> That said, our loadtests indicate that WAS on Linux is much more reliable=
 than
> JBoss with Sun JDK 1.4.x on Linux. So for production WAS might not be suc=
h a
> bad idea after all.
>=20

I'd like to see that (of course you can't publish them by license of
WebSphere in fact probably this statement violates the license).  I'll bet
you deployed in option B (default) with no eager loading and pessimistic
transactions (again defaults...safe...but very slow).  Furthermore, I'll be=
t
your value objects are created in your session bean rather than in the
ejbLoad.  Lastly, Was that WAS on IBM JDK and JBoss on Sun JDK?  Sun's JDK
is probably the slowest and has a nasty classloading bug that you're very
likely to hit on JBoss 3.2.2 and below under load and might hit on 3.2.3.
(It is never fair to compare on two different VMs.)

>> In at least this one regard (auto deployment), I do consider JBoss
>> superior to Websphere. Deploying apps is (usually) very easy.  However,
>> JBoss annoys the mess out of me with their weird class-loader scheme.
>> The first time I realized classes were being shared across applications,
>> when I didn't expect them to, I almost passed out.
>=20
> You have to pay attention to classloaders in WAS, too. They are highly
> configurable!
>=20

The issue with classloaders is this.  How would you like all communication
between all components in the /deploy directory to be 10 times slower (pass
by value semantics)?  The bottom line is that to pass by reference you must
share class definitions.  PassByValue is slow.

You do know you can turn that off or scope it.  You can decide just which
packages share what and even do it in pyramids.

The real kicker is that while we need to share class definitions for
performance, we also need to split up our packaging for uptime and
maintenance (meaning I don't want to bring the whole system down just to
redeploy one ejb).  However that has some nasty classloader implications as
well.  You can get it right once you understand how it all works.  Its
really not that difficult or troublesome once you understand how it works.

Maybe at some point I could give a talk on how to package and set up your
classloader repositories....and walk through the classloader code.  That=B9s
probably 2 hours worth.  Is August open?

-Andy

> Feel free to drop me a private email and let me know how things went...
>=20
> -hendrik_______________________________________________
> Juglist mailing list
> [EMAIL PROTECTED]
> http://trijug.org/mailman/listinfo/juglist_trijug.org
>=20


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