As far as I know, aside from #1, Weblogic 5.1 fulfills your entire wishlist!
Our website uses weblogic for two-layer clustering: clustered app server
and clustered web servers. (shameless plug: check out www.kiko.com!!!)
Performance degradation for serialized requests is almost negligable (less
than 2%), while performance improvement for parallel requests is
trememendous.
Like I said in my original post, failover works almost everywhere except the
initial stateless-session-bean home reference on the client servlet; By
wrapping this home reference in my customized reconnecting wrapper, we
decoupled the dependency of our web tier to our app tier (i.e. now we can
simultaneously shut down all app servers and restart them and not have to
recycle our web servers).
Gene
-----Original Message-----
From: A mailing list for Enterprise JavaBeans development
[mailto:[EMAIL PROTECTED]]On Behalf Of Edward Barrett
Sent: Friday, July 14, 2000 4:43 AM
To: [EMAIL PROTECTED]
Subject: Re: Resiliency: method level failover, who provides this
I wonder if someone could confirm what can be failed over in what products
(although I perceive that WLS seems to have some of the best facilities at
present):
1) re-binding to Home (this should be easy and therefore I presume is
available)
2) idempotent stateless session bean methods (again, from the below emails I
presume this is here today)
3) what about stateful session beans (i.e. memory replication or continual
syncing with a persistent representation) ?
4) entity beans - presuming that all instances are looking at the same
database, does any server offer this facility ?
We are going to use WLS but the reason I haven't posted to the WLS
newsgroups is I would like to hear views from WLS and other server users as
to what is possible today.
Is anyone using application server clustering on a real system ?
Does it cause a performance degradation ?
Regards
Ed
-----Original Message-----
From: A mailing list for Enterprise JavaBeans development
[mailto:[EMAIL PROTECTED]]On Behalf Of Gene Chuang
Sent: Thursday, July 13, 2000 10:32 PM
To: [EMAIL PROTECTED]
Subject: Re: Resiliency: method level failover, who provides this
Not really... my stateless session beans' methods are NOT idempotent...
hence I cannot use weblogic's method failover support.
Gene
-----Original Message-----
From: A mailing list for Enterprise JavaBeans development
[mailto:[EMAIL PROTECTED]]On Behalf Of J. Matthew Pryor
Sent: Thursday, July 13, 2000 12:36 PM
To: [EMAIL PROTECTED]
Subject: Re: Resiliency: method level failover, who provides this
Doesn't Eric's post about idempotent methods contradict Gene's post about
having to wrapper re-binding to Homes etc
i.e.
> I don't know about WLE, but WLS has some EJB deployment options
> to indicate to
> the stub that it may automatically retry when a failure occurs:
>
> <home-is-clusterable>true</home-is-clusterable>
> <stateless-bean-is-clusterable>true</stateless-bean-is-clusterable>
> <stateless-bean-methods-are-idempotent>true</stateless-bean-method
> s-are-idempote
> nt>
>
[snip]
>
> Hope this helps.
>
> -Eric
Seems to contradict this
> Good call! WL 5.1 doesn't support this, and I had to hand-code a
> EJBHomeFactory that produced FailSafeHomes that wrapped EJBHome
> and provide
> transparent re-lookup in case of connection failure. This is
> definitely not
> a difficult concept and can easily be provided by the vendor, i.e.
> weblogic.ejbc generating FailSafeBeanImpl stubs...
>
> Maybe in WL 6.0???
>
> Gene
Just hoping to clarify either my foggy mind to 2 difering opinions
Thanks,
Matthew
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
