tree 87044b13b30b877e648021093fe9656fa1bf2135
parent 37ad7ce16bbcd6bca746a6abb0e6f57fb63e9124
author Marcin Czech <maczech@gmail.com> 1706862783 +0100
committer Marcin Czech <maczech@gmail.com> 1708937360 +0100

Avoid duplicate indexing tasks for the same id

Indexing tasks check if all necessary data is present on the node
by comparing the event timestamp and the event target sha1 with the
local repository sha1. For very active repositories, some of the
indexing tasks never pass this check because:

* During the retry backoff, the target branch of the change was
updated to a newer sha1
* The consumed event is pointing to an outdated `/meta`
NoteDb version.

This means that we can end up with multiple indexing tasks trying to
reindex the same change, some of them except the last one will fail
after the maximum number of retries.

To avoid this situation, make sure that:

* There is only one pending indexing task trying to index a change.
* If any indexing task successfully indexed a change, the previous
indexing task pending for that change can be discarded.

Bug: Issue 320542020
Change-Id: I0117676ed015209a6b39f05e296adf6caf8b4485