Gitlab (Omnibus) stuck with the merge requests

We are running Gitlab 10.7.3 version (I know a bit older version) but its was running fine for us since last 2 years until last few days where the Merge request is not working.
Symptom:
When we merge the request from one branch to another, the message appears “This merge request is in the process of being merged” and it stuck there … After a while (10-15 mins), the request times out and the Merge Button becomes active again.

I looked at the Gitlab Adminstration -> Background Jobs tab but couldn’t find any issue there (see attached screensot)

. The monitoring status also shows Healthy.

Please assist.

Thanks
Arun Gupta

I found that the sidekiq process in my screenshot above was in “stopping” status. Notice the text " [0 of 25 busy] stopping"
On restarting (Stop and Start) the Gitlab service, the sidekiq process was hung and I have to manually kill the process (Note: sending TTIN signal did not help i.e. kill -TTIN but kill -9 did help)

Issue resolved by following the step:

  1. Stop the Gitlab service (gitlab-ctl stop)
  2. Identify the sidekiq process id using command: ps -ef | grep -i ‘sidekiq’
  3. kill -9
  4. Start the Gitlab service (gitlab-ctl start)