why?when many times to insert to db?
jboss error log;
14:59:43,828 WARN [TransactionImpl] Transaction TransactionImpl:XidImpl [Format
Id=257, GlobalId=caolianjian//4415, BranchQual=] timed out. status=STATUS_ACTIVE

14:59:53,359 WARN [TransactionImpl] Transaction TransactionImpl:XidImpl [Format
Id=257, GlobalId=caolianjian//4599, BranchQual=] timed out. status=STATUS_ACTIVE

14:59:53,375 ERROR [BeanLock] Saw rolled back tx=TransactionImpl:XidImpl [Format
Id=257, GlobalId=caolianjian//4599, BranchQual=]
14:59:53,375 ERROR [LogInterceptor] TransactionRolledbackException, causedBy:
java.lang.RuntimeException: Transaction marked for rollback, possibly a timeout
at org.jboss.ejb.plugins.lock.QueuedPessimisticEJBLock.doSchedule(Queued
PessimisticEJBLock.java:201)
at org.jboss.ejb.plugins.lock.QueuedPessimisticEJBLock.schedule(QueuedPe
ssimisticEJBLock.java:157)
at org.jboss.ejb.plugins.EntityLockInterceptor.invoke(EntityLockIntercep
tor.java:85)
at org.jboss.ejb.plugins.EntityCreationInterceptor.invoke(EntityCreation
Interceptor.java:53)
at org.jboss.ejb.plugins.AbstractTxInterceptor.invokeNext(AbstractTxInte
rceptor.java:84)
at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxIntercep
torCMT.java:243)
at org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:1
04)
at org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityInterceptor.
java:117)
at org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:191)
at org.jboss.ejb.plugins.ProxyFactoryFinderInterceptor.invoke(ProxyFacto
ryFinderInterceptor.java:122)
at org.jboss.ejb.EntityContainer.internalInvoke(EntityContainer.java:483
)
at org.jboss.ejb.Container.invoke(Container.java:674)
at sun.reflect.GeneratedMethodAccessor48.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBea
nDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:549)
at org.jboss.invocation.jrmp.server.JRMPInvoker.invoke(JRMPInvoker.java:
359)
at sun.reflect.GeneratedMethodAccessor47.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:261)
at sun.rmi.transport.Transport$1.run(Transport.java:148)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:144)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:4
60)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport
.java:701)
at java.lang.Thread.run(Thread.java:534)