releases-comm-central/docs/telemetry/index.md

Notes on Glean/Telemetry in Thunderbird

Hooking into the build process

The comm-central definitions in comm/mail/metrics.yaml, comm/mail/pings.yaml and comm/mail/tags.yaml are used in addition to their mozilla-central counterparts..

As part of the mozilla-central telemetry build process, scripts are used to generate the C++ files which define the probe registry (enums, string tables etc).

Because of this code generation, the extra comm-central probe definitions need to be included when the mozilla-central Glean is built.

This is done by setting MOZ_GLEAN_EXTRA_* config values. You can see these in comm/mail/moz.configure. These config values are used by toolkit/components/glean/moz.build (mozilla-central) to pass the extra probe definitions to the code generation scripts.

The build scripts can be found under toolkit/components/telemetry/build_scripts. They are written in Python.

Naming probes

To avoid clashing with the mozilla-central probes, we'll be pretty liberal about slapping on prefixes to our definitions.

Compile-time switches

Telemetry is compiled in by default for Nightly and Official builds. To enable for unofficial builds, add the following line to your mozconfig (lack of a value is intentional):

ac_add_options MOZ_TELEMETRY_REPORTING=

Runtime prefs for testing

There are a few user.js settings you'll want to set up for enabling telemetry local builds:

Send telemetry to a local server

To set the Glean end point to a locally-running http server on port 8080, use:

user_pref("telemetry.fog.test.localhost_port", 8080);
user_pref("datareporting.healthreport.uploadEnabled", true);

For a simple test server, try https://github.com/mozilla/gzipServer (or alternatively https://github.com/bcampbell/webhole).

Bypass data policy checks

The data policy checks make sure the user has been shown and has accepted the data policy. Bypass them with:

user_pref("datareporting.policy.dataSubmissionPolicyBypassNotification",true);
user_pref("datareporting.policy.dataSubmissionEnabled", true);

Enable telemetry tracing

For logging, see https://firefox-source-docs.mozilla.org/toolkit/components/glean/dev/testing.html#logging

Troubleshooting

Sending test pings

Go to about:glean - you can find it on Help | Troubleshooting information (about:support).

Further documentation

The Glean documentation is at:

https://docs.telemetry.mozilla.org/concepts/glean/glean.html