change! We try and get these changes done quietly, smoothly, in the background.

This is a giant milestone for Mozilla's Release Engineering and Taskcluster teams, and is the result of many months of hard work, planning, coding, reviewing and debugging.

Big big thanks to jlund, Callek, mtabara, kmoir, aki, dustin, sfraser, jlorenzo, coop, jmaher, bstack, gbrown, and everybody else who made this possible!

January 20, 2017 01:35 PM

December 28, 2016

Chris AtLee (catlee)

2016 RelEng Retrospective

As 2016 winds down, I wanted to take some time to highlight all the work our Release Engineering team has done this year. Personally, I really enjoy writing these retrospective posts. I think it's good to spend some time remembering how far we've come in a year. It's really easy to forget what you did last month, and 6 months ago seems like ancient history!

People!

We added four people to our team this year!

Aki (:aki) re-joined us in January and has been working hard on developing a security model for Taskcluster for sensitive tasks like signing and publishing binaries.

Rok (:garbas) started in February and has been working on modernizing our web application framework development and deployment processes.

Johan (:jlorenzo) started in August and has been improving our release automation, Balrog, and automatically publishing Android builds to the Google Play Store.

Simon (:sfraser) started in October and has been improving monitoring of our production systems, as well as getting his feet wet with our partial update generation system.

Releases

This year we released 104 desktop versions of Firefox, and 58 android versions (including Beta, Release and ESR branches).

5 of those releases were just in the week prior to our all hands meeting in Hawaii!

Several other releases this year were special for particular reasons, and required special efforts on our part. We continued to provide SHA-1 signed installers for Windows XP users. We also produced a special 47.0.2 release in order to try and rescue users stuck on 47. We've never shipped a point release for a previous release branch before! We've also generated partial updates to try and help users on 43.0.1 and 47.0.2 get faster updates to the latest version of Firefox.

Release promotion

We couldn't have shipped so many releases so quickly last week if it weren't for release promotion. Previous to Firefox 46, our release process would generate completely new builds after CI was finished. This wasted a lot of time, and also meant we weren't shipping the exact binaries we had tested. Today, we ship the same builds that CI has generated and tested. This saves a ton of time (up to 8 hours!), and gives us a lot more confidence in the quality of the release.

This is one of those major kinds of changes that really transforms how we approach doing releases. I can't really remember what it was like doing releases prior to release promotion!

We also added support in Shipit to allow starting a release before all the en-US builds are done. This lets our Release Management team kick off a release early, assuming all the builds pass. It saves a person having to wait around watching Treeherder for the coveted green builds.

Windows in AWS

This year we completed our migration to AWS for Windows builds. 100% of our Windows builds are now done in AWS. This means that we now have a much faster and more scalable Windows build platform.

In addition, we also migrated most of the Windows 7 unittests to run in AWS. Previously these were running on dedicated hardware in our datacentre. By moving these tests to AWS, we again get a much more scalable test platform, but we also freed up hardware capacity for other test platforms (e.g. Windows XP).

Taskcluster

One of our major focus areas this year was migrating our infrastructure from Buildbot to Taskcluster. As of today, we have:

  • Fully migrated Linux64 and Android debug builds and tests
  • Builds for all other platforms operating as Tier2
  • Linux64 and Android nightly builds, l10n repacks and updates operating as Tier2
  • Tons of security design & implementation work

Balrog

Scheduled Changes in Balrog means that now we can have machines set background update rate to 0% 24 hours after release, instead of having a human do it.

Balrog itself was migrated from our datacentre in SCL3 into AWS. We now have a much more flexible deployment pipeline.

Balrog has also been one of our best projects for getting volunteer contributions! Many of the work done this year was done by contributors!

RIP

Being able to shut off old, crufty and deprecated stuff is an important part of staying agile. This year we were finally able to develop an end of life plan for Windows XP. In addition, we discontinued support for OSX 10.6-10.8, systems without SSE2, and 32-bit OSX systems. Not having to support these old platforms simplifies managing our infrastructure, and also makes product development easier.

We also shut down all the panda mobile testing infrastructure and legacy vcs-sync.

What's next?

2017 is looking like it's going to be another interesting (and busy!) year for RelEng.

Our top priority is to finish the migration to Taskcluster. Hopefully by the end of 2017, the only thing left on buildbot will be the ESR52 branch. This will require some big changes to our release automation, especially for Fennec.

We're also planning to provide some automated processes to assist with the rest of the release process. Releases still involve a lot of human to human handoffs, and places where humans are responsible for triggering automation. We'd like to provide a platform to be able to manage these handoffs more reliably, and allow different pieces of automation to coordinate more effectively.

December 28, 2016 07:35 PM

September 30, 2016

Kim Moir (kmoir)

Beyond the Code 2016 recap

I've had the opportunity to attend the Beyond the Code conference for the past two years.  This year, the venue moved to a location in Toronto, the last two events had been held in Ottawa.  The conference is organized by Shopify who again managed to have a really great speaker line up this year on a variety of interesting topics.  It was a two track conference so I'll summarize some of the talks I attended.  

The conference started off with Anna Lambert of Shopify welcoming everyone to the conference.





The first speaker was Atlee Clark, Director of App and Developer relations at Shopify who discussed the wheel of diversity.


The wheel of diversity is a way of mapping the characteristics that you're born with (age, gender, gender expression, race or ethnicity, national origin, mental/physical ability), along with those that you acquire through life (appearance, education, political belief, religion, income, language and communication skills, work experience, family,  organizational role).  When you look at your team, you can map how diverse it is by colour.  (Of course, some of these characteristics are personal and might not be shared with others).  You can see how diverse the team is by mapping different characteristics with different colours.  If you map your team and it's mostly the same colour, then you probably will not bring different perspectives together when you work because you all have similar backgrounds and life experiences.  This is especially important when developing products. 



This wheel also applies to hiring too.  You want to have different perspectives when you're interviewing someone.  Atlee mentioned when she was hiring for a new role, she mapped out the characteristics of the people who would be conducting the hiring interviews and found there was a lot of yellow.


So she switched up the team that would be conducting the interviews to include people with more diverse perspectives.

She finished by stating that this is just a tool, keep it simple, and practice makes it better. 

The next talk was by Erica Joy, who is a build and release engineer at Slack, as well as a diversity advocate.  I have to admit, when I saw she was going to speak at Beyond the Code, I immediately pulled out my credit card and purchased a conference ticket.  She is one of my tech heroes.  Not only did she build the build and release pipeline at Slack from the ground up, she is an amazing writer and advocate for change in the tech industry.   I highly recommend reading everything she has written on Medium, her chapter in Lean Out and all her discussions on twitter.  So fantastic.

Her talk at the conference was "Building a Diverse Corporate Culture: Diversity and Inclusion in Tech".  She talked about how literally thousands of companies say they value inclusion and diversity.  However, few talk about what they are willing to give up to order to achieve it.  Are you willing to give up your window seat with a great view?   Something else so that others can be paid fairly?  She mentioned that change is never free.  People need both mentorship and sponsorship in in order to progress in their career.





I really liked her discussion around hiring and referrals.  She stated that when you're hire people you already know you're probably excluding equally or better qualified that you don't know.  By default, women of colour are underpaid.

Pay gap for white woman, African American women and Hispanic women compared to a white man in the United States.

Some companies have referral system to give larger referral bonuses to people who are underrepresented in tech, she gave the example of Intel which has this in place.  This is a way to incentivize your referral system so you don't just hire all your white friends.  

The average white American has 91 white friends and one black friend so it's not very likely that they will refer non-white people. Not sure what the numbers are like in Canada but I'd guess that they are quite similar.
  
In addition, don't ask people to work for free, to speak at conferences or do diversity and inclusion work.  Her words were "We can't pay rent with exposure".

Spend time talking to diversity and inclusion experts.  There are people that have spent their entire lives conducting research in this area and you can learn from their expertise.  Meritocracy is a myth, we are just lucky to be in the right place in the right time.  She mentioned that her colleague Duretti Hirpa at Slack points out the need for accomplices, not allies. People that will actually speak up for others.  So people feeling pain or facing a difficult work environment don't have to do all the work of fighting for change. 




In most companies, there aren't escalation paths for human issues either.  If a person is making sexist or racist remarks, shouldn't that be a firing offense? 

If people were really working hard on diversity and inclusion, we would see more women and people of colour on boards and in leadership positions.  But we don't.

She closed with a quote from Beyonce:

"If everything was perfect, you would never learn and you would never grow"

💜💜💜

The next talk I attended was by Coraline Ada Ehmke, who is an application engineer at Github.  Her talk was about the "Broken Promise of Open Source".  Open source has the core principals of the free exchange of ideas, success through collaboration, shared ownership and meritocracy.


However, meritocracy is a myth.  Currently, only 6% of Github users are women.  The environment can be toxic, which drives a lot of people away.  She mentioned that we don't have numbers for diversity in open source other than women, but Github plans to do a survey soon to try to acquire more data.


Gabriel Fayant from Assembly of Seven Generation's talk was entitled "Walking in Both Worlds, traditional ways of being and the world of technology".  I found this quite interesting, she talked about traditional ceremonies and how they promote the idea of living in the moment, and thus looking at your phone during a drum ceremony isn't living the full experience.  A question from the audience from someone who worked in the engineering faculty at the University of Toronto was how we can work with indigenous communities to share our knowledge of the technology and make youth both producers of tech, not just consumers. 

If everything was perfect, you would never learn and you would never grow.
Read more at: http://www.brainyquote.com/quotes/quotes/b/beyoncekno596349.html

f everything was perfect, you would never learn and you would never grow.
Read more at: http://www.brainyquote.com/quotes/quotes/b/beyoncekno596349.html
The next talk was by Sandi Metz, entitled "Madame Santi tells your future".  This was a totally fascinating look at the history of printing text from scrolls all the way to computers.

She gave the same talk at another conference earlier so you watch it here.  It described the progression of printing technology from 7000 years ago until today.  Each new technology disrupted the previous one, and it was difficult for those who worked on the previous technology to make the jump to work on the new one. 

So according to Sandi, what is your future?

The last talk I attended was by Sabrina Geremia of Google Canada.  She talked about the factors that encourage a girl to consider computer science (encouragement, career perception, self-perception and academic exposure.)


I found that this talk was interesting but it focused a bit too much on the pipeline argument - that the major problem is that girls are not enrolling in CS courses.  If you look at all the problems with environment, culture, lack of pay equity and opportunities for promotion due to bias, maybe choosing a career where there is more diversity is a better choice.  For instance, law, accounting and medicine have much better numbers for these issues, despite there still being an imbalance.

