Preferences and Defines¶
This determines whether the Glean SDK is enabled.
It can be controlled by users via
If this is set to false from true, we send a
and no data collections will be persisted or reported from that point.
If set to a value
port which is greater than 0, pings will be sent to
http://localhost:port instead of
If set to a value
port which is less than 0, FOG will:
Tell Glean that upload is enabled, even if it isn’t.
Take all pings scheduled for upload and drop them on the floor, telling the Glean SDK that it was sent successfully.
This is how you emulate “recording enabled but upload disabled”
like developer builds have in Firefox Telemetry.
When switching from
port < 0 to
port >= 0,
Glean will be told (if just temporarily) that upload is disabled.
This clears the stores of recorded-but-not-reported data.
Defaults to 0.
This pair of prefs control the length of time of activity before inactivity (or vice versa) needed before FOG informs the SDK’s Client Activity API that the client was (in)active. Present to allow testing without figuring out how to mock Rust’s clock. Their values are integer seconds. Defaults to 120 (activity), 1200 (inactivity).
Read-only. This pref is
true only if
MOZ_ARTIFACT_BUILDS was set during configure.
If true, JOG is enabled so that artifact builds will exhibit changes to their Glean metrics.
If set, and
GLEAN_SOURCE_TAGS isn’t set, FOG will set a
Glean source tag
GLEAN_SOURCE_TAGS is set, the
automation source tag will not be added automatically.
If not set, any tags set by
GLEAN_SOURCE_TAGS will be present.
If set, the Glean SDK is assumed to be managed by something other than FOG, meaning:
GIFFT is disabled.
FOG doesn’t initialize Glean
FOG doesn’t relay (in)activity or experiment annotations to Glean
If unset, we set a
glean_disable_upload Rust feature in
gkrust-shared which is forwarded to
This feature defaults FOG to an “upload disabled”
mode where collection on the client proceeds as normal but no ping is sent.
This mode can be overridden at runtime in two ways:
If the preference
telemetry.fog.test.localhost_portis set to a value greater than 0, then pings are sent to a server operating locally at that port (even if the ping has a Debug Tag), to enable testing.
MOZILLA_OFFICIAL tends to be set on most builds released to users,
including builds distributed by Linux distributions.
It tends to not be set on local developer builds.
See bug 1680025 for details.
If not set to
'Android' we set a
glean_million_queue Rust feature
which, when passed to the Glean SDK,
opts us into a preinit queue that doesn’t discard tasks until there are 10^6 of them.
See bug 1797494 for details.