Perfetto UI Release Process

The UI has three release channels which are configured by the channels.json file. The channels are:

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

The release process is based around a four week cycle.

Week 1: Update canary to HEAD.
Week 2: Update canary to HEAD. 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: Update stable to current canary, update canary to HEAD.

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 co -b ui-canary -t origin/ui-canary
git cherry-pick -x $SHA1_OF_ORIGINAL_CL
git cl upload

# Repeat for origin/ui-stable branch if needed.

Once the cherry-picks are landed, send out a CL to update the channels.json in the main branch. See r.android.com/1726101 for an example.

{
  "channels": [
    {
      "name": "stable",
      "rev": "6dd6756ffbdff4f845c4db28e1fd5aed9ba77b56"
      //     ^ This should point to the HEAD of origin/ui-stable.
    },
    {
      "name": "canary",
      "rev": "3e21f613f20779c04b0bcc937f2605b9b05556ad"
      //     ^ This should point to the HEAD of origin/ui-canary.
    },
    {
      "name": "autopush",
      "rev": "HEAD"
      //     ^ Don't touch this one.
    }
  ]
}

The state of channels.json in the other branches is irrelevant, the release infrastructure only looks at the main branch to determine the pinning of each channel.

After the channels.json CL lands, the build infrastructure will pick it up and update ui.perfetto.dev within ~30 mins.

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