914756 - [graph server] Don't send Talos regression email if an alert was already sent for the same test with a narrower range

Status: RESOLVED INCOMPLETE

(Release Engineering :: General, defect)

Description

[Matt Brubeck (:mbrubeck)]

We get a lot of noise on dev-tree-management whenever a regression or improvement is merged from branch to branch.  We should suppress email alerts for any regression whose changeset range is a superset of one from a previous alert for the same test.

For example, if we send an alert that TResize on regressed on Mac OS X 10.7 on mozilla-inbound changeset 0123abcdef, then we should not bother sending an alert when it regresses on a merge to mozilla-central that includes 0123abcdef, because this does not give us any useful new information.

We currently store a history of past alerts in the "warning_history.json" file that is loaded here:
http://hg.mozilla.org/graphs/file/644d377c3d42/server/analysis/analyze_talos.py#l288

To fix this bug, we would need to change the warning history to ignore branches, and to store and compare complete changeset ranges rather than just the tipmost changeset of each range.