At the end of the day, there was a panel to discuss diversity issues:

Moderator: Ariti Sharma, Shopify, Panelists: Mohammed Asaduallah, Format, Katie Krepps, Capital One Canada, Lateesha Thomas, Dev Bootcamp, Ramya Raghavan, Google, Kara Melton, TWG, Gladstone Grant, Microsoft Canada
Some of my notes from the panel

Compared to the previous two iterations of this conference, it seemed that this time it focused a lot more on solutions to have more diversity and inclusion in your company. The previous two conferences I attended seemed to focus more on technical talks by diverse speakers.


As a side note, there were a lot of Shopify folks in attendance because they ran the conference.  They sent a bus of people from their head office in Ottawa to attend it.  I was really struck at how diverse some of the teams were.  I met group of women who described themselves as a team of "five badass women developers" 💯 As someone who has been the only woman on her team for most of her career, this was beautiful to see and gave me hope for the future of our industry.   I've visited the Ottawa Shopify office several times (Mr. Releng works there) and I know that the representation of of their office doesn't match the demographics of the Beyond the Code attendees which tended to be more women and people of colour.  But still, it is refreshing to see a company making a real effort to make their culture inclusive.  I've read that it is easier to make your culture inclusive from the start, rather than trying to make difficult culture changes years later when your teams are all homogeneous. So kudos to them for setting an example for other companies.

Thank you Shopify for organizing this conference, I learned a lot and I look forward to the next one!

September 30, 2016 01:10 PM

July 29, 2016

Kim Moir (kmoir)

Ottawa Python Authors Meetup: Artificial Intelligence with Python

Last night, I attended my first Ottawa Python Authors Meetup.  It was the first time that I had attended despite wanting to attend for a long time.  (Mr. Releng also works with Python and thus every time there's a meetup, we discuss who gets to go and who gets to stay home and take care of little Releng.  It depends on if the talk to more relevant to our work interests.)

The venue was across the street from Confederation Park aka land of Pokemon.


I really enjoyed it.  The people I chatted with were very friendly and welcoming. Of course, I ran into some people I used to work with, as is with any tech event in Ottawa it seems. Nice to catch up!

The venue had the Canada Council for the Arts as a tenant, thus the quintessentially Canadian art.


The speaker that night was Emily Daniels, developer from Halogen Software who spoke on Artificial Intelligence with Python. (Slides here, github repo here).  She mentioned that she writes Java during the day but works on fun projects in Python at night.  She started the talk by going through some examples of artificial intelligence on the web.  Perhaps the most interesting one I found was a recurrent neural network called Benjamin which generates movie script ideas and was trained on existing sci-fi movies and movie scripts.  Also, a short film called Sunspring was made of one of the generated scripts.  The dialogue is kind of stilted but it is interesting concept.

 After the examples, Emily then moved on to how it all works. 

Deep learning is a type of machine learning that drives meaning out of data using a hierarchy of multiple layers that mimics the neural networks of our brain.

She then spoke about a project she wrote to create generative poetry from a RNN (recurrent neural network).  It was based on a RNN tutorial that she heavily refactored to meet her needs.  She went through the code that she developed to generate artificial prose from the works of H.G. Wells and Jane Austen.  She talked about how she cleaned up the text to remove EOL delimiters, page breaks, chapters numbers and so on. And then it took a week to train it with the data.

She then talked about another example which used data from Jack Kerouac and Virginia Woolf novels, which she posts some of the results to twitter.


She also created a twitter account which posts generated text from her RNN that consumes the content of Walt Whitman and Emily Dickinson. (I should mention at this point that she chose these authors for her projects because copyrights have expired on these works and they are available on the Gutenberg project)

After the talk, she field a number of audience questions which were really insightful. There were discussions on the inherent bias in the data because it was written by humans that are sexist and racist.  She mentioned that she doesn't post the results of the model automatically to twitter because some of them are really inappropriate since these novels since they learned from text that humans wrote who are inherently biased.

One thing I found really interesting is that Emily mentioned that she felt a need to ensure that the algorithms and data continue to exist, and that they were faithfully backed up.  I began to think about all the Amazon instances that Mozilla releng had automatically killed that day as our capacity had peaked and declined.  And of the great joy I feel ripping out code when we deprecate a platform.  I personally feel no emotional attachment to bring down machines or deleting used code.
 
Perhaps the sense of a need for a caretaker for these recurrent neural networks and the data they create is related to the fact that the algorithms that output text that is a simulacrum for the work of an author that we enjoy reading.  And perhaps that is why we maybe we aren't as attached to a ephemeral pool of build machines as we are are to our phones.  Because the phone provides a sense human of connection to the larger world when we may be sitting alone.

Thank you Emily for the very interesting talk, to the Ottawa Python Authors Group for organizing the meetup, and Shopify for sponsoring the venue.  Looking forward to the next one!

Further reading

July 29, 2016 07:31 PM

Eclipse Committer Emeritus

I received this very kind email in my inbox this morning.

"David Williams has expired your commit rights to the
eclipse.platform.releng project.  The reason for this change is:

We have all known this day would come, but it does not make it any easier.
It has taken me four years to accept that Kim is no longer helping us with
Eclipse. That is how large her impact was, both on myself and Eclipse as a
whole. And that is just the beginning of why I am designating her as
"Committer Emeritus". Without her, I humbly suggest that Eclipse would not
have gone very far. Git shows her active from 2003 to 2012 -- longer than
most! She is (still!) user number one on the build machine. (In Unix terms,
that is UID 500). The original admin, when "Eclipse" was just the Eclipse
Project.

She was not only dedicated to her job as a release engineer she was
passionate about doing all she could to make other committer's jobs easier
so they could focus on their code and specialties. She did (and still does)
know that release engineering is a field of its own; a specialized
profession (not something to "tack on" at the end) that just anyone can do)
 and good, committed release engineers are critical to the success of any
project.

For anyone reading this that did not know Kim, it is not too late: you can
follow her blog at

http://relengofthenerds.blogspot.com/

You will see that she is still passionate about release engineering and
influential in her field.

And, besides all that, she was (I assume still is :) a well-rounded, nice
person, that was easy to work with! (Well, except she likes running for
exercise. :)

Thanks, Kim, for all that you gave to Eclipse and my personal thanks for
all that you taught me over the years (and I mean before I even tried to
fill your shoes in the Platform).

We all appreciate your enormous contribution to the success of Eclipse and
happy to see your successes continuing.

To honor your contributions to the project, David Williams has nominated
you for Committer Emeritus status."


Thank you David! I really appreciate your kind words.  I learned so much working with everyone in the Eclipse community.  I had the intention to contribute to Eclipse when I left IBM but really felt that I have given all I had to give.  Few people have the chance to contribute to two fantastic open source communities during their career.  I'm lucky to have that opportunity.


My IBM friends made this neat Eclipse poster when I left.  The Mozilla dino displays my IRC handle.

July 29, 2016 07:06 PM

July 12, 2016

Rail Alliev (rail)

Thoughts about partial updates on demand

Firefox has it's own built-in update system. The update system supports 2 types of updates: complete and incremental. Completes can be applied to any older version, unless there are some incompatible changes in the MAR format. Incremental updates can be applied only to a release they were generated for.

Usually for the beta and release channels we generate incremental updates against 3-4 versions. This way we try to minimize bandwidth consumption for our end users and increase the number of users on the latest version. For Nightly and Developer Edition builds we generate 5 incremental updates using funsize.

Both methods assume that we know ahead of time what versions should be used for incremental updates. For releases and betas we use ADI stats to be as precise as possible. However, these methods are static and don't use real-time data.

The idea to generate incremental updates on demand has been around for ages. Some of the challenges are:

  • Acquiring real-time (or close to real-time) data for making decisions on incremental update versions

  • Size of the incremental updates. If the size is very close to the size of the corresponding complete, there is reason to serve incremental updates. One of the reasons is that the that the updater tries to use the incremental update first, and then falls back to the complete in case if something goes wrong. In this case the updater downloads both the incremental and the complete.

Ben and I talked about this today and to recap some of the ideas we had, I'll put them here.

  • We still want to "pre-seed" most possible incremental updates before we publish any updates

  • Whenever Balrog serves a complete-only update, it should generate a structured log entry and/or an event to be consumed by some service, which should contain all information required to generate a incremental update.

  • The "new system" should be able to decide if we want to discard incremental update generation, based on the size. These decisions should be stored, so we don't try to generate incremental update again next time. This information may be stored in Balrog to prevent further events/logs.

  • Before publishing the incremental update, we should test if they can be applied without issues, similar to the update verify tests we run for releases, but without hitting Balrog. After they pass this test, we can publish them to Balrog and check if Balrog returns expected XML with partial info in it.

  • Minimize the amount of served completes, if we plan to generate incremental updates. One of the ideas was to modify the client to support responses like "Come in 5 minutes, I may have something for you!"

The only remaining thing is to implement all these changes. :)

July 12, 2016 07:03 PM

June 07, 2016

Kim Moir (kmoir)

Submissions for Releng 2016: due by July 1, 2016

The CFP for Releng 2016 is open!  The workshop will be held November 18, 2016 in Seattle.  It will be held in conjunction with FSE 2016.  (Foundations of Software Engineering ACM conference)
Picture by howardignatius- Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)
https://www.flickr.com/photos/howardignatius/14482954049/sizes/l
If you've done something like

We'd like to encourage people new to speaking to apply, as well as those from underrepresented groups in tech. We'd love to hear from some new voices and new companies ! 


Submissions are due July 1, 2016. If you have questions on of the submission process, topics to submit, or anything else, I'm happy to help!  I'm kmoir and I work at mozilla.com or contact me on twitter. Submit early and often!

June 07, 2016 12:59 AM

June 03, 2016

Kim Moir (kmoir)

DevOpsDays Toronto recap

Last week I attended DevOpsDays Toronto.  It was my first time attending a DevOpsDays event and it was quite interesting.  It was held at CBC's Glenn Gould studios which is a quick walk from the Toronto Island airport where I landed after an hour flight from Ottawa.  This blog post is an overview of some of the talks at the conference.
 
Glenn Gould Studios, CBC, Toronto.  

Statue of Glenn Gould outside the CBC studios that bear his name.

Day 1


The day started out with an introduction from the organizers and a brief overview of history of DevOps days. They also made a point about reminding everyone that they had agreed to the code of conduct when they bought their ticket. I found this explicit mention of the code of conduct quite refreshing.


The first talk of the day was John Willis,  evangelist at Docker.  He gave an overview of the state of enterprise devops. I found this a fresh perspective because I really don't know what happens in enterprises with respect to DevOps since I have been working in open source communities for so long.  John providing an overview of what DevOps encompasses.


DevOps is a continuous feedback loop.


He talked a lot about how empathy is so important in our jobs.  He mentions that at Netflix has a slide deck that describes company culture.  He doesn't know if this is still the case, but it he had heard that if you hadn't read the company culture deck and show up for an interview at Netflix, you would be automatically disqualified for further interviews.  Etsy and Spotify have similar open documents describing their culture.

