When archiving is enabled through the relevant pref (
toolkit.telemetry.archive.enabled), pings submitted to
TelemetryController are also stored locally in the user profile directory, in
To allow for cheaper lookup of archived pings, storage follows a specific naming scheme for both the directory and the ping file name: <YYYY-MM>/<timestamp>.<UUID>.<type>.jsonlz4.
<YYYY-MM>- The subdirectory name, generated from the ping creation date.
<timestamp>- Timestamp of the ping creation date.
<UUID>- The ping identifier.
<type>- The ping type.
Archived data can be viewed on
Archived pings are not kept around forever. After startup of Firefox and initialization of Telemetry, the archive is cleaned up if necessary.
Old ping data is removed by month if it is older than 60 days.
If the total size of the archive exceeds the quota of 120 MB, pings are removed to reduce the size of the archive again.