[keycloak-dev] Hybrid store committed

[Stian Thorgersen]

At some point we'll probably have to run on a trimmed down WildFly (no JavaEE stuff). Not sure if the transaction manager would still be there though.

----- Original Message -----
> From: "Bill Burke" <bburke at redhat.com>
> To: "Marek Posolda" <mposolda at redhat.com>, "Stian Thorgersen" <stian at redhat.com>
> Cc: keycloak-dev at lists.jboss.org
> Sent: Tuesday, 8 July, 2014 4:01:18 PM
> Subject: Re: [keycloak-dev] Hybrid store committed
> 
> 
> 
> On 7/8/2014 10:46 AM, Marek Posolda wrote:
> > On 8.7.2014 16:12, Stian Thorgersen wrote:
> >> If we used beans and container managed transactions then it might do
> >> that. It may also just create multiple transactions and do a 2PC. But,
> >> we don't, we start/commit our own transactions in Hibernate, and at
> >> the moment we explicitly create multiple transactions.
> >>
> >> Before I'll start this I'll check what happens. I'm sure I can
> >> relatively easily add some debug statements for when jdbc connections
> >> and transactions are created.
> >>
> >> It may also be better for us to create a UserTransaction and have the
> >> EM's enlist with that, instead of managing our own. That way we would
> >> get proper 2PC when its supported. That may be a bit overkill though,
> >> as I don't think we'd often want to update multiple databases at the
> >> same time.
> > +1 to use UserTransaction and JTA. I think earlier or later we may need
> > to support 2PC anyway. Also AFAIK with JTA the jdbc connection is
> > created "lazily" with Hibernate. In details if
> > "hibernate.current_session_context_class" is "thread" (which is by
> > default) then new JDBC connection is always opened when calling
> > "hibernateSession.getTransaction().begin()" . But when
> > "hibernate.current_session_context_class" is "jta" it retrieves JDBC
> > connection lazily when DB call is needed by Hibernate.
> >
> > At least, last time I used this, it behaved this way. I used plain
> > hibernate API though (not JPA EntityManager), but I don't think that the
> > behaviour is different with JPA.
> >
> > With respect to the fact that we have caching layer, there may be many
> > HTTP requests, which won't need to open JDBC connection, which might be
> > nice performance gain IMO.
> >
> 
> UserTransaction and JTA would make things easier.  CDI would make things
> easier too.
> 
> My only concern is that we've just narrowed where Keycloak can be
> deployed.  Currently, its not to much of a leap to install Keycloak,
> Hibernate and Resteasy on Tomcat.
> 
> 
> --
> Bill Burke
> JBoss, a division of Red Hat
> http://bill.burkecentral.com
>