This page explains what it means when you encounter a MySQL authentication issue such as the following:
MySQL connections: Error checking value of threads_connected: ERROR 2013 (HY000): Lost connection to MySQL server at 'sending authentication information', system error: 32
This error message is most commonly encountered on MySQL 5.0 where the authentication timeout defaults to 5 seconds. Typically, this issue is caused by the database being under heavy load or having constrained resources such as with SOLO or Small instances and not being able to complete authentication on a new connection in a timely fashion. Our typical recommendation for this issue is to review system resources and determine if database tuning or a larger instance may be necessary.