Classloading issues in Gora

[Lewis John Mcgibbney <le...@gmail.com>]

Hi Folks,
A while back we addressed 'GORA-72 Make Gora OSGi ready'[0].
Later on when Scott Stults completed the gora-solr module (yeehaaa) we
discovered the inevitable classloading/jar hell problem identified by
Alfonso in 'GORA-257 Use separate class loaders for each module'
Today when I was messing around with gora-solr module I 'accidentally' ran
the test suite against trunk and came across the classloading issues
associated with conflicting zookeeper versions in gora-hbase and gora-solr
TRUNK code.
It should be noted that *most-likely* this particular zookeeper problem
will vanish once we've merged GORA_94 branch back into trunk as the HBase
upgrade has been made... however this is a far from an idyllic resolution
by any means.
I therefore wanted to get some insight into what we can do about the
classloading issue ebtween modules.
I am by no means familiar with OSGi environments... therefore although my
understanding of this problem is clear... my suggestions for a solution are
virtually non-existent at the moment.
Any ideas folks?
Ta
Lewis

[0] https://issues.apache.org/jira/browse/GORA-72
[1] https://issues.apache.org/jira/browse/GORA-257

-- 
*Lewis*

Re: Classloading issues in Gora

[Henry Saputra <he...@gmail.com>]

I suppose you meant "should not make Gora rely on it".

Maybe we could add one more module with light OSGi-like feature to
support deployment of multi stores of Gora in an application.

It could be as simple as having custom class loader for Gora packages.

- Henry


On Mon, Jan 27, 2014 at 11:25 AM, Ioannis Canellos <io...@gmail.com> wrote:
> A framework like gora should not be bound to a specific runtime, so
> solving this problem by using OSGi is a very restrictive solution.
> We should be able to use Gora on OSGi, but we should make Gora rely on it.
>
> I feel that our best shot is to find which are the dependencies that
> would satisfy all gora modules and align all our modules with those
> versions.
> It should be feasible. afaik there are frameworks with hundreds of
> components that doesn't suffer from this issue.
>
> --
> Ioannis Canellos
>
> Blog: http://iocanel.blogspot.com
> Twitter: iocanel

Re: Classloading issues in Gora

[Ioannis Canellos <io...@gmail.com>]

A framework like gora should not be bound to a specific runtime, so
solving this problem by using OSGi is a very restrictive solution.
We should be able to use Gora on OSGi, but we should make Gora rely on it.

I feel that our best shot is to find which are the dependencies that
would satisfy all gora modules and align all our modules with those
versions.
It should be feasible. afaik there are frameworks with hundreds of
components that doesn't suffer from this issue.

-- 
Ioannis Canellos

Blog: http://iocanel.blogspot.com
Twitter: iocanel