Telemetry pings

A Telemetry ping is the data that we send to Mozilla’s Telemetry servers.

The top-level structure is defined by the common ping format. This is a JSON object which contains:

• some basic information shared between different ping types

• the environment data (optional)

• the data specific to the ping type, the payload.

Ping types

We send Telemetry with different ping types. The main ping is the ping that contains the bulk of the Telemetry measurements for Firefox. For more specific use-cases, we send other ping types.

Pings sent from code that ships with Firefox are listed in the data documentation.

Important examples are:

• main - contains the information collected by Telemetry (Histograms, Scalars, …)

• saved-session - has the same format as a main ping, but it contains the “classic” Telemetry payload with measurements covering the whole browser session. This is only a separate type to make storage of saved-session easier server-side. As of Firefox 61 this is sent on Android only.

• crash - a ping that is captured and sent after a Firefox process crashes.

• new-profile - sent on the first run of a new profile.

• update - sent right after an update is downloaded.

• deletion-request - sent when FHR upload is disabled