MySQL slowness

MySQL slowness

Posted by: zylox
Posted on: 2007-07-31 15:09:00

Hi!

I'm still wondering why MySQL is so slow over here at DH. The server my sites are on is fast, some scripts (PHP and CGI) which don't use MySQL run very fast actually.

Looking at the queries sent to the MySQL server here at DH I see around 17-20 queries/second on the MySQL server I'm on (Arlene) and it's responding very slow. I just checked at two other hosts where I'm hosting and where MySQL is really fast (Gallery 2 with over 7000 high resolution images for example loads instantly on both hosts). The query count on one of those servers is around 100 queries/second (that being a dedicated MySQL server) and the other server has around 25-30 queries/second (web-, mail-, ftp-, mysql-server run on the same server).

So why is DH MySQL so slow, even though it has the lowest query/second count?

Any ideas?

Re: MySQL slowness

Posted by: jusone
Posted on: 2007-08-06 14:34:00

I am seeing similar slowness. Is there a way to see the mysql error and slow query logs? Any advice on this would be appreciated.

Re: MySQL slowness

Posted by: zylox
Posted on: 2007-08-07 07:23:00

Just recently I found another MySQL server which has 300 queries/seconds and runs very fast, much faster than the MySQL I'm on here. That server runs on a P IV, 3ghz with 4GB of ram. So either the MySQL Server I'm on over here at DH is a Pentium 100 with 32mb ram which can't handle 15 queries /second or something else has to be wrong.

On another note, why still MySQL 5.0.2x ? MySQL 5.0.45 is a major security release and considering that DH allows external connections to the server I would expect it to get updated. A DH employee told me that PHP would get updated to 5.2.3 back in June. It's still not updated. :(

Re: MySQL slowness

Posted by: jusone
Posted on: 2007-08-07 15:48:00

Wow, too bad there hasnt been any input on this. Seems like something DH would care to comment on? I'm sure were not the only ones seeing poor mysql performance...

Re: MySQL slowness

Posted by: rlparker
Posted on: 2007-08-07 15:58:00

In reply to:

Wow, too bad there hasnt been any input on this. Seems like something DH would care to comment on?


DreamHost staff does occasionally comment on threads in these forums, but not on a regular basis, so you may have a bit of wait for a "DreamHost Staff" response to come (if it does at all wink).

There are *lots* of threads discussing the nuances of MySQL on Dreamhost (just search for "mysql slow" - without the quotes and selecting the "and" option).

I feel that part of the problem is that MySQL queries on DreamHost have to make "that trip" from the webserver through the DH network to the MySQL server, and back again. The potential for bottlenecks in this, combined with NFS storage, has got to a challenge to manage.

--rlparker

Re: MySQL slowness

Posted by: anonymous2
Posted on: 2007-08-08 15:07:00

http://www.dreamhoststatus.com/2007/08/07/mysql-on-dedicated-servers/

There was some mysql problems on dedicated servers. Coincidence? wink

I agree about the network issues, although DreamHost says they're fast...

Tags: mysql servermailqueriesdhscriptsservers