[Engine-devel] Ideas about engine clustering?

[Yair Zaslavsky]

----- Original Message -----
> From: "Laszlo Hornyak" <lhornyak at redhat.com>
> To: "plysan" <plysab at gmail.com>
> Cc: engine-devel at ovirt.org
> Sent: Wednesday, August 21, 2013 6:30:36 PM
> Subject: Re: [Engine-devel] Ideas about engine clustering?
> 
> 
> 
> ----- Original Message -----
> > From: "plysan" <plysab at gmail.com>
> > To: "Laszlo Hornyak" <lhornyak at redhat.com>
> > Cc: engine-devel at ovirt.org
> > Sent: Wednesday, August 21, 2013 5:08:57 PM
> > Subject: Re: [Engine-devel] Ideas about engine clustering?
> > 
> > 2013/8/21 Laszlo Hornyak <lhornyak at redhat.com>
> > 
> > > Hi,
> > >
> > > ----- Original Message -----
> > > > From: "plysan" <plysab at gmail.com>
> > > > To: engine-devel at ovirt.org
> > > > Sent: Wednesday, August 21, 2013 3:49:31 PM
> > > > Subject: [Engine-devel] Ideas about engine clustering?
> > > >
> > > > Hello, guys:
> > > >
> > > > I'm trying to make a jboss clustering environment for engine. But felt
> > > the
> > > > difficuty too.
> > > > So I want to know if any one is working on this? I googled it and
> > > > haven't
> > > > found anything.
> > > >
> > > > I know there will be lots of things to do for engine migrating to
> > > clustering
> > > > environment. I just want to know what problem need to be solved?
> > > > I would like to list the things I think that is needed to do(or solve):
> > > > 1. run jboss in standalone-ha mode or domain mode.
> > > > 2. add @Clustered annotation to each EJB, I think this will solve the
> > > > replication problem in cluster, probably lots of details in it.
> > > > 3. QuartzScheduler problem, only one node running a scheduler is enough
> > > at a
> > > > time instead of each node running one.
> > > > 4. use mod_cluster to handle load balancing.
> > > > 5. postgresql clustering.
> > >
> > > For failover it sounds like a plan, just wondering if this could solve
> > > load balancing problems as well.
> > > Ovirt is generating a big load on the DB and I would be really interested
> > > if SQL DB clustering could solve the issues.
> > > It would be great if it could, big part of the scalablity issue is the
> > > evil things we did against that poor database.
> > >
> > > > 6. There should be more, but hope anyone can think about it :D
> > >
> > > There are tons of data structures that are used in oVirt that store
> > > state.
> > > You will have to hunt all of these down and replace with a data structure
> > > that is shared between the cluster memebers. This may be a big lot of
> > > work
> > > from many parts of the application.
> > >
> > 
> > Indeed, and like Yair Zaslavsky said, we can put the data structure in
> > infinispan cache, but clustered EJB can do the same thing for us, right? If
> > all those state values are inside EJBs. (iirc)* *
> 
> There are only a very small number of real EJB's in oVirt, almost all and
> everything is done by singletons created by EJBs. (check
> InitBackendServicesOnStartupBean, Backend they are the biggest factories of
> these singletons)
> If you made a deeper research in this recently then your information may be
> more up to date than mine, but while working in various parts of the app I
> have found tons of local state.

That's right.
Not to mention there are some thoughts (at least by some of us) whether we really need EJBs , but that's a totally different discussion ;)

> 
> > 
> > >
> > > >
> > > > Any ideas?
> > > >
> > > > Thanks!
> > > >
> > > > _______________________________________________
> > > > Engine-devel mailing list
> > > > Engine-devel at ovirt.org
> > > > http://lists.ovirt.org/mailman/listinfo/engine-devel
> > > >
> > >
> > 
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