One thing to note is that you should try to avoid JDBC operations in a
bolt, as they may block the bolt and affect the topology's performance. Try
to do the database access asynchronously, or create a separate thread for
JDBC operations.

2015-05-14 10:30 GMT-04:00 Mason Yu <[email protected]>:

> Interesting.....  Hibernate hooks inside a J2ee container or Spring
> which requires a specific OR mapping to a 20th century RDBMS.
> Storm works in a Linux distributed environment which does not
> need a RDBMS.  RDBMS's do not work in a distributed environment.
>
> Mason Yu Jr.
> CEO
> Big Data Architects, LLC.
>
> 著名的孫子
>
> On Thu, May 14, 2015 at 9:58 AM, Stephen Powis <[email protected]>
> wrote:
>
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>>
>> Hello everyone!
>>
>> I'm currently toying around with a prototype built ontop of Storm and
>> have been running into some not so easy going while trying to work with
>> Hibernate and storm.  I was hoping to get input on if this is just a case
>> of "I'm doing it wrong" or maybe get some useful tips.
>>
>> In my prototype, I have a need to fan out a single tuple to several bolts
>> which do data retrieval from our database in parallel, which then get
>> merged back into a single stream.  These data retrieval bolts all find
>> various hibernate entities and pass them along to the merge bolt.  We've
>> written a kryo serializer that converts from the hibernate entities into
>> POJOs, which get sent to the merge bolt in tuples.  Once all the tuples get
>> to the merge bolt, it collects them all into a single tuple and passes it
>> downstream to a bolt which does processing using the entities.
>>
>> So it looks something like this.
>>
>>                       ---- (retrieve bolt a) ----
>>                     / ---- (retrieve bolt b) ----\
>>                    /------(retrieve bolt c) -----\
>> --- (split bolt)------(retrieve bolt d)-------(merge bolt) -----
>> (processing bolt)
>>
>> So dealing with detaching the hibernate entities from the session to
>> serialize them, and then further downstream when we want to work with the
>> entities again, we have to reattach them to a new session....this seems
>> kind of awkward.
>>
>> Does doing the above make sense?  Has anyone attempted to do the above?
>> Any tips or things we should watch out for?  Basically looking for any kind
>> of input for this use case.
>>
>> Thanks!
>>
>>
>


-- 
Sincerely,
Fan Jiang

IT Developer at RENCI
[email protected]

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