[JENKINS-33875] Gerrit trigger threads blocked (GerritMissedEventPlaybackManager ?)

We are having problems with Gerrit triggers locking up and builds not triggering. I've attached a thread dump which shows 2 of the 3 Gerrit trigger threads blocked waiting on locks held by the 3rd thread. This seems to be related to the event playback support, which we have just disabled to (hopefully) avoid this.

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Originally reported by wsaxon, imported from: Gerrit trigger threads blocked (GerritMissedEventPlaybackManager ?)

• assignee: rsandell
  
• status: Open
  
• priority: Major
  
• component(s): gerrit-trigger-plugin
  
• resolution: Unresolved
  
• votes: 0
  
• watchers: 2
  
• imported: 2025-12-06
  

Raw content of original issue

We are having problems with Gerrit triggers locking up and builds not triggering. I've attached a thread dump which shows 2 of the 3 Gerrit trigger threads blocked waiting on locks held by the 3rd thread. This seems to be related to the event playback support, which we have just disabled to (hopefully) avoid this.

• environment: Ubuntu 14.04.4, Oracle JDK 1.8.0_74, Jenkins 1.642.3, Gerrit Trigger 2.18.4, Gerrit 2.12.2 w/ events-log v2.12-92-g048170a-dirty

2 attachments

- [Gerrit-threads-blocked.txt](https://issues.jenkins.io/secure/attachment/32307/Gerrit-threads-blocked.txt)
- [Gerrit-threads-locked-noevents-log.txt](https://issues.jenkins.io/secure/attachment/32366/Gerrit-threads-locked-noevents-log.txt)

Start with the attached Gerrit-threads-blocked.txt and Gerrit-threads-locked-noevents-log.txt dumps, then inspect the GerritMissedEventPlaybackManager and event playback path mentioned in the report. Compare the locks held by the three Gerrit trigger threads and determine why builds stop triggering. Done means the blocking condition is addressed and Gerrit triggers continue to launch builds with event playback enabled.

Written by the indexing model from the issue text.