Sorry, you are right, I must have been daydreaming, of course it is Tyrex.
Anatoly.
On Fri, 9 Mar 2001, Stefan Siprell wrote:
> do you mean tyrex?
>
> -----Ursprungliche Nachricht-----
> Von: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]Im Auftrag von Anatoly Akkerman
> Gesendet: Freitag, 9. Marz 2001 03:43
> An: JBoss-Dev
> Betreff: RE: [jBoss-Dev] CL: Clustering, let's get started
>
>
>
> Hi,
>
> I've been following this thread for the past couple of days and wanted to
> suggest the following. There seems to be a discussion about the need of
> DTM implementation for JBoss. Well, I've ran into this lack of DTM support
> with my experiments with PetStore (see my post about Distributed
> Transactions). So, I went and looked into it a bit more.
>
> Here is what my be a reasonable alternative to implementing a DTM from
> scratch: at least for the short term we can do a very simple thing --
> piggyback ourselves on Tyger -- DTM from exolab.org. It is well-tested and
> close to 1.0 release. Since it conforms to JTA and other necessary specs,
> it should be easy to integrate it into JBoss as an MBean. As Ole Husgaard
> wrote in a reply to me, it is a matter of implementing a few classes and
> cleaning up interceptor code from using JBossTM-specific calls.
>
> I have not yet looked into Tyger's source code and how it is tied to other
> things. Perhaps, those who are interested may poke around it as well and
> see how would it fit into the overall scheme.
>
> Anatoly Akkerman
>
> On Thu, 8 Mar 2001, Tom Cook wrote:
>
> > Cool. I haven't really the first idea where to start on it, but I do have
> > time now, so I'll start looking into DTMs.. anyone else out there looking?
> >
> > Tom
> >
> > On Wed, 7 Mar 2001, marc fleury wrote:
> >
> > > Ok, time to be more precise...
> > >
> > > Assume a client talking directly to the bean, and load balance SSB.
> When
> > > THAT is done we will get B2B calls that need DTM. XP methodology. Don't
> > > stop.
> > >
> > > We know all that :) YES trivially if you deploy to n nodes, and you do
> > > nothing about "keep beans of an app in one node" and you do B2B, then
> you
> > > need a DTM.
> > >
> > > In clear I specifically want to avoid what mr cook is talking about. 10k
> > > feet "approach" talk. We need this and that oh but first bla bla.. XP!
> > >
> > > If DTM is your thing then please work on it since we will need it at the
> > > end. But in terms of approach I want to think of SSB direct clustering
> :)
> > >
> > >
> > > marc
> > >
> > > |-----Original Message-----
> > > |From: [EMAIL PROTECTED]
> > > |[mailto:[EMAIL PROTECTED]]On Behalf Of Jeremy Boynes
> > > |Sent: Wednesday, March 07, 2001 1:35 AM
> > > |To: [EMAIL PROTECTED]
> > > |Subject: RE: [jBoss-Dev] CL: Clustering, let's get started
> > > |
> > > |
> > > |Tom's question was really about approach rather than solutions and you
> did
> > > |ask for views... You might choose a "simple" scenario such as pure SSBs
> > > |first, but I tend to agree with Tom that you should consider the core
> > > |building blocks (e.g. DTM, cluster membership, resource location, state
> > > |replication, and many more) whilst doing so as in reality none of the
> > > |scenarios are actually that simple.
> > > |
> > > |
> > > |As for applicability of a DTM, one of the goals of a cluster is
> location
> > > |transparency (at least to the application). So consider a cluster with
> two
> > > |nodes, 1 & 2, and two SSBs A & B; SSB A calls a method on SSB B; SSB A
> is
> > > |deployed to node 1, SSB B to node 2.
> > > |
> > > |So if a client invokes SSB A, it is directed by availability to node 1.
> SSB
> > > |A calls SSB B and is directed by availability to node 2. You now have
> more
> > > |than one node involved which requires a distributed transaction.
> > > |
> > > |Now make it more complex, deploy SSB A on both node 1 and node 2 so the
> > > |client could be load balanced to either node. If it goes to node 1 then
> you
> > > |have a distributed transaction as above whereas if it is directed to
> node 2
> > > |then the transaction is local to node 2.
> > > |
> > > |Take it further and deploy both beans on both nodes. The client can get
> > > |load-balanced to either node; in theory so could the inter-bean
> > > |call but due
> > > |to the overhead of a remote call + DTM you would prefer it was directed
> to
> > > |the local machine.
> > > |
> > > |However, suppose SSB B becomes temporarily unavailable on one node for
> some
> > > |reason; availability would require that the inter-bean call is now
> directed
> > > |to the surviving node. The determination of which node will service the
> > > |request is dynamic, based on availability, and as a result so is the
> > > |determination of whether the transaction is local or distributed.
> > > |
> > > |If you plan to support scenarios beyond the most basic, you *will* need
> a
> > > |DTM so design it in early.
> > > |
> > > |Jeremy
> > > |
> > > |-----Original Message-----
> > > |From: [EMAIL PROTECTED]
> > > |[mailto:[EMAIL PROTECTED]]On Behalf Of marc fleury
> > > |Sent: Tuesday, March 06, 2001 7:18 PM
> > > |To: JBoss-Dev
> > > |Subject: RE: [jBoss-Dev] CL: Clustering, let's get started
> > > |
> > > |
> > > |what does a dtm have to do with Stateless session bean load balancing
> and
> > > |high availability....
> > > |
> > > |?
> > > |
> > > |marc
> > > |
> > > |
> > >
> > >
> > >
> >
> > --
> > "If you mess with something for long enough it will break." - Schmidt
> >
> >
> >
>
>
>
>
>
