[Engine-devel] Ideas about engine clustering?

[Liran Zelkha]

IMHO EJB clustering is not the direction we should take, especially considering our IoC plans (see http://gerrit.ovirt.org/#/c/5575/).
QuartzScheduler can be easily fixed by using a DB for Quartz configuration. We had such a discussion a few weeks ago.
mod_jk is probably better for our HA.
Postgres clustering should probably be a different task, as it's more infra and less code.

Another thing to consider is locking, currently done using synchronized, and will need to be changed somehow (probably using Infinispan).

On Aug 22, 2013, at 10:22 AM, Itamar Heim wrote:

> On 08/21/2013 10:27 PM, plysan wrote:
>> 
>> 
>> 
>> 2013/8/22 Itamar Heim <iheim at redhat.com <mailto:iheim at redhat.com>>
>> 
>>    On 08/21/2013 11:08 AM, plysan wrote:
>> 
>> 
>> 
>> 
>>        2013/8/21 Laszlo Hornyak <lhornyak at redhat.com
>>        <mailto:lhornyak at redhat.com> <mailto:lhornyak at redhat.com
>>        <mailto:lhornyak at redhat.com>>>
>> 
>> 
>>             Hi,
>> 
>>             ----- Original Message -----
>>              > From: "plysan" <plysab at gmail.com
>>        <mailto:plysab at gmail.com> <mailto:plysab at gmail.com
>>        <mailto:plysab at gmail.com>>>
>>              > To: engine-devel at ovirt.org
>>        <mailto:engine-devel at ovirt.org> <mailto:engine-devel at ovirt.org
>>        <mailto: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)**
>> 
>> 
>> 
>>              >
>>              > Any ideas?
>>              >
>>              > Thanks!
>>              >
>>              > _________________________________________________
>>              > Engine-devel mailing list
>>              > Engine-devel at ovirt.org <mailto:Engine-devel at ovirt.org>
>>        <mailto:Engine-devel at ovirt.org <mailto:Engine-devel at ovirt.org>__>
>>              > http://lists.ovirt.org/__mailman/listinfo/engine-devel
>>        <http://lists.ovirt.org/mailman/listinfo/engine-devel>
>> 
>>              >
>> 
>> 
>> 
>> 
>>        _________________________________________________
>>        Engine-devel mailing list
>>        Engine-devel at ovirt.org <mailto:Engine-devel at ovirt.org>
>>        http://lists.ovirt.org/__mailman/listinfo/engine-devel
>>        <http://lists.ovirt.org/mailman/listinfo/engine-devel>
>> 
>> 
>>    unless you need the load balancing, just for HA, hosted-engine
>>    should cover your needs?
>> 
>> I think failover and more scalability  is what i am interested here.
>> Just thinking about the possibilities :)
>> Imagine engine would never get restarted from outside view. Cool isn't it?
> 
> active/passive failover you should get from hosted-engine (yes, with some downtime)
> scalability and active-active would be great. iirc, juan looked at implications of doing this a while back
> _______________________________________________
> Engine-devel mailing list
> Engine-devel at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/engine-devel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/devel/attachments/20130824/3702b501/attachment-0001.html>