Compatibility Requirements (Was Re: [jboss-dev] AS 5.1 and JBoss Messaging 2)

[Jason T. Greene]

Adrian Brock wrote:
> On Tue, 2009-02-17 at 14:00 -0600, Jason T. Greene wrote:
>> Tim Fox wrote:
>>> Jason T. Greene wrote:
>>>> I really wish we could. Tim said theres pretty much no was JBM2 can 
>>>> make Beta1, but it could make CR1. The question is, would it be 
>>>> stable and TCK compliant enough that it doesn't end up delaying GA?
>>> No, JBM 2.0 is a major release and is not compatible with JBM 1.4. 
>>> That's why we can't replace JBM 1.4 in a minor release since AS minor 
>>> versions need to be compatible, and why it's being offered as a 
>>> technology preview, not replacement for default JMS provider.
>> Where did this rule come, and what level of compatibility are we talking 
>> about? We do need EE API compatibility, and ideally all of our public 
>> APIs should be BC (so that developers don't have to rewrite their apps), 
>> but IMO we don't need wire protocol compatibility. You already can't 
>> cluster 5.1 and 5.0 together.
>>
>> The insane levels of compatibility should be reserved for EAP, but 5.1 
>> is the source of an EAP major version, so it doesn't need it.
>>
> 
> No. JMS is a client/server protocol not a server/server protocol.

Sure, but it's just an API with no required level of interoperability or 
standard wire protocol. Any compatibility we offer is a feature not a 
requirement of any kind.

> 
> If clients (and that includes legacy servers) using JBM 1.x
> can't talk to jms servers using JBM 2.x
> then the packages names need to be changed so that those clients
> can also deploy the JBM 2.x client code alongside their own version.

I agree. In fact, it needs to be done anyway regardless of what version 
AS includes.

> Although this is not an EAP list, that requirement is more likely to
> come up with EAP since we never shipped JBM by default in the
> 4.x community releases, while we did with EAP 4.3
> 

I will raise that on the EAP list, we need to be sure we understand 
their requirements.

-- 
Jason T. Greene
JBoss, a division of Red Hat