Gary - is there any way to check how many concurrent connections you have per second out of those 14,000 users?
IIRC, each table requires at least one file handle to open the table's data file (.MYD), plus 1 more for the index file (.MYI) if the index file is updated. So, I'm wondering if you are running out of file handles, which would make mysql wait untill there are enough file handles free, for mysql to do it's job. <quote> open_files_limit The number of files that the operating system allows mysqld to open. This is the real value allowed by the system and might be different from the value you gave mysqld as a startup option. The value is 0 on systems where MySQL can't change the number of open files. </quote> mysql> show variables like "open%"; +------------------+-------+ | Variable_name | Value | +------------------+-------+ | open_files_limit | 1024 | +------------------+-------+ 1 row in set (0.00 sec) mysql> show status like "open%"; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Open_files | 44 | | Open_streams | 0 | | Open_tables | 20 | | Opened_tables | 0 | +---------------+-------+ 4 rows in set (0.00 sec) What does this return on your system? If this is the case, then I can't see how running multiple mysql servers will help. Keith On Sun, 2 Apr 2006, Alexey Polyakov wrote: > To: [EMAIL PROTECTED] > From: Alexey Polyakov <[EMAIL PROTECTED]> > Subject: Re: Tuning a Server with >10,000 databases > > On 4/1/06, Greg Whalin <[EMAIL PROTECTED]> wrote: > > > Not necessarily sure this is the problem. But if it is, it could be > > solved by switching to a different filesystem. Or, if you are using > > ext3fs, you could try enabling dir_index on the filesystem (tune2fs -O > > dir_index ... man tune2fs), which could give you a boost in performance > > in a large dir (this could take a long time to complete). You may also > > want to up your table cache so that mysql can keep more of your commonly > > used tables open? > > FWIW, I've experimented heavily with FS options, and found out that > dir_index on ext3 doesn't help at all, it actually harms performance. > 'noatime' and 'nodiratime' options do help a little. > Also, 14000 subdirectories is not something that will cause 15 seconds > delay - those 14000 subdirectories will always live in OS dentry cache > anyway. > > > -- > Alexey Polyakov > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
