LockTimedOutException when trying to call an EJB multiple times

[Ragavan]

Hi all..
I am trying to call an EJB(a Stateful EJB which connects to
an IMAP Server) from a Servlet through a link in the browser. Clicking
on the link calls the Servlet which inturn calls the EJB. Everything
is fine when I single click on the link. But when I click on the
link twice continously(or when i click it many times continously),
I get the following LockTimedOutException.

Can anyone help me with this problem

Tue Mar 06 10:39:39 GMT 2001:<I> <EJB JAR deployment Z:/mail/mail/misc/JBuilder/MailApp/MailEJB.jar>
Transaction: '983874862705_9' rolled back due to EJB exception:
weblogic.ejb.extensions.LockTimedOutException: Lock for primaryKey:983874917434_1
could not be acquired without waiting.
at weblogic.ejb.internal.LockManagerImpl.lock(LockManagerImpl.java:134)
at weblogic.ejb.internal.LockManagerImpl.lock(LockManagerImpl.java:81)
at weblogic.ejb.internal.StatefulEJBCache.bind(StatefulEJBCache.java:448)
at weblogic.ejb.internal.StatefulEJBObject.getContextForInvoke(StatefulEJBObject.java:159)
at weblogic.ejb.internal.BaseEJBObject.preInvoke(BaseEJBObject.java:445)
at com.vizzavi.mail.model.common.MailBeanEOImpl.getMessageHeaders(MailBeanEOImpl.java:106)

many a thanks
Ragavan

[Rob Woollen]

Search through this newsgroup or consult the EJB spec. You will find a
lot of info on this topic.

A stateful session bean does not support concurrent calls. The EJB 1.1
spec requires that we throw a RemoteException to a concurrent caller.

WLS 6 includes an option <allow-concurrent-calls> which in accordance
with the EJB 2.0 specification allows us concurrent callers to wait.

-- Rob

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[Ragavan]

Thanks Rob for your answer. I got the required information.