EmergencyEMERGENCY? Get 24/7 Help Now!

Mess with innodb_thread_concurrency


Posted on:

|

By:


PREVIOUS POST
NEXT POST
Share Button
In MySQL 5.0.19 the meaning of innodb_thread_concurrency variable was changed (yeah, again).
Now innodb_thread_concurrency=0 means unlimitied count of concurrent threads inside InnoDB. It’s logical, but there was long way. In MySQL versions below 5.0.8 for unlimited threads you had to set innodb_thread_concurrency over 500 (and default value for innodb_thread_concurrency was 8 ).
Starting with MySQL 5.0.8, the default value is 20, and concurrency checking will be disabled if the setting is greater than or equal to 20. But due to different bugs, in 5.0.19 the default value is 8 again, and 0 disables concurrency checking.
So if you used innodb_thread_concurrency over 500 (or default value in 5.0.8-5.0.18), don’t forget to change it to 0 in new versions, otherwise you can experience leaps of performance.
Share Button
PREVIOUS POST
NEXT POST


Vadim Tkachenko

Vadim leads Percona's development group, which produces the Percona Server, Percona Server for MongoDB, Percona XtraDB Cluster and Percona XtraBackup. He is an expert in solid-state storage, and has helped many hardware and software providers succeed in the MySQL market.



Tags:

, , , , ,

Categories:
Insight for DBAs


Percona’s widely read Percona Data Performance blog highlights our expertise in enterprise-class software, support, consulting and managed services solutions for both MySQL® and MongoDB® across traditional and cloud-based platforms. The decades of experience represented by our consultants is found daily in numerous and relevant blog posts.

Besides specific database help, the blog also provides notices on upcoming events and webinars.

Want to get weekly updates listing the latest blog posts? Subscribe to our blog now! Submit your email address below.

No, thank you. Please do not ask me again.