On 04/16/2015 09:54 AM, Sean Dague wrote:
On 04/16/2015 05:20 PM, Qiming Teng wrote:Wondering if there is something misconfigured in my devstack environment, which was reinstalled on RHEL7 about 10 days ago. I'm often running into mysql connections problem as shown below: $ mysql ERROR 1040 (HY000): Too many connections When I try dump the mysql connection list, I'm getting the followng result after a 'systemctl restart mariadb.service': $ mysqladmin processlist | grep nova | wc -l 125 Most of the connections are at Sleep status: $ mysqladmin processlist | grep nova | grep Sleep | wc -l 123 As for the workload, I'm currently only running two VMs in a multi-host devstack environment. So, my questions: - Why do we have so many mysql connections from nova? - Is it possible this is caused some misconfigurations? - 125 connections in such a toy setup is insane, any hints on nailing down the connections to the responsible nova components? Thanks. Regards, QimingNo, that's about right. It's 1 connection per worker. By default most daemons start 1 worker per processor. Each OpenStack service has a bunch of daemons. It all adds up pretty quick.
And just to add to what Sean says above, there's nothing inherently wrong with sleeping connections to MySQL. What *is* wrong, however, is that the default max_connections setting in my.cnf is 150. :( I frequently recommend upping that to 2000 or more on any modern hardware or decent sized VM.
Best, -jay __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: [email protected]?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
