Re: [infinispan-dev] discussion about impact of using TransactionSynchronizationRegistry in AS7...

On 2 Jun 2011, at 15:09, Scott Marlow wrote: > On 06/02/2011 09:50 AM, Mircea Markus wrote: >> >> On 2 Jun 2011, at 13:19, Scott Marlow wrote: >> >>> On 06/02/2011 05:31 AM, Mircea Markus wrote: >>>> >>>> On 1 Jun 2011, at 20:49, Scott Marlow wrote: >>>> >>>>> I posted a message on the as7-dev ml >>>>> (http://lists.jboss.org/pipermail/jboss-as7-dev/2011-May/002254.html), >>>>> about switching to use the TransactionSynchronizationRegistry. >>>>> >>>>> Does Infinispan currently register Transaction synchronization objects? >>>> yes >>>>> Does Infinispan currently register synchronizations via >>>>> TransactionSynchronizationRegistry (TSR)? >>>> no, we register synchronizations through transaction.registerSynchronization >>>>> >>>>> I'm trying to get a sense for, what would happen if container managed >>>>> (AS7) session beans were registered with the active JTA transaction via >>>>> the TSR. >>>>> >>>>> If AS7 switches to use the TSR, I think that Infinispan might need to >>>>> ensure that it doesn't attempt to register with the TX too late. >>>> right. One way to go is by making the registration code pluggable. >>> >>> I should point out that I believe its only a problem, to call Transaction.registerSynchronization() after the point, where the ordering cannot be correct. However, no such checking is performed if no components are registering their syncs via TransactionSynchronizationRegistry. >>> >>> So, another question, how likely would it be, that an application would see Infinispan registering a sync via Transaction.registerSynchronization(), after the transaction commit has been initiated? >> ATM Infinispan allows the registration if the transaction is in one of the following states: Status.STATUS_ACTIVE || Status.STATUS_PREPARING. If tx is in any other state the sync won't be registered and a exception is instead sent to the user. >>> >>> If Transaction.registerSynchronization() will always be called by Infinispan before the transaction commits. We shouldn't have to be as concerned about support for registering the Infinispan syncs with TransactionSynchronizationRegistry. >> >>> >>> If the answer is we aren't sure or Transaction.registerSynchronization() could happen after the transaction commit has been started, we should have it be pluggable. >> >> From Jonathan's comment[1] I understand that "interposed Synchronizations must be called after non-interposed ones". That seems to be true disregarding tx's status. Or am I wrong? > > Jonathan also commented here a few minutes ago, with further clarification of the exact rules. Best to read what he said directly (he described the situation in much better detail than me). http://lists.jboss.org/pipermail/jboss-as7-dev/2011-June/002275.html > > Copying from his email: > > " > So, the rule for activity in beforeCompletion is: > > - a Sync registered via registerSynchronization may call either registerSynchronization or registerInterposedSynchronization. > > - a Sync registered via registerInterposedSynchronization may call only registerInterposedSynchronization. > " Thanks for the clarification. The Syncs we register do not do any subsequent Sync registration in beforeCompletion so should be on the safe side.