Deadlock detection broken?
The problem is client apps would freeze.
I use swing clients connecting to a servlet via http.
The servlet runs in jboss-3.2.2RC4.
This in turn, calls a session bean which calls CMP entity beans etc.
The blocking appears to occur on the database. I did a kill -3 on jboss, and this is one of the hung threads.
Looks like deadlock at the database level, if so, why didn't the deadlock detection pick it up?
I have subsequently done deadlock tests (i.e. purposely creting deadlock), and the deadlock detection picks it up everytime.
This case happened after the server had been running for a couple of weeks.
Note, my code is simple, I'm not using any synchronization primitaves or anything dodgy.
I'm using purely CMP and not coding any jdbc calls directly.
"Thread-7" daemon prio=1 tid=0x4f0606c8 nid=0x5dfa waiting on condition [4f2a9000..4f2ab714]
at com.mysql.jdbc.Field.(Field.java:100)
at com.mysql.jdbc.MysqlIO.unpackField(MysqlIO.java:1190)
at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:252)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:985)
at com.mysql.jdbc.MysqlIO.sqlQuery(MysqlIO.java:917)
at com.mysql.jdbc.Connection.execSQL(Connection.java:1841)
- locked <0x46e81288> (a java.lang.Object)
at com.mysql.jdbc.Connection.execSQL(Connection.java:1775)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1220)
- locked <0x46e81288> (a java.lang.Object)
- locked <0x46e8d608> (a com.mysql.jdbc.Statement)
at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:2288)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1548)
at com.mysql.jdbc.Connection.(Connection.java:486)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:326)
at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.createManagedConnection(LocalManagedConnectionFactory.java:143)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.createConnectionEventListener(InternalManagedConnectionPool.java:372)
at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:185)
at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:459)
at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:417)
at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:317)
at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:469)
at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:800)
at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:102)
at org.jboss.ejb.plugins.cmp.jdbc.JDBCAbstractQueryCommand.execute(JDBCAbstractQueryCommand.java:135)
at org.jboss.ejb.plugins.cmp.jdbc.JDBCAbstractQueryCommand.execute(JDBCAbstractQueryCommand.java:93)
at org.jboss.ejb.plugins.cmp.jdbc.JDBCFindEntityCommand.execute(JDBCFindEntityCommand.java:49)
at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.findEntity(JDBCStoreManager.java:593)
at org.jboss.ejb.plugins.CMPPersistenceManager.findEntity(CMPPersistenceManager.java:299)
at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.findEntity(CachedConnectionInterceptor.java:300)
at org.jboss.ejb.EntityContainer.findLocal(EntityContainer.java:636)
at sun.reflect.GeneratedMethodAccessor40.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.ejb.EntityContainer$ContainerInterceptor.invokeHome(EntityContainer.java:1042)
at org.jboss.ejb.plugins.AbstractInterceptor.invokeHome(AbstractInterceptor.java:88)
at org.jboss.ejb.plugins.EntitySynchronizationInterceptor.invokeHome(EntitySynchronizationInterceptor.java:185)
at org.jboss.resource.connectionmanager.CachedConnectionInterceptor.invokeHome(CachedConnectionInterceptor.java:214)
at org.jboss.ejb.plugins.AbstractInterceptor.invokeHome(AbstractInterceptor.java:88)
at org.jboss.ejb.plugins.EntityInstanceInterceptor.invokeHome(EntityInstanceInterceptor.java:91)
at org.jboss.ejb.plugins.EntityLockInterceptor.invokeHome(EntityLockInterceptor.java:61)
at org.jboss.ejb.plugins.EntityCreationInterceptor.invokeHome(EntityCreationInterceptor.java:28)
at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInterceptor.java:88)
at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.java:349)
at org.jboss.ejb.plugins.TxInterceptorCMT.invokeHome(TxInterceptorCMT.java:98)
at org.jboss.ejb.plugins.SecurityInterceptor.invokeHome(SecurityInterceptor.java:92)
at org.jboss.ejb.plugins.LogInterceptor.invokeHome(LogInterceptor.java:120)
at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invokeHome(ProxyFactoryFinderInterceptor.java:93)
at org.jboss.ejb.EntityContainer.internalInvokeHome(EntityContainer.java:484)
at org.jboss.ejb.Container.invoke(Container.java:720)
at org.jboss.ejb.plugins.local.BaseLocalProxyFactory.invokeHome(BaseLocalProxyFactory.java:293)
at org.jboss.ejb.plugins.local.LocalHomeProxy.invoke(LocalHomeProxy.java:110)
at $Proxy48.findByPrimaryKey(Unknown Source)