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From Todd Nine <t...@spidertracks.com>
Subject Re: Help with Cassandra JPA plugin
Date Tue, 08 Mar 2011 20:46:09 GMT
Hey Kevin,
  Thanks for the reply.  To be clear, I'm not actually creating a JDO
plugin.  Rather I'm migrating what I've done from JDO to JPA.  The
demand for JPA is much greater in the community, and we would prefer to
use it here as well.   My biggest hurdle is finding good developer
documentation to allow me to create the best plugin possible using open
JPA.  If you can give me any guidance on the issues below for a JPA only
implementation, I would really appreciate it.

Thanks,

Todd


On Tue, 2011-03-08 at 13:58 -0600, Kevin Sutter wrote:

> Some general comments...  Extending the OpenJPA kernel for JDO is
> definitely doable.  The original code base (BEA's Kodo) had a JDO
> personality, but it was never contributed to the OpenJPA project.  At
> least for a period of time (I don't know if it still is), BEA and then
> Oracle continued to support this JDO personality internally.  So, I
> know it's a doable endeavor...
> 
> The other bit of news is that our own Craig Russell is a bit of JDO
> expert...  :-)  And, he might even know a thing or two about the JDO
> personality.
> 
> Good luck,
> Kevin
> 
> 
> On Mon, Mar 7, 2011 at 10:22 PM, Todd Nine <todd@spidertracks.com>
> wrote:
> 
>         Hi guys,
>          I've previously developed a JDO plugin for Cassandra using
>         Datanucleus.  I'm now helping the datastax guys develop the
>         JPA plugin
>         using open JPA.  I'm having some trouble I would use a hand
>         with from
>         developers.
>         
>         Current version 2.1.0
>         
>         
>         Issue 1:  Defining an identity generator at the plugin level.
>         
>         
>         Most of our users will want a TimeUUID generated as the
>         default entity
>         Id.  We do not want to do this as a string, but rather want to
>         use the
>         actual UUID object.  As you can see from my code here, I'm
>         defining the
>         generator at the entity level.  Since this will be a default
>         use case
>         for a lot of our users, I want to make it a standard part of
>         our plugin.
>         
>         https://github.com/riptano/hector-jpa/blob/master/src/test/java/com/datastax/hectorjpa/bean/TimeUuidEntity.java
>         
>         and
>         
>         https://github.com/riptano/hector-jpa/blob/master/src/main/java/com/datastax/hectorjpa/sequence/TimeUuid.java
>         
>         
>         
>         Issue 2:  Allocate is never invoked on my sequence generator,
>         I'm
>         assuming this is due to incorrect setup that will be resolved
>         in issue
>         1.
>         
>         
>         Issue 3: Do I need to synchronize the next call internally in
>         my
>         Sequence generator?  Given the high throughput of our JPA
>         clients, I
>         don't want to accidentally return the same UUID to multiple
>         callers.
>         
>         
>         Thanks,
>         
>         
>         
>         --
>         todd
>         SENIOR SOFTWARE ENGINEER
>         
>         todd nine| spidertracks ltd |  117a the square
>         po box 5203 | palmerston north 4441 | new zealand
>         P: +64 6 353 3395
>         E: todd@spidertracks.co.nz W: www.spidertracks.com
>         
>         
>         
>         
>         
>         
> 
> 

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