Here he discusses the research by Christina Maslach on the six sources of burnout.
Christina Maslach
Christina Maslach

He gave us some reading to do.  I've read the "Release It!" book which is excellent and has some fascinating stories of software failure in it, I've added the other books to my already long reading list.

The rugged manifesto and realizing that the code you write will always be under attack by malicious authors.  ICE stands for Inclusivity, Complexity and Empathy.

He stated that it's a long standing mantra that you can have two of either fast, cheap or good but recent research shows that today we can many changes quickly, and if there is a failure the mean time to recovery is short.

He left us with some more books to read.

The second talk was a really interesting talk by Hany Fahim, CEO of VM Farms.  It was a short mystery novella describing how VM Farms servers suddenly experienced a huge traffic spike when the Brazilian government banned Whatsapp  as a result of a legal order. I love a good war story.

 Hany discussed one day VMfarms suddenly saw a huge increase in traffic. 

This was a really important point.  When your system is failing to scale, it's important to decide if it's a valid increase in traffic or malicious.


Looking on twitter, they found that a court case in Brazil had recently ruled that Whatsup would be blocked for 48 hours.  Users started circumventing this block via VPN.  Looking at their logs, they determined that most of the traffic was resolving to ip addresses from Brazil and  that there was a large connection time during SSL handshakes.
  

The government of Brazil encouraged the use of open source software versus Windows, and thus the users became more technically literate, and able to circumvent blocks via VPN.


In conclusion, making changes to use multi-core HAProxy fixed a lot of issues. Also, twitter was and continues to be a great source of information on activity that is happening in other countries. Whatsapp was returned to service and then banned a second time, and their servers were able to keep up with the demand.

After lunch, we were back to to more talks.  The organizers came on stage for a while to discuss the afternoon's agenda.  They also remarked that one individual had violated the code of conduct and had been removed from the conference.  So, the conference had a code of conduct and steps were taken if it was violated.

Next up, Bridget Kromhout from Pivotal gave a talk entitled Containers will not Fix your Broken Culture.
I first saw Bridget speak at Beyond the Code in Ottawa in 2014 about scaling the streaming services for Drama Fever on AWS.  At the time, I was moving our mobile test infrastructure to AWS so I was quite enthralled with her talk because 1) it was excellent 2) I had never seen another woman give a talk about scaling services on AWS.  Representation matters.

The summary of the talk last week was that no matter what tools you adopt, you need to communicate with each other about the cultural changes are required to implement new services.  A new microservices architecture is great, but if these teams that are implementing these services are not talking to each other, the implementation will not succeed.

Bridget pointing out that the technology we choose to implement is often about what is fashionable.


Shoutout to Jennifer Davis' and Katherine Daniel's Effective DevOps book. (note -  I've read it on Safari online and it is excellent.  The chapter on hiring is especially good)

Loved this poster about the wall of confusion between development and operations.  

In the afternoon, there were were lightning talks and then open spaces. Open spaces are free flowing discussions where the topic is voted upon ahead of time.  I attended ones on infrastructure automation, CI/CD at scale and my personal favourite, horror stories.  I do love hearing how distributed system can go down and how to recover.  I found that the conversations were useful but it seemed like some of them were dominated by a few voices.  I think it would be better if the person that suggested to topic for the open space also volunteered to moderate the discussion.

Day 2

The second day started out with a fantastic talk by John Arthorne of Shopify speaking on scaling their deployment pipeline.  As a side note, John and I worked together for more than a decade on Eclipse while we both worked at IBM so it was great to catch up with him after the talk. 



He started by giving some key platform characteristics.  Stores on Shopify have flash sales that have traffic spikes so they need to be able to scale for these bursts of traffic. 

From commit to deploy in 10 minutes.  Everyone can deploy. This has two purposes: Make sure the developer stays involved in the deploy process.  If it only takes 10 minutes, they can watch to make sure that their deploy succeeds. If it takes longer, they might move on to another task.  Another advantage of this quick deploy process is that it can delight customers with the speed of deployment.  They also deploy in small batches to ensure that the mean time to recover is small if the change needs to be rolled back.
 
BuildKite is a third party build and test orchestration service.  They wrote a tool called Scrooge that monitors the number of EC2 nodes based on current demand to reduce their AWS bills.  (Similar to what Mozilla releng does with cloud-tools)


Shopify uses a open source orchestration tool called ShipIt.  I was sitting next to my colleague Armen at the conference and he started chuckling at this point because at Mozilla we also wrote an application called ship-it which release management uses to kick off Firefox releases.   Shopify also has a overall view of the ship it deployment process which allows developers to see the percentages of nodes where their change has been deployed. One of the questions after the talk was why they use AWS for their deployment pipeline when they have use machines in data centres for their actual customers. Answer: They use AWS where resilency is not an issue. 
 
Building containers is computationally expensive. He noted that a lot of engineering resources went into optimizing the layers in the Docker containers. To isolate changes to the smallest layer.  They build service called Locutus to build the containers on commit, and push to a registry. It employs caching to make the builds smaller. 

One key point that John also mentioned is that they had a team dedicated to optimizing their deployment pipeline.  It is unreasonable to expect that developers working on the core Shopify platform to also optimize the pipeline.

In the afternoon , there were a series of lightning talks. Roderick Randolph from Capital One gave an amazing talk about Supporting Developers through DevOps.


It was an interesting perspective.  I've seen quite a few talks about bringing devops culture and practices to the operations side of the house, but the perspective of teaching developers about it is discussed less often.



He emphasized the need to empower developers to use DevOp practices by giving them tools, and showing them how to use them.  For instance, if they needed to run docker to test something, walk them through it so they will know how to do it next time. 





The final talk I'll mention is by Will Weaver.  He talks about how it is hard to show prospective clients how he had CI and tests experience when that experience is not open to the public.  So he implemented tests and CI for his dotfiles on github. 


He had excellent advice on how to work on projects outside of work to showcase skills for future employers.




Diversity and Inclusion


As an aside, whenever I'm at a conference I note the number of people in the "not a white guy" group. This conference had an all men organizing committee but not all white men.  (I recognize the fact that not all diversity is visible i.e. mental health, gender identity, sexual orientation, immigration status etc) They was only one woman speaker, but there were a few non-white speakers.  There were very few women attendees. I'm not sure what the process was to reach out to potential speakers other than the CFP. 



 There were slides that showed diverse developers which was refreshing.



Loved Roderick's ops vs dev slide.

I learned a lot at the conference and am thankful for all the time that the speakers took to prepare their talks.  I enjoyed all the conversations I had learning about the challenges people face in the organizations implementing continuous integration and deployment. It also made me appreciate the culture of relentless automation, continuous integration and deployment that we have at Mozilla.

I don't know who said this during the conference but I really liked it

Shipping is the heartbeat of your company

It was interesting to learn how all these people are making their companies heart beat stronger via DevOps practices and tools.

June 03, 2016 05:39 PM

May 13, 2016

Kim Moir (kmoir)

Welcome Mozilla Releng summer interns

We're delighted to have Francis Kang and Connor Sheehan join the Mozilla release engineering team as summer interns.  Francis is studying at the University of Toronto while Connor attends McMaster University in Hamilton, Ontario.  We'll have another intern (Anthony) join us later on in the summer who will be working from our San Francisco office.

Francis and Connor will be working on implementing some new features in release promotion as well as  migrating some builds to taskcluster.  I'll be mentoring Francis,  while Rail will be mentoring Connor.  If you are in the Toronto office, please drop by to say hi to them.  Or welcome them on irc as fkang or sheehan. 

Kim, Francis, Connor and Rail
They are both already off to a great start and have pull requests merged into production that fixed some release promotion issues.  Their code was used in the Firefox 47.0 beta 5 release promotion that we ran last night so their first week was quite productive.


Mentoring an intern provides an opportunity to see the systems we run from a fresh perspective.  They both have lots of great questions which makes us revisit why design decisions were made, could we do things better?   Like all teaching roles, I always find that I learn a tremendous amount from the experience, and hope they have fun learning real world software engineering concepts with respect to running large distributed systems.

Welcome to Mozilla!

May 13, 2016 03:20 PM

April 27, 2016

Rail Alliev (rail)

Firefox 46.0 and SHA512SUMS

In my previous post I introduced the new release process we have been adopting in the 46.0 release cycle.

Release build promotion has been in production since Firefox 46.0 Beta 1. We have discovered some minor issues; some of them are already fixed, some still waiting.

One of the visible bugs is Bug 1260892. We generate a big SHA512SUMS file, which should contain all important checksums. With numerous changes to the process the file doesn't represent all required files anymore. Some files are missing, some have different names.

We are working on fixing the bug, but you can use the following work around to verify the files.

For example, if you want to verify http://ftp.mozilla.org/pub/firefox/releases/46.0/win64/ach/Firefox%20Setup%2046.0.exe, you need use the following 2 files:

http://ftp.mozilla.org/pub/firefox/candidates/46.0-candidates/build5/win64/ach/firefox-46.0.checksums

http://ftp.mozilla.org/pub/firefox/candidates/46.0-candidates/build5/win64/ach/firefox-46.0.checksums.asc

Example commands:

# download all required files
$ wget -q http://ftp.mozilla.org/pub/firefox/releases/46.0/win64/ach/Firefox%20Setup%2046.0.exe
$ wget -q http://ftp.mozilla.org/pub/firefox/candidates/46.0-candidates/build5/win64/ach/firefox-46.0.checksums
$ wget -q http://ftp.mozilla.org/pub/firefox/candidates/46.0-candidates/build5/win64/ach/firefox-46.0.checksums.asc
$ wget -q http://ftp.mozilla.org/pub/firefox/releases/46.0/KEY
# Import Mozilla Releng key into a temporary GPG directory
$ mkdir .tmp-gpg-home && chmod 700 .tmp-gpg-home
$ gpg --homedir .tmp-gpg-home --import KEY
# verify the signature of the checksums file
$ gpg --homedir .tmp-gpg-home --verify firefox-46.0.checksums.asc && echo "OK" || echo "Not OK"
# calculate the SHA512 checksum of the file
$ sha512sum "Firefox Setup 46.0.exe"
c2ed64298ac2140d8dbdaed28cabc90b38dd9444e9c0d6dd335a2a32cf043a35314945536a5c75124a88bf418a4e2ba77256be223425380e7fcc45a97da8f479  Firefox Setup 46.0.exe
# lookup for the checksum in the checksums file
$ grep c2ed64298ac2140d8dbdaed28cabc90b38dd9444e9c0d6dd335a2a32cf043a35314945536a5c75124a88bf418a4e2ba77256be223425380e7fcc45a97da8f479 firefox-46.0.checksums
c2ed64298ac2140d8dbdaed28cabc90b38dd9444e9c0d6dd335a2a32cf043a35314945536a5c75124a88bf418a4e2ba77256be223425380e7fcc45a97da8f479 sha512 46275456 install/sea/firefox-46.0.ach.win64.installer.exe

This is just a temporary work around and the bug will be fixed ASAP.

