Re: [xmlblaster] Clustering XmlBlaster Servers ?

[Hugues Jerome <hugues at email.enst.fr>]

Marcel Ruff (ruff at swand.lake.de):

> Could you explain the different approaches in more depth?

Here are some information I've gathered

I think the term clustering I used is rather confusing, let just call it 
"a set of nodes communicating to provide the raw functionnalities for a mom : 
delivering a message from a point to another", just as Usenet servers around 
the world delivers posts ...

> What is the joram and openjms approach in clustering
> what do they want to achieve with a cluster?
> 
> What is a 'cluster' in their view?
> - Is is load balancing
> - Fail over
> - ??

* For OpenJMS, from their datasheet :

"Scalability and high-availability concerns are addressed through a peer-to-peer communication protocol between servers. This feature allows multiple servers to be connected together to build a federation, facilitating inter-server client communication."
Here, 'servers' means a node running an instance of OpenJMS

The use of a peer-to-peer architecture may help in deploying and dynamically
configuring vast networks. Due to a lack of documentation about OpenJMS, I 
cannot tell more :( , though I'm trying to get more info from the developpers
 ...


* For JORAM, from their datasheet and papers about the AAA framework :

JORAM uses a lower layer called AAA (Agent Anytime Anywhere). Agents are
proactive objects naturally distributed, piece of code that can migrate from
node to node, that can be persistant ... 

ObjectWeb simulated 10000 nodes on the server side using this technology
This helps to provide : 
- topic clustering to reduce bandwidth (think  about a widely distributed app,
 in term of space), 
- persistency and agents provide fault tolerance
- agents provide potentially dynamic reconfiguration through the migration of 
agents
=> load balancing/fault tolerance

info, through citeseer (http://citeseer.nj.nec.com/)
search for the following papers :

- An Agent Platform for Reliable Asynchronous Distributed Programming
L. Bellissard , N. De Palma, A.Freyssinet , M. Herrmann, S. Lacourte 
Sirac Project and AAA-Dyade, INRIA Rhne-Alpes
- The AAA Agent-based Message Oriented Middleware
(same team)
- Dynamic Reconfiguration of Agent-Based Applications

JORAM 3.0 was released last week, give a look at the sample page to see
what Joram can do (http://www.objectweb.org/joram/current/doc/samples/)


I'm still gathering information, so please be patient, I cannot write an in
depth description of these topics at this moment, but be sure I will !

Hope this helps ...

-- 
Jerome