[infinispan-dev] Infinispan tx, config and multithreading

[Łukasz Moreń]

Newly created threads were not associated with any transaction, so I
suppose it was a problem. Sharing transaction between threads seems to
be a good solution.
Thanks for help!

2009/8/13, Jason T. Greene <jason.greene at redhat.com>:
> Correct. Also there could be read races as well, so if you are going to
> share a tx between threads, i would use some shared lock to gaurantee
> that only one thread can use it at a time. BTW this means you have to
> properly suspend/resume the TX via the TM API as well.
>
> Emmanuel Bernard wrote:
>> Modifying a transaction means applying muations (like SQL INSERT /
>> UPDATE / DELETE) to the transactional resource?
>>
>> On 13 août 09, at 15:07, Jason T. Greene wrote:
>>
>>> When using transactions, the context is bound to the transaction, and
>>> you can move a transaction between threads. However, you should only
>>> be modifying a transaction with one thread at a time.
>>>
>>> Emmanuel Bernard wrote:
>>>> Could it be that you are not using the same transaction between
>>>> different threads (ie you physically start different ones or
>>>> different  "Infinispan contexts")?
>>>> Infini guys, do you support transactional operation spanning several
>>>> concurrent threads?
>>>> On 13 août 09, at 14:04, Łukasz Moreń wrote:
>>>>> I've tried with JBoss AS transaction manager and JBossStandaloneTM.
>>>>> The result is this same in all cases - error during merge.
>>>>>
>>>>> 2009/8/12, Emmanuel Bernard <emmanuel at hibernate.org>:
>>>>>> Ok I understand better now.
>>>>>> Do your tests in JBoss AS with it's decent transaction manager
>>>>>> (infinispan should have a config for it)
>>>>>> For unit testing, force the indexing process in hibernate to use a
>>>>>> single thread (I ghnk it's possible ask Sanne of you don't know how).
>>>>>>
>>>>>> Exposing some configuration to infinispan makes sense. can you
>>>>>> start a
>>>>>> thread explainig what is configurable and which one you think we
>>>>>> should expose to hsearch users. Ideally I would like to offer one or
>>>>>> two defaut config scenarios and allow to fallback to a custom config.
>>>>>>
>>>>>> Emmanuel
>>>>>>
>>>>>> On 12 août 2009, at 11:58, Łukasz Moreń <lukasz.moren at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Sorry, but my wifi does not work well today. I will try to explain
>>>>>>> it more clear.
>>>>>>>
>>>>>>> I'm using DummyTransactionManager available for Infinispan.
>>>>>>> It associates transaction with the calling thread.
>>>>>>>
>>>>>>> Steps to update index:
>>>>>>>
>>>>>>> 1. index writer acquires lock - begin of transaction
>>>>>>>
>>>>>>> 2. if it is necessary, index writer delegates new threads to do
>>>>>>> merge work.
>>>>>>> Those merge threads do not see changes made so far from begin of
>>>>>>> transaction,
>>>>>>> and are looking for segments which are not yet in index.
>>>>>>> Changes will be visible when AD.3 is completed.
>>>>>>> For tests i tried to commit transaction when merge starts and then
>>>>>>> everything worked well. But then i need to start it again.
>>>>>>>
>>>>>>> 3. index writer releases lock - transaction is commited, all changes
>>>>>>> made in this transaction are visible for other threads.
>>>>>>>
>>>>>>> Maybe using some other transaction manager could help?
>>>>>>>
>>>>>>> What about Infinispan cache configuration? Some configuration
>>>>>>> mechanism should be exposed to the user,
>>>>>>> or we can hardcoded one in InfinispanDirectoryProvider is enough?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 2009/8/12 Emmanuel Bernard <emmanuel at hibernate.org>
>>>>>>> why?
>>>>>>> Emmanuel Bernard
>>>>>>> Pending
>>>>>>> you there?
>>>>>>> Emmanuel Bernard
>>>>>>> Pending
>>>>>>> Ok please describe in details what is going on. From what you are
>>>>>>> describing the tx cannot see all segments which looks like an
>>>>>>> infinispan bug to me.
>>>>>>> Pending
>>>>>>>
>>>>>>> As a back up you can try wo transaction and see if that works
>>>>>>> Emmanuel Bernard
>>>>>>> Pending
>>>>>>> technically the lucene index should cope with that
>>>>>>> Emmanuel Bernard
>>>>>>> 11:16
>>>>>>> but I like this approach less
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Let's try and chat by email IF I'm not online, I need to run on some
>>>>>>> errands today.
>>>>>>>
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>>>
>>>
>>> --
>>> Jason T. Greene
>>> JBoss, a division of Red Hat
>>
>
>
> --
> Jason T. Greene
> JBoss, a division of Red Hat
>