April 27, 2016 04:47 PM

April 05, 2016

Rail Alliev (rail)

Release Build Promotion Overview

Hello from Release Engineering! Once a month we highlight one of our projects to help the Mozilla community discover a useful tool or an interesting contribution opportunity. This month's project is Release Build Promotion.

What is Release Build Promotion?

Release build promotion (or "build promotion", or "release promotion" for short), is the latest release pipeline for Firefox being developed by Release Engineering at Mozilla.

Release build promotion starts with the builds produced and tested by CI (e.g. on mozilla-beta or mozilla-release). We take these builds, and use them as the basis to generate all our l10n repacks, partial updates, etc. that are required to release Firefox. We "promote" the CI builds to the release channel.

How is this different?

The previous release pipeline also started with builds produced and tested by CI. However, when it came time to do a release, we would create an entirely new set of builds with slightly different build configuration. These builds would not get the regular CI testing.

Release build promotion improves the process by removing the second set of builds. This drastically improves the total time to do a release, and also increases our confidence in our products since we now are shipping exactly what's been tested. We also improve visibility of the release process; all the tasks that make up the release are now reported to Treeherder along with the corresponding CI builds.

Current status

Release build promotion is in use for Firefox desktop starting with the 46 beta cycle. ESR and release branches have not yet been switched over.

Firefox for Android is also not yet handled. We plan to have this ready for Firefox 47.

Some figures

One of the major reasons of this project was our release end-to-end times. I pulled some data to compare:

  • One of the Firefox 45 betas took almost 12 hours

  • One of the Firefox 46 betas took less than 3 hours

What's next?

  • Support Firefox for Android

  • Support release and ESR branches

  • Extend this process back to the aurora and nightly channels

Can I contribute?

Yes! We still have a lot of things to do and welcome everyone to contribute.

  • Bug 1253369 - Notifications on release promotion events.

  • (No bug yet) Redesign and modernize Ship-it to reflect the new release work flow. This will include new UI, multiple sign-offs, new release-runner, etc.

  • Tracking bug

More information

For more information, please refer to these other resources about build promotion:

There will be multiple blog posts regarding this project. You have probably seen Jordan's blog on how to be productive when distributed teams get together. It covers some of our experience we had during the project sprint week in Vancouver.

April 05, 2016 01:34 PM

March 07, 2016

Kim Moir (kmoir)

RelEng & RelOps Weekly highlights - March 4, 2016

It was a busy week with many releases in flight, as well as preparation for running beta 1 with release promotion next week.  We also are in the process of adding more capacity to certain test platform pools to lower wait times given all the new e10s tests that have been enabled.

Improve Release Pipeline:
Everyone gets a release promotion!  Source: http://i.imgur.com/WMmqSDI.jpg

Improve CI Pipeline:

Release:

The releases calendar is getting busier as we get closer to the end of the cycle. Many releases were shipped or are still in-flight:
As always, you can find more specific release details in our post-mortem minutes:
https://wiki.mozilla.org/Releases:Release_Post_Mortem:2016-03-02 
https://wiki.mozilla.org/Releases:Release_Post_Mortem:2016-03-09

Operational:

Until next time!

March 07, 2016 03:56 PM

February 29, 2016

Kim Moir (kmoir)

RelEng & RelOps Weekly highlights - February 26, 2016

It was a busy week for release engineering as several team members travelled to the Vancouver office to sprint on the release promotion project. The goal of the release promotion project is to promote continuous integration builds to release channels, allowing us to ship releases much more quickly.



Improve Release Pipeline:


Improve CI Pipeline:

Release:

Operational:

February 29, 2016 08:22 PM

January 21, 2016

Rail Alliev (rail)

Rebooting productivity

Every new year gives you an opportunity to sit back, relax, have some scotch and re-think the passed year. Holidays give you enough free time. Even if you decide to not take a vacation around the holidays, it's usually calm and peaceful.

This time, I found myself thinking mostly about productivity, being effective, feeling busy, overwhelmed with work and other related topics.

When I started at Mozilla (almost 6 years ago!), I tried to apply all my GTD and time management knowledge and techniques. Working remotely and in a different time zone was an advantage - I had close to zero interruptions. It worked perfect.

Last year I realized that my productivity skills had faded away somehow. 40h+ workweeks, working on weekends, delivering goals in the last week of quarter don't sound like good signs. Instead of being productive I felt busy.

"Every crisis is an opportunity". Time to make a step back and reboot myself. Burning out at work is not a good idea. :)

Here are some ideas/tips that I wrote down for myself you may found useful.

Concentration

  • Task #1: make a daily plan. No plan - no work.

  • Don't start your day by reading emails. Get one (little) thing done first - THEN check your email.

  • Try to define outcomes, not tasks. "Ship XYZ" instead of "Work on XYZ".

  • Meetings are time consuming, so "Set a goal for each meeting". Consider skipping a meeting if you don't have any goal set, unless it's a beer-and-tell meeting! :)

  • Constantly ask yourself if what you're working on is important.

  • 3-4 times a day ask yourself whether you are doing something towards your goal or just finding something else to keep you busy. If you want to look busy, take your phone and walk around the office with some papers in your hand. Everybody will think that you are a busy person! This way you can take a break and look busy at the same time!

  • Take breaks! Pomodoro technique has this option built-in. Taking breaks helps not only to avoid RSI, but also keeps your brain sane and gives you time to ask yourself the questions mentioned above. I use Workrave on my laptop, but you can use a real kitchen timer instead.

  • Wear headphones, especially at office. Noise cancelling ones are even better. White noise, nature sounds, or instrumental music are your friends.

(Home) Office

  • Make sure you enjoy your work environment. Why on the earth would you spend your valuable time working without joy?!

  • De-clutter and organize your desk. Less things around - less distractions.

  • Desk, chair, monitor, keyboard, mouse, etc - don't cheap out on them. Your health is more important and expensive. Thanks to mhoye for this advice!

Other

  • Don't check email every 30 seconds. If there is an emergency, they will call you! :)

  • Reward yourself at a certain time. "I'm going to have a chocolate at 11am", or "MFBT at 4pm sharp!" are good examples. Don't forget, you are Pavlov's dog too!

  • Don't try to read everything NOW. Save it for later and read in a batch.

  • Capture all creative ideas. You can delete them later. ;)

  • Prepare for next task before break. Make sure you know what's next, so you can think about it during the break.

This is my list of things that I try to use everyday. Looking forward to see improvements!

I would appreciate your thoughts this topic. Feel free to comment or send a private email.

Happy Productive New Year!

January 21, 2016 02:06 AM

January 08, 2016

Kim Moir (kmoir)

Tips from a resume nerd

Before I begin this post a few caveats:
I'm kind of a resume and interview nerd.  I like helping friends fix their resumes and write amazing cover letters. In the past year I've helped a few (non-Mozilla) friends fix up their resumes, write cover letters, prepare for interviews as they search for new jobs.  This post will discuss some things I've found to be helpful in this process.

Picture by GotCredit - Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)
https://www.flickr.com/photos/jakerust/16223669794/sizes/l

Preparation
Everyone tends to jump into looking at job descriptions and making their resume look pretty. Another scenario is that people have a sudden realization that they need to get out of their current position and find a new job NOW and frantically start applying for anything that matches their qualifications.  Before you do that, take a step back and make a list of things that are important to you.  For example, when I applied at Mozilla, my list was something like this

People spend a lot of time at work. Life is too short to be unhappy every day.  Writing a list of what is important serves as a checklist to when you are looking at job descriptions and immediately weed out the ones that don't match your list.  

Picture by Mufidah Kassalias - Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)
https://www.flickr.com/photos/mufidahkassalias/10519774073/sizes/o/
 
People tend focus a lot on the technical skills they want to use or new ones you want to learn.  You should also think about what kind of culture where you want to work.  Do the goals and ethics of the organization align with your own? Who will you be working with? Will you enjoy working with this team?  Are you interested in remote work or do you want to work in an office? How will a long commute impact or relocation your quality of life? What is the typical career progression of someone in this role? Are there both management and technical tracks for advancement?


Picture by mugley - Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) https://www.flickr.com/photos/mugley/4221455156/sizes/o/


To summarize, itemize the skills you'd like to use or learn, the culture of the company and the team and why you want to work there.

Cover letter

Your cover letter should succinctly map your existing skills to the role you are applying for and convey enthusiasm and interest.  You don't need to have a long story about how you worked on a project at your current job that has no relevance to your potential new employer.  Teams that are looking to hire have problems to solve.  Your cover letter needs to paint a picture that your have the skills to solve them.

Picture by Jim Bauer - Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) https://www.flickr.com/photos/lens-cap/10320891856/sizes/l


Refactoring your resume

Developers have a lot of opportunities these days, but if you intend to move from another industry, into a tech company, it can be more tricky.  The important thing is to convey the skills you have in a a way that people can see they can be applied to the problems they want to hire you to fix. 

Many people describe their skills and accomplishments in a way that is too company specific.  They may have a list of acronyms and product names on their resume that are unlikely to be known by people outside the company.  When describing the work you did in a particular role, describe the work that you did in a that is measurable way that highlights the skills you have.  An excellent example of a resume that describes the skills that without going into company specific detail is here. (Julie Pagano also has a terrific post about how she approached her new job search.)

Another tip is to leave out general skills that are very common.  For instance, if you are a technical writer, omit the fact that you know how to use Windows and Word and focus on highlighting your skills and accomplishments. 


Non-technical interview preparation

Every job has different technical requirements and there are many books and blog posts on how to prepare for this aspect of the interview process. So I'm going to just cover the non-technical aspects.

When I interview someone, I like to hear lots of questions.  Questions about the work we do and upcoming projects.  This indicates that have taken the time to research the team, company and work that we do.  It also shows that enthusiasm and interest.

Here is a list suggestions to prepare for interviews

1.  Research the company make a list of relevant questions
Not every company is open about the work that they do, but most will be have some public information that you can use to formulate questions during the interviews.  Do you know anyone you can have coffee or skype with to who works for the company and can provide insight? What products/services do the company produce? Is the product nearing end of life?  If so, what will it be replaced by? What is the companies market share, is it declining, stable or experiencing growth? Who are their main competitors? What are some of the challenges they face going forward? How will this team help address these challenges?

2.  Prepare a list of questions for every person that interviews you ahead of time
Many companies will give you the list of names of people who will interview you.
Have they recently given talks? Watch the videos online or read the slides.
Does the team have github or other open repositories?  What are recent projects are they working on? Do they have a blog or are active on twitter? If so, read it and formulate some questions to bring to the interview.
Do they use open bug tracking tools?  If so, look at the bugs that have recent activity and add them to the list of questions for your interview. 
A friend of mine read the book of a person that interviewed him had written and asked questions about the book in the interview.  That's serious interview preparation!

