[jbosscache-dev] Re: JGroups Shared Transport support in JBC

[Brian Stansberry]

Sure, no problem.

When are you expecting 1.4.1.beta2 out?

Tim Fox wrote:
> Yeah this is probably a trivial change on our side, but we just haven't 
> got round to looking at it yet. :(
> 
> If it's high priority I'll take a look soon, tomorrow ok?
> 
> Cheers
> 
> Brian Stansberry wrote:
>> Sorry Tim, I'd meant to include you on this thread from the start. :(
>>
>> We were having a discussion of how to handle the difference between a 
>> JGroups JChannel w/ a shared transport (new in 2.6.2) and the old 
>> multiplexer MuxChannel.
>>
>> If you call ChannelFactory.createMultiplexerChannel() the return type 
>> is Channel, but the code actually returns the MuxChannel 
>> implementation class. Which is reasonable; the name of the method 
>> implies the multiplexer will be used.
>>
>> But, a shared transport JChannel is actually a much better solution to 
>> JGroups resource sharing. So, question is how to get a shared 
>> transport JChannel into users' hands.
>>
>> 1) Have them specifically ask for a JChannel by calling 
>> ChannelFactory.createChannel(String) instead of 
>> ChannelFactory.createMultiplexerChannel().  Puts the issue back in the 
>> user service; e.g. JBC might add a config property to help it 
>> determine if a call to createMultiplexerChannel() or createChannel() 
>> is the desired way to go. Or maybe just switch to createChannel().
>>
>> 2) Have the createMultiplexerChannel() method internally decide 
>> whether to return a MuxChannel or a shared transport JChannel.
>>
>> Due to the late date this came up, my plan for AS 5 was #2. 
>> JBMESSAGING-1244 is a problem with that plan, but I see you have a JBM 
>> 1.4.1.BETA2 Fix Version on that, so I think it's OK.
>>
>> #1 isn't workable yet; it requires a minor change in JGroups that 
>> won't be out until 2.6.3.  After I found JBMESSAGING-1244, I pinged 
>> Bela/Manik to see if it could be done quickly in case JBMESSAGING-1244 
>> was something that wouldn't get done in time for AS 5. Sounds like 
>> it's not an issue.
>>
>> Tim Fox wrote:
>>>
>>>
>>> Manik Surtani wrote:
>>>> Is Tim even on this list?
>>>
>>> On jbosscache-dev - no I'm not
>>>
>>> Can someone recap?
>>>
>>>>
>>>> On 4 Mar 2008, at 11:58, Bela Ban wrote:
>>>>
>>>>> Releasing 2.6.3 is not really feasible, as I've just released 
>>>>> 2.6.2. So, if the change in JBC and JBM is minor (which I think it 
>>>>> is), then I'd appreciate your guys fixing this.
>>>>> Cheers,
>>>>>
>>>>> Manik Surtani wrote:
>>>>>> And I could implement this in JBC 2.1.0.GA easily enough, but if 
>>>>>> there is a viable workaround I'd rather leave this for 2.2.0 given 
>>>>>> current timeframes.
>>>>>>
>>>>>>
>>>>>> On 4 Mar 2008, at 07:14, Bela Ban wrote:
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Brian Stansberry wrote:
>>>>>>>> Being able to handle this in JBC 2.1.0 is a bit more of an issue 
>>>>>>>> due to a bug in the way JBM handles a Channel.connect() call 
>>>>>>>> (http://jira.jboss.com/jira/browse/JBMESSAGING-1244).  The bug 
>>>>>>>> basically means JBM will fail if it calls 
>>>>>>>> ChannelFactory.createMultiplexerChannel() and the call doesn't 
>>>>>>>> return a MuxChannel.  So, my intended approach for AS 5 
>>>>>>>> (override createMultiplexerChannel()and return a regular 
>>>>>>>> JChannel if it's configured for shared transport) breaks JBM.
>>>>>>>>
>>>>>>>> Maybe they'll get JBMESSAGING-1244 fixed in time for AS 5; maybe 
>>>>>>>> not.
>>>>>>>
>>>>>>> I certainly hope so, sounds like a small change (use a JChannel 
>>>>>>> type rather than a MuxChannel (extends JChannel))...
>>>>>>>
>>>>>>>> If we can get a JGroups 2.6.3
>>>>>>>
>>>>>>> Another release, so soon after 2.6.2 ? Only if absolutely 
>>>>>>> necessary. Seems to me that Tim can fix his stuff much more 
>>>>>>> quickly... In any case, let me know, I need a few days to get a 
>>>>>>> 2.6.3 out (including fixing the NPE you opened).
>>>>>>>
>>>>>>>> and JBC 2.1.0.GA able to call ChannelFactory.createChannel(), 
>>>>>>>> then I can just let JBM get a MuxChannel.
>>>>>>>
>>>>>>> This is possible in 2.6.3 by which feature/bug I implemented ?
>>>>>>>
>>>>>>> -- 
>>>>>>> Bela Ban
>>>>>>> Lead JGroups / Clustering Team
>>>>>>> JBoss - a division of Red Hat
>>>>>>
>>>>>> -- 
>>>>>> Manik Surtani
>>>>>> Lead, JBoss Cache
>>>>>> manik at jboss.org
>>>>>> msurtani at redhat.com
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> -- 
>>>>> Bela Ban
>>>>> Lead JGroups / Clustering Team
>>>>> JBoss - a division of Red Hat
>>>>>
>>>>
>>>> -- 
>>>> Manik Surtani
>>>> Lead, JBoss Cache
>>>> manik at jboss.org
>>>> msurtani at redhat.com
>>>>
>>>>
>>>>
>>>
>>
> 

-- 
Brian Stansberry
Lead, AS Clustering
JBoss, a division of Red Hat
brian.stansberry at redhat.com