Fan:

Why are you singling out JDBC operations to avoid?  What is it about them
that is especially "blocking"?

Thank you for your time!

+++++++++++++++++++++
Jeff Maass <[email protected]>
linkedin.com/in/jeffmaass
stackoverflow.com/users/373418/maassql
+++++++++++++++++++++


On Thu, May 14, 2015 at 9:41 AM, Fan Jiang <[email protected]> wrote:

> 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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