Good idea Richard. But as you say it assumes that the vendor implementation
is doing stateless bean instance pooling. Also your ability to control the
number
of pooled instances and so on may be limited. Being a control freak, I would
probably
go the other way.
-Chris.
> -----Original Message-----
> From: Richard Monson-Haefel [SMTP:[EMAIL PROTECTED]]
> Sent: Monday, March 22, 1999 12:45 PM
> To: [EMAIL PROTECTED]
> Subject: Re: EJB Activation/Passivation.
>
> I like Chris' idea.
>
> However, to avoid the complexities of pooling, try wrapping your MQ Series
> API with a stateless session bean. You can than obtain the resource
> connection in the MQSeriesBean in its setSessionContext method and
> disconnect it in the ejbRemove( ) method of the statless session bean.
> Than
> use this stateless session bean from your stateful session bean.
>
> This will work providing your EJB server uses instance pooling and
> implements these methods according to the specification. Using this
> design,
> your stateless session beans can themselves become your MQ series pool.
>
> Richard Monson-Haefel
> Author, Enterprise JavaBeans (O'Reilly)
>
>
> -----Original Message-----
> From: Chris Raber
> To: [EMAIL PROTECTED]
> Sent: 3/22/99 10:13 AM
> Subject: Re: EJB Activation/Passivation.
>
> Well, it's probably cheating in terms of the spec (and possibly not
> portable
> as a result), but you could create a separate "connection pool" service
> for
> these MQ series connections, and have your session bean allocate and
> de-allocate instances from the pool per session bean invocation. This
> way no
> state needs to be passivated/activated.
>
> We have customers that have done this sort of thing for CICS connections
> with good success.
>
> -Chris.
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]]
> > Sent: Monday, March 22, 1999 10:29 AM
> > To: [EMAIL PROTECTED]
> > Subject: EJB Activation/Passivation.
> >
> > I am writing an EJB that uses MQSeries.
> >
> > The bean is a stateful session bean.
> >
> > Since MQ series is an external resource and the classes are not
> > serializable
> > during passivation I close the connections and set the objects to
> null.
> > Then, when the bean is activated, I reconnect to MQ Series.
> >
> > These beans are used over a long period of time during which
> > activation/passivation occurs many times.
> >
> > I would like to be able to create the connection once. Use the
> connection
> > for an extended period of time. Then close the connection.
> >
> > In regards to the stateful session bean the EJB spec. says:
> >
> > "In advanced cases, a session Bean's conversational state may contain
> open
> > resources. Examples of this are: open files, open sockets, and open
> > database
> > cursors. It is not possible for a container to retain open resources
> while
> > a
> > session Bean is passivated. A developer of such a session Bean must
> close
> > and open the resources using the ejbPassivate and ejbActivate
> > notifications."
> >
> > However in regards to the entity bean the spec. says:
> >
> > "The ejbPassivate() method gives the enterprise Bean the chance to
> release
> > any resources that should not be held while the instance is in the
> pool
> > (these resources typically had been allocated during the ejbActivate()
> > method)."
> >
> >
> > Is there any way that I can avoid reconnecting each time the bean is
> > passivated/activated?
> >
> > Do the same rules regarding open resources for session beans apply to
> > entity
> > beans?
> >
> >
> > Thanks,
> >
> > Phillip Schroder
> > Senior Software Engineer
> > Carreker-Antinori, Inc
> >
> > [EMAIL PROTECTED]
> >
> >
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