Perfetto UI Release Process

The UI has three release channels. Each channel is served from the HEAD of a long-lived branch:

stable, the version served by default on ui.perfetto.dev. Served from the stable branch and updated every four weeks.
canary, a less stable but fresher release. Updated every 1-2 weeks. Served from the canary branch.
autopush, the current HEAD version of the UI. Unstable. Served from the main branch.

The release process is based around a four week cycle.

Week 1: Cut canary from main.
Week 2: Cut canary from main. Canary stabilization week 1/2 starts here. Only critical bug fixes can be cherry-picked onto canary.
Week 3: Canary stabilization week 2/2.
Week 4: Promote current canary to stable, then cut canary from main.

After the fourth week the cycle repeats from week one. This is so that:

Canary soaks for two weeks before being promoted to stable.
Newer features can be tried out in Canary within a week, or two at most (if in the stabilization weeks).
Stable users aren't disrupted more than once per month.

Changing release channel

NOTE: The channel setting is persistent across page reloads.

The channel the UI is currently using is displayed in the top left corner. If the tag after the logo shows autopush or canary that is the current channel and if no tag is displayed the current channel is stable.

To change the channel the UI is using between stable and canary you can use the toggle on the entrance page.

To change to the autopush channel, open the Flags screen in the Support section of the sidebar, and choose Autopush in Release channel.

Which version am I using?

You can see the version of the UI you are currently using in the bottom left hand corner of the UI.

Clicking on the version number takes you to GitHub where you can see which commits are part of this version. The version number format is v<maj>.<min>.<Commit SHA1 prefix> where <maj>.<min> are extracted from the top entry in the CHANGELOG.

Cherry-picking a change

If a change needs to be backported onto canary or stable branches, do the following:

git fetch origin
git checkout -b cherry-pick-canary origin/canary
git cherry-pick -x $SHA1_OF_ORIGINAL_CL
git cl upload

# Repeat from origin/stable if needed.

Once the cherry-pick lands on canary or stable, the push to that branch triggers Cloud Build for the corresponding UI channel. There is no separate channel pinning file to update.

To do the normal release-channel moves, use the GitHub Actions workflows:

Cut canary (open PR merging main -> canary) opens a PR against canary. When that PR is merged, Cloud Build redeploys the canary channel.
Promote to stable (open PR merging canary -> stable) opens a PR against stable. When that PR is merged, Cloud Build redeploys the stable channel and tag-on-stable-push.yml creates the release tag and draft release.

Googlers: You can check build progress and logs on go/perfetto-ui-build-status. See also go/perfetto-ui-autopush and go/perfetto-ui-channels for the design docs of the serving infrastructure.

Publishing the Perfetto Chrome extension

Googlers: see go/perfetto-release-chrome-extension