[jbosscache-dev] JGroups concurrent stack and parallelizing messages from the same sender

[Manik Surtani]

On 13 May 2008, at 14:22, Bela Ban wrote:

>
>
> Manik Surtani wrote:
>>
>>> You can use the above mechanism. However, you have to make sure  
>>> that any thread
>>>
>>>  * uses synchronous replication
>>>  * the commits are synchronous as well
>>>
>>> This won't work for asynchronous replication, but I don't think it  
>>> is needed here anyway right ?
>>
>> It is most critical in sync replication, correct, but why should it  
>> not work with the async case as well?  I'm guessing misaligned  
>> packets?
>
> Commit(A::TX-1) could be received *after* Commit(A::TX-2). Admitted,  
> a rare case, but if the COMMIT(A:TX-1) is lost and needs to be  
> retransmitted, this could happen

The TxInterceptor would just throw out Commit(A::TX-2) if it hasn't  
received a prepare for that TX yet.  Locks would still be held by TX1  
assuming it's prepare has already been received.

I guess the problem is in 1-PC but that is to be expected anyway.

--
Manik Surtani
Lead, JBoss Cache
manik at jboss.org