class incompatibilites b/w JBM 1.4 and JBM 2

[jmesnil]

I'm checking that the bridge can successfully bridge a JBM 2 destination to a JBM 1.4 destination.

I'm using JBoss AS 5.0.0.GA which hosts the bridge (JBAS 5 is bundled with JBM 1.4).
The destination source will be a remote queue hosted on a remote JBM2 server
The destination target will be a local queue

I was able to check the bridge but I had to modify a few classes to do so.

There are some classes which are in both JBM 1.4 and JBM 2 but with incompatible version (methods added/removed)
The clashing classes are all in the org.jboss.messaging.util package:
* ExecutorFactory
* JBMThreadFactory
* OrderedExecutorFactor
* XMLUtil

Since the bridge requires to run code from both JBM 1.4 and JBM 2, the class clashes appeared when I first run the code w/o any modification.

To test the bridge, I renamed with classes from XXX to XXX2 in JBM2 and the code ran w/o any problem.

To avoid these class incompatibilities, there are several solutions:
1. renamed the classes
2. moved them to another package
3. use classloader to isolate the clashing classes

I talked to Clebert about (3) but he advised against it as it'll be a PITA to maintain (and I've not found the documentation to do that in JBAS 5).

Clebert suggested to rename the package org.jboss.messaging.util to org.jboss.messaging.utilities to avoid any further clash.

I'm ok with his suggestion and if everyone agree, i'll update the trunk.
wdyt? any other suggestions?.fr/

[timfox]

"jmesnil" wrote:

Clebert suggested to rename the package org.jboss.messaging.util to org.jboss.messaging.utilities to avoid any further clash.

+1

or org.jboss.messaging.common

[timfox]

Furthermore - we should ensure there is zero overlap between any other 1.x and 2.x class names as this may cause other subtle issues when running both sets of classes in the same classloader.

[jmesnil]

i'll rename it to o.j.messaging.utilities.

as far as i checked there were no other clashes:

JMS code is in o.j.jms in 1.4 while JBM 2 code is in o.j.messaging.jms
Both version use o.j.messaging.core but JBM 1.4 code is below "impl" subpackage while JBM2 is splitted in many subpackages

I'll do a thorough check to be sure that there is no other class clashes than the util package

[clebert.suconic]

"timfox" wrote:
Furthermore - we should ensure there is zero overlap between any other 1.x and 2.x class names as this may cause other subtle issues when running both sets of classes in the same classloader.

Can't we rename the whole base package? (org.jboss.messaging to something else?)

I have been there when we had to play with SAR isolations and it wasn't any fun. I foresee users using both JBM 1.4 and JBM 2.0 on the same VM during migrations... and it would be better to be completely isolated.

We could verify of course if there are no clashes.. but if renaming the package is acceptable.. that would give us some peace of mind.

[timfox]

Can't we rename the whole base package? (org.jboss.messaging to something else?)

Yes. I suggest org.jboss.jbm.*

But don't do it now, since it will cause a merge nightmare for anyone working on stuff. Let's add a JIRA and do at it then end.

[clebert.suconic]

https://jira.jboss.org/jira/browse/JBMESSAGING-1484