On 07/06/2012 12:45 PM, Steven Cassidy wrote: > Hi, Thanks for the replies. I don't think there's a leak unless it > manifests itself only very occasionally. The stats now are Active 6, > Idle 133, Created 0.02% (757 / 3.3M), Failed 0, max-connections 256, > idle time 30000. The active count is not increasing. > > The driver type in the pool definition is > com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource. The > connector/j version is mysql-connector-java-5.0.8-bin.jar. I'm > interested that you mention a known issue with mysql - could we be > seeing that possibly? Is there a fix, or somewhere I can learn about > the issue?
The ConnectionPoolDataSource is at http://wiki4.caucho.com/Application_Server:_MySql_JDBC_Pooling and http://bugs.caucho.com/view.php?id=4734. But if you don't have any threads waiting for a new connection in the driver (there should be at least one), it might be a different issue, and may be fixed in a later Resin version. -- Scott > > The puzzling thing is that as far as I can see from the thread lists, > when these freezes happen, there is no runnable thread in any of our > code at all - just the threads waiting on the lock. MySQL show > processlist also claims its idle. > > Thanks again. > Steven > > > On 6 July 2012 14:59, Scott Ferguson <[email protected]> wrote: >> On 07/06/2012 11:47 AM, Knut Forkalsrud wrote: >> >> You may want to keep track of the DB pool statistics. Active versus maximum >> allocation counts. If this is a connection leak you would notice the number >> of active connection creeping upwards until it reaches max and your freezing >> symptoms appear. >> >> >> Also, which driver is this with? There's a specific synchronization problem >> with the mysql ConnectionPool driver that might be a problem. >> >> And, for jstack, the thread that owns the lock/counter is more important >> than the threads waiting. If you can find the threads that are opening the >> connection (in the actual driver code), that would help track this down. >> >> An upgrade might help, but it would depend on what's causing the problem. >> >> -- Scott >> >> >> Knut Forkalsrud >> >> >> >> On Fri, Jul 6, 2012 at 5:51 AM, Steven Cassidy <[email protected]> >> wrote: >>> Hi, I'm using resin-3.1.3 on a busy site. Periodically the site >>> freezes. A jstack on the server shows most threads in this state: >>> >>> java.lang.Thread.State: TIMED_WAITING (on object monitor) >>> at java.lang.Object.wait(Native Method) >>> at com.caucho.jca.ConnectionPool.create(ConnectionPool.java:897) >>> - locked <0x00002aaaba60be48> (a java.util.ArrayList) >>> at com.caucho.jca.ConnectionPool.allocatePool(ConnectionPool.java:779) >>> at com.caucho.jca.ConnectionPool.allocate(ConnectionPool.java:740) >>> at >>> com.caucho.jca.ConnectionPool.allocateConnection(ConnectionPool.java:551) >>> at com.caucho.sql.DataSourceImpl.getConnection(DataSourceImpl.java:65) >>> at com.caucho.sql.DBPool.getConnection(DBPool.java:669) >>> >>> It looks like no thread ever gets notified and all wait indefinitely. >>> Resin generally restarts itself about 15 minutes later if left alone. >>> The database itself apppears idle during this time. >>> >>> I wondered if this might be a known problem and if upgrading to 3.1.12 >>> would help? I don't think the pool is full. I noticed a pool timing >>> issue was fixed in 3.1.10 (bug 3837) and the implementation of the >>> allocate method changed, but that wasn't directly related to freezing. >>> Perhaps we should just try it and see, but I figured I'd ask if this >>> was noted / known behavior. >>> >>> Many thanks, >>> Steven >>> >>> _______________________________________________ >>> resin-interest mailing list >>> [email protected] >>> http://maillist.caucho.com/mailman/listinfo/resin-interest >> >> >> >> _______________________________________________ >> resin-interest mailing list >> [email protected] >> http://maillist.caucho.com/mailman/listinfo/resin-interest >> >> >> >> >> _______________________________________________ >> resin-interest mailing list >> [email protected] >> http://maillist.caucho.com/mailman/listinfo/resin-interest >> > _______________________________________________ > resin-interest mailing list > [email protected] > http://maillist.caucho.com/mailman/listinfo/resin-interest > _______________________________________________ resin-interest mailing list [email protected] http://maillist.caucho.com/mailman/listinfo/resin-interest
