[infinispan-dev] Non-blocking state transfer (ISPN-1424)

[Paolo Romano]

On 3/23/12 10:45 AM, Bela Ban wrote:
>> The biggest problem I remember total order having is TM transactions
>> that have other participants (as opposed to cache-only transactions).
>> I haven't followed the TO discussion on the mailing list very closely,
>> does that work now?
>
> No, I don't think that's addressed by TOM, good point in favor of having
> 2 (or more) approaches to partial replication and state transfer !
>
>
Actually, we already have code for dealing with scenarios in which ISPN 
is involved in a distributed transaction with other participants.( Pedro 
can point it out, it should be already on github.)

In this case, the solution implies necessarily the usage of 2PC, but we 
can disseminate the prepare messages within ISPN using TOM.

Pro:
- deadlock freedom at the ISPN level, which can contribute to make of 
ISPN a well-behaved (i.e. responsive) participant in a distributed 
transaction even in high contention scenarios.

Con:
- in this case we cannot determine right away the outcome of a 
transaction once it is TOM-delivered, as we need to take into account 
also the votes of external participants. Hence the need for an extra phase.