In a multi-configuration job, all the builds in all configurations just disappeared. The job itself still has some history of builds, but the individual configurations are gone.

The directory $JENKINS_HOME/jobs/JobName/configurations/axis-X/value/builds only contains the {{last*} files, but no builds. This is why I think it's separate issue from JENKINS-15156 where the comments indicate the data are intact on disk. In my case they are not.

The job has deleting old builds configured. The builds were not old by the criteria (configured to keep builds for 14 days, the last build was at most 2 days old when it disappeared).

The problem occured once already, but it was few months ago. I could try enabling some logging so something could be found when it happens next time, but I don't know what.

Currently the only thing I see in the main log that mentions the build in question is a log message Started Out of order build detection followed by bunch of failed attempts to read logs of builds that were legitimately deleted ages ago.