MySQL Forums
Forum List  »  Performance

Re: mysql 5.5.9 dreadfully slow
Posted by: Rick James
Date: February 21, 2011 05:51PM

innodb_buffer_pool_size (5.1->5.5): 260MB->100MB -- probably not significant, but could be.
sync_binlog: off -- no impact
innodb_doublewrite -- ON in both
trx_commit -- 1 in both
log file/buffer sizes -- bigger; seems like that would not hurt.
io_tickets -- bigger, so 5.5 should be able to handle more traffic.
max_dirty_page_pct -- 90% -> 75% -- a big change, but can't imagine that it would cause your problem.
sync_spin_lock_loops -- 20->30 ?

key_buffer_size -- 16MB -> 55MB -- might help if you have large MyISAM indexes

general_log -- ON -> OFF -- ?? ON would have slowed down 5.1 ??
log_bin -- Ditto ??

show STATUS like 'Qc%'

Do SHOW CREATE TABLE on both 5.1 and 5.5. I would like to know the Engine, and would like to know if it was the same engine on both.

4GB of RAM on 5.5; how much on 5.1? None of the settings seem too large for a 4GB machine.

VMs can have a large overhead for I/O -- were either of your timings on a VM?

I see no clues that could explain a 60x performance difference.

Recommend you post your stored procedure and accompanying data on Be sure to specify whether it is MyISAM or InnoDB.

Options: ReplyQuote

Written By
February 20, 2011 11:33AM
February 21, 2011 01:39PM
February 21, 2011 04:21PM
Re: mysql 5.5.9 dreadfully slow
February 21, 2011 05:51PM
February 21, 2011 07:44PM

Sorry, you can't reply to this topic. It has been closed.
This forum is currently read only. You can not log in or make any changes. This is a temporary situation.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.