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
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 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.
On 6 July 2012 14:59, Scott Ferguson <f...@caucho.com> 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 <steven.cass...@gmail.com>
>> 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.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,
>> resin-interest mailing list
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