Greetings,
I've been running a public MySQL server for a couple of years that now
supports several thousand users. I used to run this on a lowly PII-350 and
it ran quite fine with CPU loads usually hanging well under 0.20. The only
hitch was the time necessary to connect seemed to jump up to a few seconds
when the number of databases exceeded 2000 or so. It appeared to not be
linear, performance was "good" below 2000 databases and the connection time
went to a couple of seconds (as measured by a trivial php page that makes a
connection).
I suspected that the connection speed was an ext2 filesystem bottleneck
when it had to deal with the large number of files in the mysql data
directory.
I modernised a few months ago to an athlon 1.3GHz with the same ram and
a faster hard drive. I also upgraded to Linux 7.3 using an ext3 filesystem.
I thought that ext3 might handle a large number of files better, and I also
thought that the faster box and newer kernel would allow me to have more
databases on one server without suffering the same connection speed penalty.
However, I seem to have hit this same wall at roughly the same number of DBs
(closer to 3000 this time)
To summarize, it appears to me that there is a reasonable upper bound on
the number of databases without suffering connection performance, probably
limited by the filesystem.
My questions are 1) Are these observations expected? (I was a bit
disappointed that the new box didn't perform better...the cpu load is
usually idle) 2) Is there a way to mitigate this at the linux admin
level? (kernel parameters? ext3 parameters? change to reiserfs? 3)
Finally, are there MySQL parameters that can be tuned to enhance performance
for a large number of databases (note, not concurrent users...that is a
small number)
Regards,
Gary "SuperID" Huntress
=======================================================
FreeSQL.org offering free database hosting to developers
Visit http://www.freesql.org
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
