DrydockLeaseUpdateWorker currently has the default priority of 2000. They should probably be higher priority than tasks like sending emails or executing herald rules.
Some context: we've had these tasks take longer to complete because the daemons were working through a backlog of emails and notifications they needed to send out. Is there a way for us to adjust this to our liking downstream? Or is there an upstream change that would make sense here?
Did you experience these issues after D16585? My expectation is that it should be almost impossible for PhabricatorRepositoryCommitHeraldWorker tasks to stall the queue for other priority-2000 tasks after that change.
Nope we don't have that integrated in yet (just missed our last cutoff). Once we get that pulled in I'll confirm it clears up the issue.
That change doesn't specifically do anything about mail tasks, but assuming they were coming out of repository imports it should probably clear them up too. I'd expect queue behavior to generally be more reasonable around repository imports once you pick up those changes.
Presuming this is resolved since it hasn't been updated in about a month, but let us know if it's still an issue after the update.