Photo by https://www.flickr.com/photos/wocintechchat/ https://www.flickr.com/photos/wocintechchat/22506109386/sizes/l


3. Team dynamics and tools
Is the team growing or are you hiring to replace somebody who left?
What's the onboarding process like? Will you have a mentor?
How is this group viewed by the rest of the company? You want to be in a role where you can make a valuable contribution.  Joining a team where their role is not valued by the company or not funded adequately is a recipe for disappointment.
What does a typical day look like?  What hours do people usually work?
What tools do people use? Are there prescribed tools or are you free to use what you'd like?

4.  Diversity and Inclusion
If you're a member of an underrepresented group in tech, the numbers are lousy in this industry with some notable exceptions. And I say that while recognizing that I'm personally in the group that is the lowest common denominator for diversity in tech. 

The entire thread on this tweet is excellent  https://twitter.com/radiomorillo/status/589158122108932096


I don't really have good advice for this area other than do your research to ensure you're not entering a toxic environment.  If you look around the office where you're being interviewed and nobody looks like you, it's time for further investigation.   Look at the company's website - is the management team page white guys all the way down?  Does the company support diverse conferences, scholarships or internships? Ask on a mailing list like devchix if others have experience working at this company and what it's like for underrepresented groups. If you ask in the interview why there aren't more diverse people in the office and they say something like "well, we only hire on merit" this is a giant red flag. If the answer is along the lines of "yes, we realize this and these are the steps we are taking to rectify this situation",  this is a more encouraging response.

A final piece of advice, ensure that you meet with your manager that you're going to report to as part of your hiring process.  You want to ensure that you have rapport with them and can envision a productive working relationship. 

What advice do you have for people preparing to find a new job?

Further reading

Katherine Daniels gave at really great talk at Beyond the Code 2014 about how to effectively start a new job.  Press start: Beginning a New Adventure Job
She is also the co-author of Effective Devops which has fantastic chapter on hiring.
Erica Joy writes amazing articles about the tech industry and diversity.
Cate Huston has some beautiful posts on how to conduct technical interviews and how to be a better interviewer
Camille Fournier's blog is excellent reading on career progression and engineering management.
Mozilla is hiring!

January 08, 2016 08:37 PM

December 10, 2015

Nick Thomas (nthomas)

Updates for Nightly on Windows

You may have noticed that Windows has had no updates for Nightly for the last week or so. We’ve had a few issues with signing the binaries as part of moving from a SHA-1 certificate to SHA-2. This needs to be done because Windows won’t accept SHA-1 signed binaries from January 1 2016 (this is tracked in bug 1079858).

Updates are now re-enabled, and the update path looks like this

older builds  →  20151209095500  →  latest Nightly

Some people may have been seeing UAC prompts to run the updater, and there could be one more of those when updating to the 20151209095500 build (which is also the last SHA-1 signed build). Updates from that build should not cause any UAC prompts.

December 10, 2015 03:57 PM

November 24, 2015

Kim Moir (kmoir)

USENIX Release Engineering Summit 2015 recap

November 13th, I attended the USENIX Release Engineering Summit in Washington, DC.  This summit was along side the larger LISA conference at the same venue. Thanks to Dinah McNutt, Gareth Bowles, Chris Cooper,  Dan Tehranian and John O'Duinn for organizing.



I gave two talks at the summit.  One was a long talk on how we have scaled our Android testing infrastructure on AWS, as well as a look back at how it evolved over the years.

Picture by Tim Norris - Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)
https://www.flickr.com/photos/tim_norris/2600844073/sizes/o/

Scaling mobile testing on AWS: Emulators all the way down from Kim Moir

I gave a second lightning talk in the afternoon on the problems we face with our large distributed continuous integration, build and release pipeline, and how we are working to address the issues. The theme of this talk was that managing a large distributed system is like being the caretaker for the water, or some days, the sewer system for a city.  We are constantly looking system leaks and implementing system monitoring. And probably will have to replace it with something new while keeping the existing one running.

Picture by Korona Lacasse - Creative Commons 2.0 Attribution 2.0 Generic https://www.flickr.com/photos/korona4reel/14107877324/sizes/l


Distributed Systems at Scale: Reducing the Fail from Kim Moir

In preparation for this talk, I did a lot of reading on complex systems design and designing for recovery from failure in distributed systems.  In particular, I read Donatella Meadows' book Thinking in Systems. (Cate Huston reviewed the book here). I also watched several talks by people who talked about the challenges they face managing their distributed systems including the following:
I'd also like to thank all the members of Mozilla releng/ateam who reviewed my slides and provided feedback before I gave the presentations.
The attendees of the summit attended the same keynote as the LISA attendees.  Jez Humble, well known for his Continuous Delivery and Lean Enterprise books provided a keynote on Lean Configuration Management which I really enjoyed. (Older version of slides from another conference, are available here and here.)



In particular, I enjoyed his discussion of the cultural aspects of devops. I especially like that he stated that "You should not have to have planned downtime or people working outside business hours to release".  He also talked a bit about how many of the leaders that are looked up to as visionaries in the tech industry are known for not treating people very well and this is not a good example to set for others who believe this to be the key to their success.  For instance, he said something like "what more could Steve Jobs have accomplished had he treated his employees less harshly".

Another concept he discussed which I found interesting was that of the strangler application. When moving from a large monolithic application, the goal is to split out the existing functionality into services until the originally application is left with nothing.  Exactly what Mozilla releng is doing as we migrate from Buildbot to taskcluster.


http://www.slideshare.net/jezhumble/architecting-for-continuous-delivery-54192503


At the release engineering summit itself,   Lukas Blakk from Pinterest gave a fantastic talk Stop Releasing off Your Laptop—Implementing a Mobile App Release Management Process from Scratch in a Startup or Small Company.  This included grumpy cat picture to depict how Lukas thought the rest of the company felt when that a more structured release process was implemented.


Lukas also included a timeline of the tasks that implemented in her first six months working at Pinterest. Very impressive to see the transition!


Another talk I enjoyed was Chaos Patterns - Architecting for Failure in Distributed Systems by Jos Boumans of Krux. (Similar slides from an earlier conference here). He talked about some high profile distributed systems that failed and how chaos engineering can help illuminate these issues before they hit you in production.


For instance, it is impossible for Netflix to model their entire system outside of production given that they consume around one third of nightly downstream bandwidth consumption in the US. 

Evan Willey and Dave Liebreich from Pivotal Cloud Foundry gave a talk entitled "Pivotal Cloud Foundry Release Engineering: Moving Integration Upstream Where It Belongs". I found this talk interesting because they talked about how the built Concourse, a CI system that is more scaleable and natively builds pipelines.   Travis and Jenkins are good for small projects but they simply don't scale for large numbers of commits, platforms to test or complicated pipelines. We followed a similar path that led us to develop Taskcluster

There were many more great talks, hopefully more slides will be up soon!

November 24, 2015 03:57 PM

November 16, 2015

Nick Thomas (nthomas)

The latest on firefox/releases/latest

The primary way to download Firefox is at www.mozilla.org, but Mozilla’s Release Engineering team has also maintained directories like

https://ftp.mozilla.org/pub/firefox/releases/latest/

to provide a stable location for scripted downloads. There are similar links for betas and extended support releases for organisations. Read on to learn how these directories have changed, and how you can continue to download the latest releases.

Until recently these directories were implemented using a symlink to the current version, for example firefox/releases/42.0/. The storage backend has now changed to Amazon S3 and this is no longer possible. To implement the same functionality we’d need a duplicate set of keys, which incurs more maintenance overhead. And we already have a mechanism for delivering files independent of the current shipped version – our download redirector Bouncer. For example, here’s the latest release for Windows 32bit, U.S. English:

https://download.mozilla.org/?product=firefox-latest&os=win&lang=en-US

Modifying the product, os, and/or lang allow other combinations. This is described in the README.txt files for beta, release, and esr, as well as the Thunderbird equivalents release and beta.

Please adapt your scripts to use download.mozilla.org links. We hope it will help you simplify at the same time, as scraping to determine the current version is no longer necessary.

PS. We’ve also removed some latest- directories which were old and crufty, eg firefox/releases/latest-3.6.

November 16, 2015 11:37 PM

October 23, 2015

Nick Thomas (nthomas)

Updates disabled for Android Nightly and Aurora

Due to a bug with the new ftp server we’ve had to disable updates for

They’ll resume just as soon as we can get the fix landed.

Update (Oct 25th): Updates are re-enabled, thanks to Mike Shal for the fix.

October 23, 2015 08:39 AM

October 21, 2015

Nick Thomas (nthomas)

Try Server – please use up-to-date code to avoid upload failures

Today we started serving an important set of directories on ftp.mozilla.org using Amazon S3, more details on that over in the newsgroups. Some configuration changes landed in the tree to make that happen.

Please rebase your try pushes to use revision 0ee21e8d5ca6 or later, currently on mozilla-inbound. Otherwise your builds will fail to upload, which means they won’t run any tests. No fun for anyone.

October 21, 2015 10:02 AM

September 26, 2015

Kim Moir (kmoir)

The mystery of high pending counts

In September, Mozilla release engineering started experiencing high pending counts on our test pools, notably Windows, but also Linux (and consequently Android).  High pending counts mean that there are thousands of jobs queued to run on the machines that are busy running other jobs.  The time developers have to wait for their test results is longer than ideal.


Usually, pending counts clear overnight as less code is pushed during the night (in North America) which invokes fewer builds and tests.  However, as you can see from the graph above, the Windows test pending counts were flat last night. They did not clear up overnight. You will also note that try, which usually comprises 63% of our load, has very highest pending counts compared to other branches.  This is because many people land on try before pushing to other branches, and tests aren't coalesced on try.


The work to determine the cause of high pending counts is always an interesting mystery.
Mystery by ©Stuart Richards, Creative Commons by-nc-sa 2.0

Joel Maher and I looked at the data for this last week and discovered what we believe to be the source of the problem.  We have determined that since the end of August a number of new test jobs were enabled that increased the compute time per push on Windows by 13% or 2.5 hours per push.  Most of these new test jobs are for e10s
Increase in seconds that new jobs added to the total compute time per push.  (Some existing jobs also reduced their compute time for a total difference about about 2.5 more hours per push on Windows)
The e10s initiative is an important initiative for Mozilla to make Firefox performance and security even better.  However, since new e10s and old tests will continue to run in parallel, we need to get creative on how to have acceptable wait times given the limitations of our current Windows tests pools.  (All of our Windows test run on bare metal in our datacentre, not on Amazon).
 
