Gitlab responds too slow sometimes 502 error

We are new to GitLab we just started with self-hosted GitLab on a docker container on a centos VM. Till yesterday everything was working fine but then Gitlab started responding too slow and sometimes we get error 502. We are not more than 10 users with only 1-2 users connected at a time.

The VM configuration is more than the recommended requirements but I am not able to figure out what the issue is. These are the VM configurations we are using:

  • CentOS 7
  • RAM 12 GB
  • 8 Cores CPU
  • 100 GB HDD

Can anyone tell me how to troubleshoot the VM and see what is the issue? I have a very basic knowledge of Linux commands. I read about the unicorn workers that it can increase the response time. Should I change the number from 2 to any other number based on the above settings? Or should leave it as it is?