Lost connection to MySQL server while "reading source communication packet", system error: 113

Question

In my application, I recently received the above error message. I looked on the Internet for solutions, but did not come up with anything. The main problem is that this error occurs after about 1000 connections to the database, so 1000 connections without problems, and then this error, etc.

Based on this, all problems regarding iptables, firewall, etc., cannot be a problem, because everything works fine normally. Another reliable observation is that the error started about two weeks ago without any changes in the speed of crawling the application / access / google. Now there is a mistake and does not want to leave!;)

Could this be an indicator of a hardware problem? What does system error 113 mean (because I found many of these problems with error code 111)? Is there any meaningful hint on how I can reproduce / debug the error?

Regards

Ulf

Answer 1

I had a very similar problem with yours where I would get this error in rare cases (usually caused by scanning bots on the site) Look at the MySQL server variables:

wait_timeout
max_connections

Limit wait_timeout and / or increase max_connections.

See: max_connections and wait_timeout .