to put a tie around all of my complaining, I would also volunteer to create
a dcoument describing the main ideas and concepts:
-Round Robin (kind of low, but the one that would create working versions
the fastest)
-Bean-level Request Dispatching
-CORBA infrastructure
-and maybe JINI and SPACES (my little idea)
Might be easier to discuss (if required at all) the future path.
-----Ursprungliche Nachricht-----
Von: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]Im Auftrag von Peter F. Spicer
Gesendet: Mittwoch, 7. Marz 2001 16:39
An: JBoss-Dev
Betreff: RE: [jBoss-Dev] CL: Clustering, let's get started
Lots of good feedback on the Clustering issue. Anybody thought about
putting together a requirements document that captures these ideas and
defines "The Path" for the effort? Does not have to be fancy - I would
volunteer but don't have the chops (domain expertise).
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Micheal J
Sent: Wednesday, March 07, 2001 6:41 AM
To: JBoss-Dev
Subject: RE: [jBoss-Dev] CL: Clustering, let's get started
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Jeremy Boynes
> Sent: 07 March 2001 06:35
> 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.
My definition of application server clustering does not allow a situation as
you just described Jeremy. The beans (actually the application) would be
deployed to the "cluster" and not to any particular node (or nodes) in a
cluster. On an implemenatation level, I would still expect all nodes to host
all applications once deployed. This removes the possibility of any
application being unavailable even though a cluster is atill active. This
could happen if either node 1 or node 2 failed in your example.
Also I believe we need to think about the jBoss clustering effort in the
wider context of clustering complete J2EE applications. Perhaps I am missing
something here but shouldn't think about how a cluster-capable jBoss affects
jBoss-Tomcat and/or jBoss-Jetty and other such (aggregated) J2EE stacks?.
My Use Cases for a "JBoss Cluster User" includes :
- Cluster Management: define/change the set of nodes (JBoss only or
JBoss_+_Tomact/Jetty/etc) that belong together as a cluster
- Application Deployment: deploy a JAR, WAR, EAR e.t.c on a node (any node?)
in a jBoss-Tomcat (or jBoss-Jetty) cluster and have the application
automagically deployed (and load-balanced) across all the nodes in the
cluster. I presume that there would be a deployment tool for this purpose
and that hot-deploy may or may not work (it would be great if it did
though).
Issues:
- WHAT IS DEFINED AS A NODE IN THE CLUSTER?
a) A physical computer running jBoss ?
A cluster is then a named set of physical computers. This raises
questions such as "must all instances (i.e. on different port nos)
of jBoss on these computers be automatically clustered?".
b) A specific instance (identified by port no) of JBoss running on a
specified port on a physical computer?.
A cluster may be all instances of jBoss running on the same port on
a specified set of physical computers. If the instances are truly
isolated, one can run a dev, test and staging cluster on the same
set of physical computers for instance. I use multiple instances
in this way with Oracle and SQL Server currently.
- WHICH APPLICATION RESOURCES CAN BE CLUSTERED?
* EJB Jars only ?
* WAR, EAR ??
* other files ???
Cheers!,
Micheal
