We've just upgraded our existing MySQL5.1 DB servers to newer (much better) hardware with MySQL 5.5, and things have been going mostly smoothly for almost 6 weeks.
Just the last few days, I've noticed a few errors, such as:
From a MySQL Slave:
[ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)
Or From Apache/Other:
Lost connection to MySQL server at 'reading initial communication packet', system error: 110
At one point this evening, many webnodes reported this error for a three minute period (many such reports as this was in a busy period). However, the issues don't appear to correspond with any times of extreme load. For all intents and purposes, the connection/thread load on MySQL is at a normal rate (between about 10 and 40 connected threads), and Web load has been a LOT higher at times over the last few weeks.
Could there bee other reasons for these connection errors, that I'm not seeing?