jackrabbit-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Edgar Poce <edgarp...@gmail.com>
Subject Re: jackrabbit deployment model 1
Date Thu, 14 Jul 2005 15:14:49 GMT
Hi richard

On 7/14/05, Guozhong (Richard) Wang <guozhong.wang@oracle.com> wrote:
> Julien and Marcel,
> 
> But if the internal cache is disabled as Julien did,
> in theory should multiple Repos be able to simultaneously access the
> storage?

 I don't think so. The concurrency control is done at the
SharedItemStateManager level (see
http://issues.apache.org/jira/browse/JCR-164). So, two jackrabbit
instances accessing the same physical storage will probably lead to
corrupt data. And among other problems, the search index on each
instance would be unaware of the changes made by the other, and the
observation wouldn't work as expected.

As marcel already said, clustering is not that easy

BR,
edgar

> 
> thanks,
> Richard
> 
> Julien Viet wrote:
> 
> > If you disable the cache then you reload everything all the time and
> > should achieve the desired effect, but performances will suffer a lot.
> >
> > By the way I disabled the cache in jackrabbit (I simple modified the
> > code to have the SharedItemCache have the put() do a noop).
> >
> > Some tests were not passing with that change. I think it is not normal
> > to have the tests failing when the cache is disabled (even if it
> > is uses a hack to make it not effective)
> >
> > Marcel Reutegger wrote:
> >
> >> Julien Viet wrote:
> >>
> >>> because jackrabbit uses an internal cache that you cannot disable.
> >>
> >>
> >>
> >> and even if you would be able to disable the cache, one instance had
> >> to tell the other one that something has changed on disc. otherwise
> >> you would have to scan the filesystem all the time for possible changes.
> >>
> >> clustering is not that easy ;)
> >>
> >> regards
> >>  marcel
> >>
> >
> >
> 
>

Mime
View raw message