Mysql show processlist lists many processes sleep and info = null?

Question

I\'m injecting a stress test into my web app that connects to a mysql server and I\'m monitoring the show processlist of mysql.

When the load is high (high swap i/o)

Answer 1

Those are idle connections being held by a client. You should make sure that whatever client library you are using (JDBC, ...) is configured to not keep unused connections open so long, or that your # clients * max # of connections isn't too big.