I tried your TOP suggestion but didn't see anything out of the ordinary. Swap size was constant (6400 or so) and didn't increase or decrease under load.
I'll try the swap-off idea when I get a chance. -----Original Message----- From: Nikolas Samios [mailto:[EMAIL PROTECTED]] Sent: Wednesday, December 04, 2002 3:37 PM To: Ledet, Mike; [EMAIL PROTECTED] Subject: Re: Slow performance using 3.23 on RH 8.0 Hi Mike, i'm a newbie in optimizing the inner structure of a db - so i stick to the os-part where i might have a vague clue ;-) did you take a look at the memory / swap-space mysqld used when doing the query? (maybe use TOP (add swap to the view by hitting "f" and then "o"), look at the swapspace used by the mysqld threads, usage of kswapd, loadaverage...) I once had a lot of performance problems with mysqld 3.23.4x on suse-linux 7 when suddenly the os startet to assign hd-swap-space to some of the mysqld threads, which slowed down the action dramatically. changing my.cnf didn't really change the situation - but for testing you could just do "swapoff -a" and compare the results. goodluck, niko ----- Original Message ----- From: "Ledet, Mike" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, December 04, 2002 5:00 PM Subject: Slow performance using 3.23 on RH 8.0 > I'm running Mysql 3.23.52 on a Redhat 8.0 installation booting to Gnome. > The machine is a dual AMD 1800, 1 gig of ram, one Ultra ATA IDE drive, and 2 > 18 gig scsi 10,000 RPM drives on a RAID controller running Raid 0. > > I've got everything except /db on the IDE drive, /db is the only thing on > the raid array. > > I've got a couple of smallish tables and one larger table with about 7 gigs > of data. The larger table is a fixed row format table with each row being > 462 bytes wide. I have a primary auto increment int column and a unique > index on a varchar 60. Pack keys is off, delayed key writes on. > > With this kind of hardware I was expecting pretty good performance, but I > haven't seen it yet. I finally decided something was wrong when I had to > run an alter table on the 7 gig table, adding 3 columns, a varchar 12, a > varchar 50, and a datetime columm.... and it took over 10 HOURS to complete. > > That seems way too slow to me... > > I've included relevant portions (the uncommented portions) from my.cnf, the > OS installation was fairly vanilla, using defaults for just about > everything. The file system is ext3. > > Any suggestions or things I haven't included that you need? Sorry if I'm > doing something really stupid here... relatively new to Linux after a lot of > years of windoze. > > Thanks in advance > > Mike > > ********** my.cnf ************* > > [mysqld] > port = 3306 > socket = /var/lib/mysql/mysql.sock > datadir = /db/mysql > skip-locking > set-variable = key_buffer=500M > set-variable = max_allowed_packet=2M > set-variable = table_cache=512 > set-variable = sort_buffer=22M > set-variable = record_buffer=22M > set-variable = thread_cache=8 > # Try number of CPU's*2 for thread_concurrency > set-variable = thread_concurrency=6 > set-variable = myisam_sort_buffer_size=64M > log-bin > server-id = 0 > tmpdir = /tmp/ > [mysqldump] > quick > set-variable = max_allowed_packet=16M > > [mysql] > no-auto-rehash > # Remove the next comment character if you are not familiar with SQL > #safe-updates > > [isamchk] > set-variable = key_buffer=500M > set-variable = sort_buffer=8M > set-variable = read_buffer=10M > set-variable = write_buffer=30M > > [myisamchk] > set-variable = key_buffer=500M > set-variable = sort_buffer=8M > set-variable = read_buffer=10M > set-variable = write_buffer=30M > [mysqlhotcopy] > interactive-timeout > > > > --------------------------------------------------------------------- > 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 --------------------------------------------------------------------- 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
