Slow reaction & MySql restarts

hello everybody,

I’ve been dealing with this problem for three days (all day long ) now, so it’s really driving me crazy…

I work for a little web-development company with some hosting services, mostly to those clients who have purchased our portal engine. A few days ago a very strange problem arose…

We host around 40-50 portals (little one’s, only with few hundred visitors per day) and one of them became nearly unreachable. It means that most of the queries are running for 40-50 secs. We are using only MyIsam tables. The biggest (with the most queries, but really simple one’s without any join’s) is 34 Mb with around ~11 k rows. It was running smoothly without any problems till last friday.

First I thought that the table became corrupted so I repaired and optimized it. => No improvement

Copied the database to another location on the server (thought that maybe we have a hardware error, and it’s not accessible)
=> No improvement

We had 4 indexed fields, so I simply deleted one (the date field’s index) => Improved a lot for some time, then it became worse

Finally I simply truncated the database to around ~1k rows => Slight improvement… (

Since this problem the mysql daemon sometimes simply stops so I have to restart it… can’t find any useable info in the logs about this (

The funny thing is that the other portal’s are running fine, although some of them has more records than this one. (the engine behind is the same - developed by us in PHP)

My last guess is a hardware error, but after running some diagnostics, everything is looking fine… :S

Any idea’s and questions are warmly welcome!

Thank you in advance,

Summary of what I’ve tried

  1. Repair & optimize table
  2. Copy the whole database to a new one and use that one
  3. “Played” with the indexes
  4. Truncated the database

Make better use of indices, no doubt. I could take a look for you at a modest fee, pm in case you want me to.

Else just dump your worst queries here plus explain output.