Spike in MySQL incoming traffic

[Ellimist]

Hi,

I'm in no way a seasoned sysadmin, so please be nice. I was browsing through my Munin graphs when I noticed a huge spike (compared to normal traffic) in inbound MySQL traffic. Unfortunately, binary logs for MySQL were disabled, and I have no way of knowing which queries were ran. Here are the corresponding graphs -







The VPS runs a moderately busy forum and a custom PHP/flat file driven gallery (which doesn't connect to MySQL in any way). I have looked at the Nginx logs and everything seems innocuous.

How do I investigate this?

 

[Damian]

Since you don't have logs enabled, it's difficult to troubleshoot... if logs aren't enabled, then it truly doesn't log anything.

 

[Ellimist]

So, is it wise to enable MySQL query logging? Doesn't it affect performance? My tables are all MyISAM, if that's relevant in any way.