Merge request is not mergeable


Was looking to see if anyone has come across this error from the sidekiq logs.

{"severity":"ERROR","time":"2022-05-12T16:41:38.662Z","worker":"MergeRequestMergeabilityCheckWorker","message":"Failed to check mergeability of merge request: Failed to obtain a lock","merge_request_id":2957,"retry":0}
{"severity":"ERROR","time":"2022-05-12T16:46:06.643Z","worker":"MergeRequestMergeabilityCheckWorker","message":"Failed to check mergeability of merge request: Merge request is not mergeable","merge_request_id":2958,"retry":0}

We’ve been seeing this error on and off. Sometimes it prevents the merge of an MR with

The source branch xxx does not exist. Please restore it or use a different source branch.

Sometimes additional commits will not automatically be added to a merge request. We are unable to reproduce the error consistently. We are running an omnibus installation on AWS EC2 on a m5.xlarge with about 20 users. Gitlab version 14.8.5-ee. We started seeing these errors after our upgrade.

Has anyone seen this? The only issues I can find on the issue tracker were for the non self hosted version of gitlab during an incident with their infra. Our solution to currently resolve this is to restart gitlab via the cli with a sudo gitlab-ctl restart .