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

[Scott Marlow]

On 06/02/2011 11:27 AM, Mircea Markus wrote:
>
> 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.

We are planning on switching over to use the TSR level syncs in AS 7.0. 
  The first part of this change will be in our connection pool management.

Thanks for all the responses about this subject!

Scott