FreeBSD MySQL still WAY slower than Linux

[Nick Evans]

Update:

Switched threading libraries from libpthread to libthr and now I'm getting
27,500 selects/sec at 45% idle. This is with version 4.1.12 of mysql using
myISAM tables compiled with the following options

WITHOUT_INNODB
BUILD_OPTIMIZED

relevant parts of my.cnf:

# The MySQL server
[mysqld]
port            = 3306
socket          = /tmp/mysql.sock
skip-locking
key_buffer = 384M
max_allowed_packet = 1M
table_cache = 512
sort_buffer_size = 16M
read_buffer_size = 16M
read_rnd_buffer_size = 16M
myisam_sort_buffer_size = 96M
thread_cache = 8
query_cache_size = 64M
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 8

# max conns
max_connections=8000




On Wed, 29 Jun 2005 17:00:44 -0400
Nick Evans <nevans at talkpoint.com> wrote:

> I just tried this on my dual opteron test rig and didn't notice a difference
> in performance with noatime set. What did make a difference was moving from
> fxp to bge network cards. bge supports checksum offloading where fxp only
> supports interrupt bundling. Freed up another 20% idle during my test runs.
> I'm now hitting ~23,000 selects/sec, ~42% idle when running select-key.smack
> from 3 client hosts. If we establish a suitable test mix and distribute the
> smack/data files at least we can get consistent test results across systems.
> 
> Nick 
> 
> 6-CURRENT as of Jun 27th
> Dual Opteron 246
> Tyan K8SD Thunder Pro
> 4GB RAM
> my-huge.cnf with tweaks.
> 
> 
> On Wed, 29 Jun 2005 11:45:33 +0200
> Jeremie Le Hen <jeremie at le-hen.org> wrote:
> 
> > Hi Michael, hi Steve,
> > 
> > > For me this is as fast as I need my database to be but I can understand 
> > > there is a difference here between FreeBSD and Linux that would make
> > > you prefer it as the db OS choice.
> > 
> > Could you try mounting the filesystem where the database lives with
> > the noatime option, and re-run your tests ?  IIRC from previous threads
> > on this subject, Linux doesn't really honor this while FreeBSD does,
> > which pulls down the performances.
> > 
> > Regards,
> > -- 
> > Jeremie Le Hen
> > < jeremie at le-hen dot org >< ttz at chchile dot org >
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