Sounds cool.. but I think that JMS CAN do most of that stuff. It's all in
how it's implemented. In the JBossMQ CVS we already have a working
Multicast JMS server. This server is different than the normal JBossMQ JMS
server, I'm calling this one JBossMQ-Cluster. That's because I'm aiming to
optimize it for operating in clustered environments. In other works
JBossMQ-Cluster will not support persistence, queues, durable subscriptions,
message priorities, or transactions to name a few missing features. It's
going to provide FAST publish-subscribe services via multicast. What does
it do now that java groups does? :
* losses transmission of a message to all recipients (with retransmission
of missing messages)
* fragmentation of large messages into smaller ones and reassembly at the
receiver's side ordering of messages, e.g. messages m1 and m2 sent by P
will be received by all receivers in the same order, and not as m2, m1
(FIFO order)
Using the above features and the standard JMS publish-subscribe services, I
think we can build all the other features quickly. The only non standard
JMS extension we would have to use is so that app could get notified when a
peer failure is detected by the JMS Server.
I've started working on a class that keeps a list which peers are active in
the cluster. It should not be too hard to extend that so that it provides
some similar "group" notification services such as the ones provided by
javagroups.
Regards,
Hiram
P.S. I have looked at the Javagroups site and they do have a WAY better
multicast implementation. I think I'm going to have to steal a few Ideas
from over there ;-) But the point of the e-mail was that: I think a
framework around JMS can be implemented which will provide all the services
that we will need.
----- Original Message -----
From: "Filip Hanik" <[EMAIL PROTECTED]>
To: "JBoss-Dev" <[EMAIL PROTECTED]>
Sent: Friday, March 09, 2001 11:52 AM
Subject: RE: [jBoss-Dev] CL: Clustering, let's get started
> I wasn't aware that JMS could
>
> a) allow you to modify/customize the protocol stack
> b) provide notification of members that joins, leaves or crashes
> c) atomicity
>
> these are the big things, I would like to hear what info you have one JMS
> over multicast
>
> Filip
> ------8<-----------------------------------------------------------
>
> JavaGroups is a group communication toolkit written entirely in Java. It
is
> based on IP multicast, but extends it with reliability and group
> membership.
>
> Reliability includes
> * lossless transmission of a message to all recipients (with
retransmission
> of missing messages)
> * fragmentation of large messages into smaller ones and reassembly at the
> receiver's side ordering of messages, e.g. messages m1 and m2 sent by P
> will be received by all receivers in the same order, and not as m2, m1
> (FIFO order)
> * atomicity: a message will be received by all receivers, or none.
>
> Group Membership includes
> * Knowledge of who the members of a group are and
> * Notification when a new member joins, an existing member leaves, or an
> existing member has crashed
>
>
>
> ~
> Namaste - I bow to the divine in you
> ~
> Filip Hanik
> Software Architect
> [EMAIL PROTECTED]
> www.filip.net
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Hiram Chirino
> > Sent: Friday, March 09, 2001 11:44 AM
> > To: JBoss-Dev
> > Subject: Re: [jBoss-Dev] CL: Clustering, let's get started
> >
> >
> >
> > I would like to know what javagroups give you that JMS over multicast
does
> > not?
> >
> > Regards,
> > Hiram
> >
> > >
> > > Yes, I read up on JavaGroups, it is a brilliant idea. if anyone of you
> > > haven't taken a look at it yet,
> > > goto www.javagroups.com
> > >
> > > the idea of building your own stack on top of their technology is very
> > > appealing to me.
> > >
> > > Furthermore, the idea of groups will blow away an implementation like
> > > Weblogic that uses IP multicast and heart beats to determine whether a
> > > server is up or down. Javagroups has that capability built in already.
> > > not trying to be competitive, just comparative. :)
> > >
> > >
> > > Tom and Sacha, great ideas and great work!
> > >
> > > ~
> > > Namaste - I bow to the divine in you
> > > ~
> > > Filip Hanik
> > > Software Architect
> > > [EMAIL PROTECTED]
> > > www.filip.net
> > >
> > >
> > >
> >
> >
>
>
>
