Porting Applications from WebSphere to WebLogic?

JFP queries: "I work for a division of a manufacturing company. We're currently running IBM WebSphere 3.5. We are considering a switch to BEA WebLogic 6./7. Has anyone had luck with IBM's upgrade path? Has anyone else ported a WebSphere 3.5 application to WebLogic? If so, how much of code did you have to rewrite? Are there any 'gotcha!'s that you ran into that you would care to pass along?"

Re:Advice On Moving From JBoss to WebLogic

[Gaijin42]

JBoss will be a relitively easy upgrade, since JBoss does not include any vendor extentions to Java. Therefore your app should be "vanilla" The websphere to weblogic upgrade could be more difficult, because there are vendor extentions. Any code which used that vendor extention will most likely need to be re-written.

Java is write once run anywhere, but only if you stick to the standard. The standard doesn't do everything (yet) so the vendors have pushed the envelope (Just like the browser war)

If you write to the standard you are fine. If you need/want the advanced features, be prepared for migration re-writes.

upgrade problems

[alayne]

The biggest problem with upgrading from WebSphere 3.5 to anything is that it is pre J2EE 1.2 so it isn't very compliant. The deployment descriptors are not proprietary and the configuration is locked away in the Websphere Admin Database.

Upgrading from 3.5 to 4.0 is not a great process, The server config comes across okay and most of your DDs will come over, but you are required to make sure all your code is supported on the new platform. if you've got old JSPs (.91 or lower) or use EJB 1.0 you will need to hand edit them, the upgrade will fail. Also, if you are using deprecated IBM APIs you need to figure out which ones those are and stop using them. In the end when all is said and done, you are now stuck on websphere 4.0. Its fairly stable, but a beast to administer.

Upgrading to BEA is pretty good. I haven't worked with 7.0 but 6.1 works like a champ. Its really standards compliant. As long as you've got to do some rework I would reccomend this option.

Also, you may wish to check out Cacheon [cacheon.com] I saw their demo at Java One and I was pretty impressed. I don't know if they handle your particular problem, but they definitely do automated J2EE Migration.