first_shutdown_summary table is a summary of the
Ping latency was reduced through the shutdown ping-sender mechanism in Firefox 55. To maintain consistent historical behavior, the first main ping is not sent until the second start up. In Firefox 57, a separate first-shutdown ping was created to evaluate first-shutdown behavior while maintaining backwards compatibility.
In many cases, the first-shutdown ping is a duplicate of the main ping. The first-shutdown summary can be used in conjunction with the main summary by taking the union and deduplicating on the
The data can be accessed as
The data is backfilled to 2017-09-22, the date of its first nightly appearance. This data should be available to all releases on and after Firefox 57.