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From:Ware Adams Date:July 19 2004 8:39pm
Subject:Re: InnoDB my.cnf settings on OS X 10.3 Server?
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Kieran Kelleher wrote:

>Does anyone out there have a suggested innodb parameters or even a 
>working set of params that I could start with.

The InnoDB manual gives good suggestion. Some minor comments (none
particularly OS X specific, but InnoDB works fine on it)

innodb_buffer_pool_size is very important.  We have ours at 900 MB, but
this is a machine running only mysql with 2GB of RAM.  You want as much
as you can have here, but not so much to cause pageing.

innodb_additional_mem_pool_size should be big enough to work around this
bug (we use 50M and have avoided the bug, 10M did not, but it's usage
specific)

http://dev.mysql.com/doc/mysql/en/InnoDB_news-4.0.21.html

>If you configure innodb_additional_mem_pool_size so small that InnoDB
>memory allocation spills over from it, then every 4 billionth spill
>may cause memory corruption. A symptom is a printout like below in the
>`.err' log. The workaround is to make innodb_additional_mem_pool_size
>big enough to hold all memory allocation. Use SHOW INNODB STATUS to
>determine that there is plenty of free space available in the
>additional mem pool, and the total allocated memory stays rather
>constant.
>InnoDB: Error: Mem area size is 0. Possibly a memory overrun of the
>InnoDB: previous allocated area!
>InnoDB: Apparent memory corruption: mem dump  len 500; hex

when we set innodb_thread_concurrency too large we ran into behavior
that looked a lot like a thread thrashing problem seen on InnoDB on
Linux some time ago.  We didn't have proof, but reducing
innodb_thread_concurrency to (number of cpus + number of physical disks)
made the issue go away.  For us this value is 8.

We use 4 logs and a log file size about 25% of innodb_buffer_pool_size.
(set via innodb_log_file_size and innodb_log_files_in_group).  This has
implications for speed and recovery time after a crash.

>
>Also, does anyone definitively know what the maximum filesize is for OS 
>X Panther (and consequently the max innodb tablespace filesize?

It's huge.  We use mainlu 4G files, but an autoextending one grew to
12GB without issue.  Apple lists this in the knowledge base somewhere.

Good luck,
Ware
Thread
InnoDB my.cnf settings on OS X 10.3 Server?Kieran Kelleher19 Jul
  • Re: InnoDB my.cnf settings on OS X 10.3 Server?Ware Adams19 Jul
  • RE: InnoDB my.cnf settings on OS X 10.3 Server?Lachlan Mulcahy20 Jul