Release engineering is working to reduce this pending counts given our current hardware constraints with the following initiatives: 

To reduce Linux pending counts:
  • Added 200 new instances to the tst-emulator64 pool (run Android test jobs on Linux emulators) (bug 1204756)
  • In process of adding more Linux32 and Linux64 buildbot masters (bug 1205409) which will allow us to expand our capacity more

Ongoing work to reduce the Windows pending counts:


How can you help? 

Please be considerate when invoking try pushes and only select the platforms that you explicitly require to test.  Each try push for all platforms and all tests invokes over 800 jobs.

September 26, 2015 12:34 AM

August 03, 2015

Rail Alliev (rail)

Funsize enabled for Nightly builds

Keep calm and update Firefox

Note: this post has been sitting in the drafts queue for some reason. Better to publish it. :)

As of Tuesday, Aug 4, 2015 Funsize has been enabled on mozilla-central. From now on all Nightly builds builds will get updates for builds up to 4 days in the past (for yesterday, for the day before yesterday, etc). This should make people who don't run their nightlies every day happier.

Firefox Developer Edition partial updates will be enabled after 42.0 hits mozilla-aurora, but early adopters can use the aurora-funsize channel.

Partial updates as a part of builds and L10N repacks on nightly will be disabled as soon as Bug 1173459 is resolved.

As a bonus, you can take a look at the presentation I gave in Whistler during the work week.

Reporting Issues

If you see any issues, please report them to Bugzilla.

August 03, 2015 09:22 PM

July 17, 2015

Kim Moir (kmoir)

Learning Data Science and evidence based teaching methods

This spring, I took several online courses on the topic of data science.  I became interested in expanding my skills in this area because as release engineers, we deal with a lot of data.  I wanted to learn new tools to extract useful information from the distributed systems behemoth we manage.


This xckd reminded me of the challenges of managing our buildfarm somedays :-)
From http://xkcd.com/1546/

I took three courses from Coursera's Data Science track from John Hopkins University. As with previous coursera classes I took, all the course material is online (lecture videos and notes).  There are quizzes and assignments that are due each week.  Each course below was about four weeks long.

The Data Scientist's Toolbox - This course was pretty easy. Basically a introduction to the questions that data scientists deal as well a primer on installing R, RStudio (IDE for R), and using GitHub.
R Programming - Introduction to R.  Most of the quizzes and examples used publicly available data for the programming exercises.  I found I had to do a lot of reading in the R API docs or on stackoverflow to finish the assignments.  The lectures didn't provide a lot of the material needed to complete the assignments.  Lots of techniques to learn how to subset data using R which I found quite interesting, reminded me a lot of querying databases with SQL to conduct analysis.
Getting and Cleaning Data - More advanced techniques using R.  Using publicly available data sources to clean different data sources in different formats, XML, excel spreadsheets, comma or tab delimited. Given this data, we had to answer many questions and conduct specific analysis by writing  R programs.  The assignments were pretty challenging and took a long time. Again, the course material didn't really cover all the material you needed to do the assignments so a lot of additional reading was required.

There are six more courses in the Data Science track that I'll start tackling again in the fall that cover subjects such as reproducible research, statistical inference and machine learning.   My next coursera  class is Introduction to Systems Engineering which I'll start in a couple of weeks.  I've really become interested in learning more about this subject after reading Thinking in Systems.

The other course I took this spring was the Software Carpentry Instructor training course.   The Software Carpentry Foundation teachers researchers basic software skills.  For instance, if you are a biologist analyzing large data sets it would be useful to learn how to use R, Python, and version control to store the code you wrote to share with others.  These are not skills that many scientists acquire in their formal university training, and learning them allows them to work more productively.  The instructor course was excellent, thanks Greg Wilson for your work teaching us.

We read two books for this course:
Building a Better Teacher: An interesting overview of how teacher is taught in different countries and how to make it more effective. Most important: Have more opportunities for other teachers to observe your classroom and provide feedback which I found analogous to how code review makes us better software developers.
How Learning Works: Seven Research-Based Principles for Smart Teaching: A book summarizing the research in disciplines such as education, cognitive science and psychology on the effective techniques for teaching students new material.  How assessing student's prior knowledge can help you better design your lessons, how to to ask questions to determine what material students are failing to grasp, how to understand student's motivation for learning and more.  Really interesting research.

For the instructor course, we met every couple of weeks online where Greg would conduct a short discussion on some of the topics on a conference call and we would discuss via etherpad interactively. We would then meet in smaller groups later in the week to conduct practice teaching exercises.  We also submitted example lessons to the course repo on GitHub. The final project for the course was to conduct a short lesson to a group of instructors that gave feedback, and submit a pull request to update an existing lesson with a fix.  Then we are ready to sign up to teach a Software Carpentry course!

In conclusion, data science is a great skill to have if you are managing large distributed systems.  Also, using evidence based teaching methods to help others learn is the way to go!

Other fun data science examples include
Tracking down the Villains: Outlier Detection at Netflix - detecting rogue servers with machine learning
Finding Shoe Stores in 100k Merchants: Using Data to Group All Things - finding out what Shopify merchants sell shoes using Apache Spark and more
Looking Through Camera Lenses: The Application of Computer Vision at Etsy

July 17, 2015 03:41 PM

July 07, 2015

Rail Alliev (rail)

Funsize is ready for testing!

Funsize is very close to be enabled in production! It has undergone a Rapid Risk Assessment procedure, which found a couple of potential issues. Most of them are either resolved or waiting for deployment.

To make sure everything works as expected and to catch some last-minute bugs, I added new update channels for Firefox Nightly and Developer Edition. If you are brave enough, you can use the following instructions and change your update channels to either nightly-funsize (for Firefox Nightly) or aurora-funsize (for Firefox Developer Edition).

TL;DR instruction look like this:

  • Enable update logging. Set app.update.log to true in about:config. This step is optional, but it may help with debugging possible issues.

  • Shut down all running instances of Firefox.

  • Edit defaults/pref/channel-prefs.js in your Firefox installation directory and change the line containing app.update.channel with:

pref("app.update.channel", "aurora-funsize"); // Firefox Developer Edition

or

pref("app.update.channel", "nightly-funsize"); // Firefox Nightly
  • Continue using you Firefox

You can check your channel in the About dialog and it should contain the channel name:

About dialog

Reporting Issues

If you see any issues, please report them to Bugzilla.

July 07, 2015 02:44 PM

June 16, 2015

Kim Moir (kmoir)

Test job reduction by the numbers

In an earlier post,  I wrote how we had reduced the amount of test jobs that run on two branches to allow us to scale our infrastructure more effectively.  We run the tests that historically identify regressions more often.  The ones that don't, we skip on every Nth push.  We now have data on how this reduced the number of jobs we run since we began implementation in April.

We run SETA on two branches (mozilla-inbound and fx-team) and on 18 types of builds.  Collectively, these two branches represent about 20% of pushes each month.  Implementing SETA allowed us to move  from ~400 -> ~240 jobs per push on these two branches1 We run the tests identified as not reporting regressions on every 10th commit or 90 minutes since the last test was scheduled.  We run the critical tests on every commit.2

Reduction in number of jobs per push on mozilla-inbound as SETA scheduling is rolled out

A graph for the fx-team branch shows a similar trend. It was a staged rollout starting in early April, as I enabled platforms and as the SETA data became available. The dip in early June reflects where I enabled SETA for Android 4.3.

This data will continue to be updated in our scheduling configuration as it evolves and is updated by the code that Joel and Vaibhav wrote to analyze regressions. The analysis identifies that there were

Jobs to ignore: 440
Jobs to run: 114
Total number of jobs: 554

which is significant.  Our buildbot configurations are updated the latest SETA data with every reconfig, which occurs usually occurs every couple of days.

The platforms configured to run fewer tests for both opt and debug are

        MacOSX (10.6, 10.10)
        Windows (XP, 7, 8)
        Ubuntu 12.04 for linux32, linux64 and ASAN x64
        Android 2.3 armv7 API 9
        Android 4.3 armv7 API 11+

Additional info
1Tests may have been disabled/added at the same time,  this is not taken into account
2There still some scheduling issues to be fixed see bug 1174870  and bug 1174746 for further details

June 16, 2015 08:55 PM

June 12, 2015

Kim Moir (kmoir)

Less testing, same great Firefox taste!


Running a large continuous integration farm forces you to deal with many dynamic inputs coupled with capacity constraints. The number of pushes increase.  People add more tests.  We build and test on a new platform.  If the number of machines available remains static, the computing time associated with a single push will increase.  You can scale this for platforms that you build and test in the cloud (for us - Linux and Android on emulators), but this costs more money.  Adding hardware for other platforms such as Mac and Windows in data centres is also costly and time consuming.

Do we really need to run every test on every commit? If not, which tests should be run?  How often do they need to be run in order to catch regressions in a timely manner (i.e. able to bisect where the regression occurred)


Several months ago, jmaher and vaibhav1994, wrote code to analyze the test data and determine the minimum number of tests required to run to identify regressions.  They named their software SETA (search for extraneous test automation). They used historical data to determine the minimum set of tests that needed to be run to catch historical regressions.  Previously, we coalesced tests on a number of platforms to mitigate too many jobs being queued for too few machines.  However, this was not the best way to proceed because it reduced the number of times we ran all tests, not just less useful ones.  SETA allows us to run a subset of tests on every commit that historically have caught regressions.  We still run all the test suites, but at a specified interval. 

SETI – The Search for Extraterrestrial Intelligence by ©encouragement, Creative Commons by-nc-sa 2.0
In the last few weeks, I've implemented SETA scheduling in our our buildbot configs to use the data that the analysis that Vaibhav and Joel  implemented.  Currently, it's implemented on mozilla-inbound and fx-team branches which in aggregate represent around 19.6% (March 2015 data) of total pushes to the trees.  The platforms configured to run fewer tests for both opt and debug are

As we gather more SETA data for newer platforms, such as Android 4.3, we can implement SETA scheduling for it as well and reduce our test load.  We continue to run the full suite of tests on all platforms other branches other than m-i and fx-team, such as mozilla-central, try, and the beta and release branches. If we did miss a regression by reducing the tests, it would appear on other branches mozilla-central. We will continue to update our configs to incorporate SETA data as it changes.

How does SETA scheduling work?
We specify the tests that we would like to run on a reduced schedule in our buildbot configs.  For instance, this specifies that we would like to run these debug tests on every 10th commit or if we reach a timeout of 5400 seconds between tests.

http://hg.mozilla.org/build/buildbot-configs/file/2d9e77a87dfa/mozilla-tests/config_seta.py#l692


Previously, catlee had implemented a scheduling in buildbot that allowed us to coallesce jobs on a certain branch and platform using EveryNthScheduler.  However, as it was originally implemented, it didn't allow us to specify tests to skip, such as mochitest-3 debug on MacOSX 10.10 on mozilla-inbound.  It would only allow us to skip all the debug or opt tests for a certain platform and branch.

