MyISAM? Or InnoDB? Lock_time perhaps applies only to table locks on MyISAM.
SHOW ENGINE InnoDB STATUS; You may find some deadlocks. Is Replication involved? Anyone doing an ALTER? > -----Original Message----- > From: Robinson, Eric [mailto:eric.robin...@psmnv.com] > Sent: Thursday, May 09, 2013 1:58 PM > To: mysql@lists.mysql.com > Subject: Slow Response -- What Does This Sound Like to You? > > We have a situation where users complain that the system periodically > freezes for 30-90 seconds. We check the slow query logs and find that > one user issued a complex query that did indeed take 30-90 seconds to > complete. However, NO slow queries are recorded for the other 50 users, > before, during, or after the freeze. Note that the complex query in > question always shows: "Lock_time: 0". > > Q: What conditions could cause single query to lock up a database for a > while for all users (even though it shows "lock time: 0") but no other > slow queries would show in the logs for any other users who are hitting > the database at the same time? > > OS: RHEL3 x64 > CPU: 8 x 2.9GHz Xeon > RAM: 32GB > Disk: RAID 5 (6 x 512GB SSD) > MySQL: 5.0.95 x64 > Engine: MyISAM > > -- > Eric Robinson > > > > > > > > Disclaimer - May 9, 2013 > This email and any files transmitted with it are confidential and > intended solely for mysql@lists.mysql.com. If you are not the named > addressee you should not disseminate, distribute, copy or alter this > email. Any views or opinions presented in this email are solely those > of the author and might not represent those of Physicians' Managed Care > or Physician Select Management. Warning: Although Physicians' Managed > Care or Physician Select Management has taken reasonable precautions to > ensure no viruses are present in this email, the company cannot accept > responsibility for any loss or damage arising from the use of this > email or attachments. > This disclaimer was added by Policy Patrol: > http://www.policypatrol.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
