I'm having a weird issue on an EC2 instance on AWS. On this instance, we have a Node.js application that jam the SSH server. When we stop this application, we are unable to connect over SSH to this instance during approximately a minute.
The application is a simple webapp build with express but nothing related to SSH, not even a database connection. The load of the server is low (0.35 for two cores) and the RAM is 50% filled.
I've absolutely zero clue which tool or approach to use to find the root cause of this problem. So, if you have some tips on how to debug an SSH server, they are welcomed.