I modified misc.py to parse the configs and create a dictionary for each test specifying the interval at which the test should be skipped and the timeout interval.  If the tests has these parameters specified, it should be scheduled using the  EveryNthScheduler instead of the default scheduler.

http://hg.mozilla.org/build/buildbotcustom/file/728dc76b5ad0/misc.py#l2727
There are still some quirks to work out but I think it is working out well so far. I'll have some graphs in a future post on how this reduced our test load. 

Further reading
Joel Maher: SETA – Search for Extraneous Test Automation



June 12, 2015 09:02 PM

Mozilla pushes - May 2015

Here's May 2015's monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.


Trends

The number of pushes decreased from those recorded in the previous month (8894) with a total of 8363. 

 
Highlights

General Remarks

Records



June 12, 2015 07:28 PM

Mozilla pushes - April 2015

Here's April 2015's  monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.  


Trends
The number of pushes decreased from those recorded in the previous month with a total of 8894.  This is due to the fact that gaia-try is managed by taskcluster and thus these jobs don't appear in the buildbot scheduling databases anymore which this report tracks.


Highlights


General Remarks


Records




Note
I've changed the graphs to only track 2015 data.  Last month they were tracking 2014 data as well but it looked crowded so I updated them.  Here's a graph showing the number of pushes over the last few years for comparison.



June 12, 2015 07:06 PM

April 28, 2015

Kim Moir (kmoir)

Releng 2015 program now available

Releng 2015 will take place in concert with ICSE in Florence, Italy on May 19, 2015. The program is now available. Register here!

via romana in firenze by ©pinomoscato, Creative Commons by-nc-sa 2.0



April 28, 2015 07:54 PM

April 21, 2015

Nick Thomas (nthomas)

Changes coming to ftp.mozilla.org

ftp.mozilla.org has been around for a long time in the world of Mozilla, dating back to original source release in 1998. Originally it was a single server, but it’s grown into a cluster storing more than 60TB of data, and serving more than a gigabit/s in traffic. Many projects store their files there, and there must be a wide range of ways that people use the cluster.

This quarter there is a project in the Cloud Services team to move ftp.mozilla.org (and related systems) to the cloud, which Release Engineering is helping with. It would be very helpful to know what functionality people are relying on, so please complete this survey to let us know. Thanks!

April 21, 2015 02:47 AM

April 15, 2015

Kim Moir (kmoir)

Mozilla pushes - March 2015

Here's March 2015's  monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.

Trends
The number of pushes increased from those recorded in the previous month with a total of 10943. 

Highlights

General Remarks

Records





April 15, 2015 02:18 PM

March 31, 2015

Rail Alliev (rail)

Taskcluster: First Impression

Good news. We decided to redesign Funsize a little and now it uses Taskcluster!

The nature of Funsize is that we may start hundreds of jobs at the same time, then stop sending new jobs and wait for hours. In other words, the service is very bursty. Elastic Beanstalk is not ideal for this use case. Scaling up and down very fast is hard to configure using EB-only tools. Also, running zero instances is not easy.

I tried using Terraform, Cloud Formation and Auto Scaling, but they were also not well suited. There were too many constrains (e.g. Terraform doesn't support all needed AWS features) and they required considerable bespoke setup/maintenance to auto-scale properly.

The next option was Taskcluster, and I was pleased that its design fitted our requirements very well! I was impressed by the simplicity and flexibility offered.

I have implemented a service which consumes Pulse messages for particular buildbot jobs. For nightly builds, it schedules a task graph with three tasks:

  • generate a partial MAR

  • sign it (at the moment a dummy task)

  • publish to Balrog

All tasks are run inside Docker containers which are published on the docker.com registry (other registries can also be used). The task definition essentially comprises of the docker image name and a list of commands it should run (usually this is a single script inside a docker image). In the same task definition you can specify what artifacts should be published by Taskcluster. The artifacts can be public or private.

Things that I really liked

  • Predefined task IDs. This is a great idea! There is no need to talk to the Taskcluster APIs to get the ID (or multiple IDs for task graphs) nor need to parse the response. Fire and forget! The task IDs can be used in different places, like artifact URLs, dependant tasks, etc.

  • Task graphs. This is basically a collection of tasks that can be run in parallel and can depend on each other. This is a nice way to declare your jobs and know them in advance. If needed, the task graphs can be extended by its tasks (decision tasks) dynamically.

  • Simplicity. All you need is to generate a valid JSON document and submit it using HTTP API to Taskcluster.

  • User defined docker images. One of the downsides of Buildbot is that you have a predefined list of slaves with predefined environment (OS, installed software, etc). Taskcluster leverages Docker by default to let you use your own images.

Things that could be improved

  • Encrypted variables. I spent 2-3 days fighting with the encrypted variables. My scheduler was written in Python, so I tried to use a half dozen different Python PGP libraries, but for some reason all of them were generating an incompatible OpenPGP format that Taskcluster could not understand. This forced me to rewrite the scheduling part in Node.js using openpgpjs. There is a bug to address this problem globally. Also, using ISO time stamps would have saved me hours of time. :)

  • It would be great to have a generic scheduler that doesn't require third party Taskcluster consumers writing their own daemons watching for changes (AMQP, VCS, etc) to generate tasks. This would lower the entry barrier for beginners.

Conclusion

There are many other things that can be improved (and I believe they will!) - Taskcluster is still a new project. Regardless of this, it is very flexible, easy to use and develop. I would recommend using it!

Many thanks to garndt, jonasfj and lightsofapollo for their support!

March 31, 2015 12:47 PM

March 20, 2015

Kim Moir (kmoir)

Scaling Yosemite

We migrated most of our Mac OS X 10.8 (Mountain Lion) test machines to 10.10.2 (Yosemite) this quarter.

This project had two major constraints:
1) Use the existing hardware pool (~100 r5 mac minis)
2) Keep wait times sane1.  (The machines are constantly running tests most of the day due to the distributed nature of the Mozilla community and this had to continue during the migration.)

So basically upgrade all the machines without letting people notice what you're doing!

Yosemite Valley - Tunnel View Sunrise by ©jeffkrause, Creative Commons by-nc-sa 2.0

Why didn't we just buy more minis and add them to the existing pool of test machines?
  1. We run performance tests and thus need to have all the machines running the same hardware within a pool so performance comparisons are valid.  If we buy new hardware, we need to replace the entire pool at once.  Machines with different hardware specifications = useless performance test comparisons.
  2. We tried to purchase some used machines with the same hardware specs as our existing machines.  However, we couldn't find a source for them.  As Apple stops production of old mini hardware each time they announce a new one, they are difficult and expensive to source.
Apple Pi by ©apionid, Creative Commons by-nc-sa 2.0

Given that Yosemite was released last October, why we are only upgrading our test pool now?  We wait until the population of users running a new platform2 surpass those the old one before switching.

Mountain Lion -> Yosemite is an easy upgrade on your laptop.  It's not as simple when you're updating production machines that run tests at scale.

The first step was to pull a few machines out of production and verify the Puppet configuration was working.  In Puppet, you can specify commands to only run certain operating system versions. So we implemented several commands to accommodate changes for Yosemite. For instance, changing the default scrollbar behaviour, new services that interfere with test runs needed to be disabled, debug tests required new Apple security permissions configured etc.

Once the Puppet configuration was stable, I updated our configs so the people could run tests on Try and allocated a few machines to this pool. We opened bugs for tests that failed on Yosemite but passed on other platforms.  This was a very iterative process.  Run tests on try.  Look at failures, file bugs, fix test manifests. Once we had to the opt (functional) tests in a green state on try, we could start the migration.

Migration strategy
We currently have 14 machines left on Mountain Lion for mozilla-beta and mozilla-release branches.

As a I mentioned earlier, the two constraints with this project were to use the existing hardware pool that constantly runs tests in production and keep the existing wait times sane.  We encountered two major problems that impeded that goal:

It's a compliment when people say things like "I didn't realize that you updated a platform" because it means the upgrade did not cause large scale fires for all to see.  So it was a nice to hear that from one of my colleagues this week.

Thanks to philor, RyanVM and jmaher for opening bugs with respect to failing tests and greening them up.  Thanks to coop for many code reviews. Thanks dividehex for reimaging all the machines in batches and to arr for her valiant attempts to source new-to-us minis!

References
1Wait times represent the time from when a job is added to the scheduler database until it actually starts running. We usually try to keep this to under 15 minutes but this really varies on how many machines we have in the pool.
2We run tests for our products on a matrix of operating systems and operating system versions. The terminology for operating system x version in many release engineering shops is a platform.  To add to this, the list of platform we support varies across branches.  For instance, if we're going to deprecate a platform, we'll let this change ride the trains to release.

Further reading
Bug 1121175: [Tracking] Fix failing tests on Mac OSX 10.10 
Bug 1121199: Green up 10.10 tests currently failing on try 
Bug 1126493: rollout 10.10 tests in a way that doesn't impact wait times
Bug 1144206: investigate what is causing frequent talos failures on 10.10
Bug 1125998: Debug tests initially took 1.5-2x longer to complete on Yosemite


Why don't you just run these tests in the cloud?
  1. The Apple EULA severely restricts virtualization on Mac hardware. 
  2. I don't know of any major cloud vendors that offer the Mac as a platform.  Those that claim they do are actually renting racks of Macs on a dedicated per host basis.  This does not have the inherent scaling and associated cost saving of cloud computing.  In addition, the APIs to manage the machines at scale aren't there.
  3. We manage ~350 Mac minis.  We have more experience scaling Apple hardware than many vendors. Not many places run CI at Mozilla scale :-) Hopefully this will change and we'll be able to scale testing on Mac products like we do for Android and Linux in a cloud.

March 20, 2015 06:52 PM

March 17, 2015

Kim Moir (kmoir)

Mozilla pushes - February 2015

Here's February's 2015 monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.

Trends
Although February is a shorter month, the number of pushes were close to those recorded in the previous month.  We had a higher average number of daily pushes (358) than in January (348).

Highlights
10015 pushes
358 pushes/day (average)
Highest number of pushes/day: 574 pushes on Feb 25, 2015
23.18 pushes/hour (highest)

General Remarks
Try had around 46% of all the pushes
The three integration repositories (fx-team, mozilla-inbound and b2g-inbound) account around 22% of all the pushes

Records
August 2014 was the month with most pushes (13090  pushes)
August 2014 has the highest pushes/day average with 422 pushes/day
July 2014 has the highest average of "pushes-per-hour" with 23.51 pushes/hour
October 8, 2014 had the highest number of pushes in one day with 715 pushes 





March 17, 2015 03:54 PM

March 02, 2015

Kim Moir (kmoir)

Release Engineering special issue now available

The release engineering special issue of IEEE software was published yesterday. (Download pdf here).  This issue focuses on the current state of release engineering, from both an industry and research perspective. Lots of exciting work happening in this field!

