The BigIntegerTimerIdGenerator may generate a already existing Timer ID after a server crash.

The problem is that the Timer database may contain some Timers at server startup after a server crash (see JBAS-1091). The BigIntegerTimerIdGenerator does not know of these already existing timers. The first ID after a restart is always zero. Therefore, the BigIntegerTimerIdGenerator will create an already existing Timer ID as soon as the ID of a restored and not yet executed Timer is reached. This will lead to the following exception:

23:22:19,812 ERROR [TimerServiceImpl] Cannot create txtimer
java.lang.IllegalStateException: Unable to persist timer
at org.jboss.ejb.txtimer.DatabasePersistencePolicy.insertTimer(DatabasePersistencePolicy.java:126)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
at $Proxy22.insertTimer(Unknown Source)
at org.jboss.ejb.txtimer.TimerServiceImpl.createTimer(TimerServiceImpl.java:256)
at org.jboss.ejb.txtimer.TimerServiceImpl.createTimer(TimerServiceImpl.java:171)
at ch.dvbern.bpm.test.ejb.service.scheduler.JbpmSchedulerBean.timeoutHandler(JbpmSchedulerBean.java:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112)
at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166)
at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79)
at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:197)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:78)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:47)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
at org.jboss.ejb3.stateless.StatelessContainer.callTimeout(StatelessContainer.java:124)
at org.jboss.ejb.txtimer.TimerImpl$TimerTaskImpl.run(TimerImpl.java:524)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
Caused by: java.sql.SQLException: Unique constraint violation: in statement [insert into TIMERS (TIMERID,TARGETID,INITIALDATE,TIMERINTERVAL,INSTANCEPK,INFO) values
(?,?,?,?,?,?)]
at org.hsqldb.jdbc.Util.throwError(Unknown Source)
at org.hsqldb.jdbc.jdbcPreparedStatement.executeUpdate(Unknown Source)
at org.jboss.resource.adapter.jdbc.CachedPreparedStatement.executeUpdate(CachedPreparedStatement.java:95)
at org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeUpdate(WrappedPreparedStatement.java:251)
at org.jboss.ejb.txtimer.GeneralPurposeDatabasePersistencePlugin.insertTimer(GeneralPurposeDatabasePersistencePlugin.java:186)
at org.jboss.ejb.txtimer.DatabasePersistencePolicy.insertTimer(DatabasePersistencePolicy.java:122)
... 43 more

IMHO, the BigIntegerTimerIdGenerator should be replaced by a GUID algorithm or read the maximum Timer ID from the Database at startup.