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From:Adam Nelson Date:December 4 2002 9:36pm
Subject:RE: Slow performance using 3.23 on RH 8.0
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Oh, and what's up with the thread_concurrency being 6?  That doesn't
make any sense unless you have a tri-processor setup.

> -----Original Message-----
> From: Ledet, Mike [mailto:MLedet@stripped] 
> Sent: Wednesday, December 04, 2002 11:01 AM
> To: 'mysql@stripped'
> 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
> 
> 
> 

Thread
Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Nikolas Samios4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Mirek Novak5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • Re: Slow performance using 3.23 on RH 8.0Michael T. Babcock5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
    • Re: Slow performance using 3.23 on RH 8.0Jeremy Zawodny5 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
  • RE: Slow performance using 3.23 on RH 8.0Adam Nelson4 Dec
RE: Slow performance using 3.23 on RH 8.0Mike Ledet4 Dec
RE: Slow performance using 3.23 on RH 8.0Jan Steinman5 Dec