I'm interviewed in the roundtable article on the future of release engineering, along with Chuck Rossi of Facebook and Boris Debic of Google.  Interesting discussions on the current state of release engineering at organizations that scale large number of builds and tests, and release frequently.  As well,  the challenges with mobile releases versus web deployments are discussed. And finally, a discussion of how to find good release engineers, and what the future may hold.

Thanks to the other guest editors on this issue -  Stephany Bellomo, Tamara Marshall-Klein, Bram Adams, Foutse Khomh and Christian Bird - for all their hard work that make this happen!


As an aside, when I opened the issue, the image on the front cover made me laugh.  It's reminiscent of the cover on a mid-century science fiction anthology.  I showed Mr. Releng and he said "Robot birds? That is EXACTLY how I pictured working in releng."  Maybe it's meant to represent that we let software fly free.  In any case, I must go back to tending the flock of robotic avian overlords.

March 02, 2015 02:48 PM

February 23, 2015

Nick Thomas (nthomas)

FileMerge bug

FileMerge is a nice diff and merge tool for OS X, and I use it a lot for larger code reviews where lots of context is helpful. It also supports intra-line diff, which comes in pretty handy.

filemerge screenshot

However in recent releases, at least in v2.8 which comes as part of XCode 6.1, it assumes you want to be merging and shows that bottom pane. Adjusting it away doesn’t persist to the next time you use it, *gnash gnash gnash*.

The solution is to open a terminal and offer this incantation:

defaults write com.apple.FileMerge MergeHeight 0

Unfortunately, if you use the merge pane then you’ll have to do that again. Dear Apple, pls fix!

February 23, 2015 09:23 AM

February 15, 2015

Rail Alliev (rail)

Funsize hacking

Prometheus

The idea of using a service which can generate partial updates for Firefox has been around for years. We actually used to have a server called Prometheus that was responsible for generating updates for nightly builds and the generation was done as a separate process from actual builds.

Scaling that solution wasn't easy and we switched to build-time update generation. Generating updates as a part of builds helped with load distribution, but lacked of flexibility: there is no easy way to generate updates after the build, because the update generation process is directly tied to the build or repack process.

Funsize willl solve the problems listed above: to distribute load and to be flexible.

Last year Anhad started and Mihai continued working on this project. They have done a great job and created a solution that can easily be scaled.

Funsize is split into several pieces:

  • REST API fronted powered by Flask. It's responsible for accepting partial generation requests, forwarding them to the queue and returning generated partials.

  • Celery-based workers to generate partial updates and upload them to S3.

  • SQS or RabbitMQ to coordinate Celery workers.

One of the biggest gains of Funsize is that it uses a global cache to speed up partial generation. For example, after we build an en-US Windows build, we ask Funsize to generate a partial. Then a swarm of L10N repacks (almost a hundred of them per platform) tries to do a similar job. Every single one asks for a partial update. All L10N builds have something in common, and xul.dll is one of the biggest files. Since the files are identical there is no reason to not reuse the previously generated binary patch for that file. Repeat 100 times for multiple files. PROFIT!

The first prototype of Funsize lives at github. If you are interested in hacking, read the docs on how to set up your developer environment. If you don't have an AWS account, it will use a local cache.

Note: this prototype may be redesigned and switch to using TaskCluster. Taskcluster is going to simplify the initial design and reduce dependency on always online infrastructure.

February 15, 2015 04:32 AM

February 13, 2015

Kim Moir (kmoir)

Mozilla pushes - January 2015

Here's January 2015's monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.

Trends
We're back to regular volume after the holidays. Also, it's really cold outside in some parts of the of the Mozilla world.  Maybe committing code > going outside.


Highlights
10798 pushes
348 pushes/day (average)
Highest number of pushes/day: 562 pushes on Jan 28, 2015
18.65 pushes/hour (highest)

General Remarks
Try had around around 42% of all the pushes
The three integration repositories (fx-team, mozilla-inbound and b2g-inbound) account around 24% of all of the pushes

Records
August 2014 was the month with most pushes (13,090  pushes)
August 2014 has the highest pushes/day average with 422 pushes/day
July 2014 has the highest average of "pushes-per-hour" with 23.51 pushes/hour
October 8, 2014 had the highest number of pushes in one day with 715 pushes 




February 13, 2015 04:13 PM

February 04, 2015

Rail Alliev (rail)

Deploying your code from github to AWS Elastic Beanstalk using Travis

I have been playing with Funsize a lot recently. One of the goals was iterating faster:

I have hit some challenges with both Travis and Elastic Beanstalk.

The first challenge was to run the integration (actually end-to-end) tests in the same environment. Funsize uses Docker for both hacking and production environments. Unfortunately it's not possible to create Docker images as a part of Travis job (there is a option to run jobs inside Docker, but this is a different beast).

A simple bash script works around this problem. It starts all services we need in background and runs the end-to-end tests. The end-to-end test asks Funsize to generate several partial MAR files, downloads identical files from Mozilla's FTP server and compares their content skipping the cryptographic signature (Funsize does not sign MAR files).

The next challenge was deploying the code. We use Elastic Beanstalk as convenient way to run simple services. There is a plan to use something else for Funsize, but at the moment it's Elastic Beanstalk.

Travis has support for Elastic Beanstalk, but it's still experimental and at the moment of writing this post there were no documentation on the official website. The .travis.yml file looks straight forward and worked fine. The only minor issue I hit was long commit message.

# .travis.yml snippet
deploy:
    - provider: elasticbeanstalk
      app: funsize # Elastic Beanstalk app name
      env: funsize-dev-rail # Elastic Beanstalk env name
      bucket_name: elasticbeanstalk-us-east-1-314336048151 # S3 bucket used by Elastic Beanstalk
      region: us-east-1
      access_key_id:
        secure: "encrypted key id"
      secret_access_key:
        secure: "encrypted key"
      on:
          repo: rail/build-funsize # Deploy only using my user repo for now
          all_branches: true
          # deploy only if particular jobs in the job matrix passes, not any
          condition: $FUNSIZE_S3_UPLOAD_BUCKET = mozilla-releng-funsize-travis

Having the credentials in a public version control system, even if they are encrypted, makes me very nervous. To minimize possible harm in case something goes wrong I created a separate user in AWS IAM. I couldn't find any decent docs on what permissions a user should have to be able to deploy something to Elastic Beanstalk. It took a while to figure out the this minimal set of permissions. Even with these permissions the user looks very powerful with limited access to EB, S3, EC2, Auto Scaling and CloudFormation.

Conclusion: using Travis for Elastic Beanstalk deployments is quite stable and easy to use (after the initial setup) unless you are paranoid about some encrypted credentials being available on github.

February 04, 2015 02:09 AM

January 21, 2015

Kim Moir (kmoir)

Reminder: Releng 2015 submissions due Friday, January 23

Just a reminder that submissions for the Releng 2015 conference are due this Friday, January 23. 

It will be held on May 19, 2015 in Florence Italy.

If you've done recent work like
we'd love to hear from you.  Please consider submitting a talk!

In addition, if you have colleagues that work in this space that might have interesting topics to discuss at this workshop, please forward this information. I'm happy to talk to people about the submission process or possible topics if there are questions.

Il Duomo di Firenze by ©eddi_07, Creative Commons by-nc-sa 2.0


Sono nel comitato che organizza la conferenza Releng 2015 che si terrà il 19 Maggio 2015 a Firenze. La scadenza per l’invio dei paper è il 23 Gennaio 2015.

http://releng.polymtl.ca/RELENG2015/html/index.html

se avete competenze in:
e volete discutere della vostra esperienza, inviateci una proposta di talk!

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More information
Releng 2015 web page
Releng 2015 CFP now open

January 21, 2015 08:36 PM

January 16, 2015

Nick Thomas (nthomas)

Plans for 2015 – Revamping the Release Automation

Mozilla’s Release Engineering team has been through several major iterations of our “release automation”, which is how we produce the bits for Firefox betas and releases. With each incarnation, the automation has become more reliable, supported more functionality, and end-to-end time has reduced. If you go back a few years to Firefox 2.0 it took several days to prepare 40 or so locales and three platforms for a release; now it’s less than half a day for 90 locales and four platforms. The last major rewrite was some time ago so it’s time to embark on a big revamp – this time we want to reduce the end-to-end time significantly.

Currently, when a code change lands in the repository (eg mozilla-beta) a large set of compile and test jobs are started. It takes about 5 hours for the slowest platform to complete an optimized build and run the tests, in part because we’re using Profile-Guided Optimization (PGO) and need to link XUL twice. Assuming the tests have passed, or been recognized as an intermittent failure, a Release Manager will kick off the release automation. It will tag the gecko and localization repositories, and a second round of compilation will start, using the official branding and other release-specific settings. Accounting for all the other release work (localized builds, source tarballs, updates, and so on) the automation takes 10 or more hours to complete.

The first goal of the revamp is to avoid the second round of compilation, with all the loss of time and test coverage it brings. Instead, we’re looking at ‘promoting’ the builds we’ve already done (in the sense of rank, not marketing). By making some other improvements along the way, eg fast generation of partial updates using funsize, we may be able to save as much as 50% from the current wall time. So we’ll be able to ship fixes to beta users more often than twice a week, get feedback earlier in the cycle, and be more confident about shipping a new release. It’ll help us to ship security fixes faster too.

We’re calling this ‘Build Promotion’ for short, and you can follow progress in Bug 1118794 and dependencies.

January 16, 2015 10:08 AM

January 13, 2015

Kim Moir (kmoir)

Mozilla pushes - December 2014


Here's December 2014's monthly analysis of the pushes to our Mozilla development trees. You can load the data as an HTML page or as a json file.

Trends
There was a low number of pushes this month.  I expect this is due to the Mozilla all-hands in Portland in early December where we were encouraged to meet up with other teams instead of coding :-) and the holidays at the end of the month for many countries.
As as side node, in 2014 we had a total number of 124423 pushes, compared to 79233 in 2013 which represents a growth rate of 57% this year.

Highlights
7836 pushes
253 pushes/day (average)
Highest number of pushes/day: 706 pushes on Dec 17, 2014
15.25 pushes/hour (highest)

General Remarks
Try had around around 46% of all the pushes
The three integration repositories (fx-team, mozilla-inbound and b2g-inbound) account around 23% of all of the pushes

Records
August 2014 was the month with most pushes (13,090  pushes)
August 2014 has the highest pushes/day average with 422 pushes/day
July 2014 has the highest average of "pushes-per-hour" with 23.51 pushes/hour
October 8, 2014 had the highest number of pushes in one day with 715 pushes 







January 13, 2015 03:17 PM