Yesterday at around 2am, I noticed one of my sites froze up and stayed that way for 15 minutes or more. It had 503 errors and then later 500 errors. I tried restarting my Web VPS and that didn’t work. Suddenly all my sites went down. I visited one of smaller sites in my web browser and it had a MySQL “too many connections” error displayed. It was only then that I decided to also restart my MySQL VPS server and that seemed to fix the issue. This appears to be a rare one time thing, possibly a DDOS attack with all the connections maxed out?
Question: If my site freezes up on VPS (or DreamCompute in the future), where do I find the cause through Linux command line? Is there a particular log or diagnostic script somewhere that tells me the reason why a site is frozen? It is extremely important for me to not be in the dark if I have to manage my own server on DreamCompute, so I would like to learn how to go about this if it happens again in the future… Like how would Dreamhost figure out what happened and how to fix it if I had written a message to customer support?