RE: Tomcat JDBC Connection Pool - Deadlock

2013-03-28 Thread Caldarale, Charles R 
 From: amit shah [mailto:amits...@gmail.com] 
 To: Tomcat Users List; d...@tomcat.apache.org

Do not cross-post.  This belongs only on the users list.  Read (and follow) the 
mailing list usage rules.

 Subject: Tomcat JDBC Connection Pool - Deadlock

 The two threads involved in the deadlock have the below traces 
 (from a thread dump)

You'll need to show the complete traces for both threads, not just the tail 
ends.

 - Chuck


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Re: Tomcat JDBC Connection Pool - Deadlock

2013-03-28 Thread amit shah 
I copied the dev group too since it involved technical details (thread
dumps, source code etc). Sorry if that sounds incorrect.

The traces I added are not incomplete. They are the ones we generated
through the jmx api
- ManagementFactory.getThreadMXBean().dumpAllThreads(true, true);


On Thu, Mar 28, 2013 at 6:21 PM, Caldarale, Charles R 
chuck.caldar...@unisys.com wrote:

  From: amit shah [mailto:amits...@gmail.com]
  To: Tomcat Users List; d...@tomcat.apache.org

 Do not cross-post.  This belongs only on the users list.  Read (and
 follow) the mailing list usage rules.

  Subject: Tomcat JDBC Connection Pool - Deadlock

  The two threads involved in the deadlock have the below traces
  (from a thread dump)

 You'll need to show the complete traces for both threads, not just the
 tail ends.

  - Chuck


 THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
 MATERIAL and is thus for use only by the intended recipient. If you
 received this in error, please contact the sender and delete the e-mail and
 its attachments from all computers.


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RE: Tomcat JDBC Connection Pool - Deadlock

2013-03-28 Thread Caldarale, Charles R 
 From: amit shah [mailto:amits...@gmail.com] 
 Subject: Re: Tomcat JDBC Connection Pool - Deadlock

 I copied the dev group too since it involved technical details (thread
 dumps, source code etc). Sorry if that sounds incorrect.

It was incorrect, as is your top-posting.  Don't do either.

 The traces I added are not incomplete.

Clearly they are incomplete, as evidenced by the ellipses after both fragments. 
 Use a more appropriate mechanism:

http://wiki.apache.org/tomcat/HowTo#How_do_I_obtain_a_thread_dump_of_my_running_webapp_.3F

 - Chuck


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Re: Tomcat JDBC Connection Pool - Deadlock

2013-03-28 Thread Daniel Mikusa 
On Mar 28, 2013, at 8:27 AM, amit shah wrote:

 Hello,
 I am using the tomcat jdbc connection pool independently in my web

Because you are using this independently you are going to need to tell us the 
version of the connection pool that you have included with your application.  
Also, a code snippet that shows how you setup the connection pool, we need to 
see what options that you have used.

 application which is deployed on glassfish web server. While performing a
 database operation,

What specifically are you doing in the application?  Can you include a code 
snippet?  In particular, we'd want to see how you are getting a connection, how 
its being used and how you are returning it to the pool.

 our application goes into a deadlock state.

How are you determining this?  What is the behavior that you see with your 
application?

Dan



 The two threads involved in the deadlock have the below traces (from a thread 
 dump)
 
 thread1 Id=534 WAITING on
 java.util.concurrent.locks.ReentrantReadWriteLock$FairSync@184ffd83 owned
 by thread2 Id=529
 at sun.misc.Unsafe.park(Native Method)
 -  waiting on
 java.util.concurrent.locks.ReentrantReadWriteLock$FairSync@184ffd83
 at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
 at
 java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(ReentrantReadWriteLock.java:945)
 at
 com.sun.ejb.containers.CMCSingletonContainer._getContext(CMCSingletonContainer.java:142)
 at com.sun.ejb.containers.BaseContainer.getContext(BaseContainer.java:2528)
 ...
 
 Number of locked synchronizers = 1
 - java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync@3f88774b
 
 , thread2 Id=529 WAITING on
 java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync@3f88774bowned
 by thread1 Id=534
 at sun.misc.Unsafe.park(Native Method)
 -  waiting on
 java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync@3f88774b
 at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
 at
 java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
 at
 java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(ReentrantReadWriteLock.java:945)
 at
 org.apache.tomcat.jdbc.pool.PooledConnection.lock(PooledConnection.java:609)
 at
 org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:752)
 ...
 
 Number of locked synchronizers = 1
 - java.util.concurrent.locks.ReentrantReadWriteLock$FairSync@184ffd83
 
 
 Having a look at the source code for both
 http://svn.apache.org/repos/asf/tomcat/tc7.0.x/tags/TOMCAT_7_0_34/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/PooledConnection.javaof
 these 
 http://grepcode.com/file/repo1.maven.org/maven2/org.glassfish.ejb/ejb-container/3.1.1/com/sun/ejb/containers/CMCSingletonContainer.java?av=f
 I
 see different lock instances but still the dump indicates that they are the
 same. Any idea on how can the java.util.lock instances be the same?
 
 Thanks,
 Amit.


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