[infinispan-dev] Infinispan tx, config and multithreading

[Sanne Grinovero]

Hi Łukasz,
what is your usage of these threads? did you consider using one
transaction per thread?

Sanne

2009/8/13 Łukasz Moreń <lukasz.moren at gmail.com>:
> 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.
>>>>>>>>
>>>>> _______________________________________________
>>>>> infinispan-dev mailing list
>>>>> infinispan-dev at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>>>>
>>>>
>>>> --
>>>> Jason T. Greene
>>>> JBoss, a division of Red Hat
>>>
>>
>>
>> --
>> Jason T. Greene
>> JBoss, a division of Red Hat
>>
>
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