Skip to main content

JXTA pub-sub system

6 replies [Last post]
glisca
Offline
Joined: 2007-05-25

Hi,

I am an undergraduate student at McGill University and I am currently working on a publisher-subscriber project and I was very interested in the JXTA framework.

However, I wonder if it can scale properly for my project: I need to be able to open several hundreds or even thousands publisher/subscriber channels on each host. I know there has been some performance analysis done on the size of the packets but I couldn’t find any on the number of channels/pipes.

Do you think that JXTA would be appropriate for such a project or should I look into other technologies?

Thank you very much for your help,

Matthieu

Reply viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
asghar
Offline
Joined: 2005-07-26

Hi Matthieu,

JXTA is made of 6 protocols, enabling hybrid model of networking (P2P & Client-Server) and Firewall & NAT traversal. It’s also available for consumer devices (smart phone, PDA), supporting Java (JXME).

JXTA platform doesn’t include such high performance (and reliable) Message Broker, what your project needs.
I think reliable message delivery is critical for proper operation of yourApp.
I took a fast look at xml Blaster. A nice product, but it seems they are still working to make it JMS-compliant. (but I’m not sure)

Take a look at [b]Apache Active MQ[/b] too http://activemq.apache.org .
It has a lot of valuable features, is JMS-conform and supports JXTA too! (for Firewall and NAT traversal).

Using a JMS-conform message broker enables you to interface the messaging-subsystem of yourApp with other services, which are conform to Java EE specifications.
I think that is important for future development of MMOG.

Asghar

glisca
Offline
Joined: 2007-05-25

Hi Asghar,

Thank you very much for your help, I will look into Apache Active MQ and see if we can use it for our program. I will also look into Pastry http://freepastry.rice.edu/ which seems to be a viable alternative.

Did the webmaster get back to you about the Mammoth login? If not send me an email and I'll talk to him to get that fixed.

Sincerely,

Matthieu

asghar
Offline
Joined: 2005-07-26

Hello Matthiue,
Your webmaster is smart. He helped me to solve the problems. Thank you.
I may have some questions in near future.
Asghar

asghar
Offline
Joined: 2005-07-26

Hi Matthieu,

1.- Can you please explain the publisher / subscriber project (or publisher / subscriber channels) a little bit more?
I maybe able to give you some useful tip.

2.- What is an alternate technology to JXTA for your project?

Asghar

glisca
Offline
Joined: 2007-05-25

Hi Asghar,

I am working on a Massive Multi-player Online Game (MMOG) with McGill University. (The Mammoth Project: http://mammoth.cs.mcgill.ca/). I am trying to redesign the networking subsystem which is based on a subscriber/publisher system. Basically each object that lives on the server creates it's own subscription channel. All the players that are interested in that object (a player is said to be "interested" in an object when that object is the area around him) subscribe to that channel. This way, every time the object is updated/moved/transformed, everyone who is in the vicinity is alerted.

This puts several constraints on the project, the main one being that the server has several thousands objects living on it and therefore it needs to be able to open several thousand channels at the same time. Similarly, on the client side, each player needs to be able to keep track of possibly thousands of objects and therefore needs to be able to sign-up to thousands of channels.

(Note: I use the notion of client-server since this what we currently have in place, but we are pushing towards a more decentralized peer-to-peer system which is one of the reasons why I am interested in JXTA).

As for alternative technologies I was thinking of something along the lines of JMS or a middleware like XMLBlaster.

Thank you for your help,

Matthieu

asghar
Offline
Joined: 2005-07-26

Hi Matthieu,

I followed the link in your previous message and noticed, that MMOG is really an interesting project!

I tried also to get a general understanding of the app. But I got 2 technical problems, which I report about to the site’s web master.
I can go on after solving these (small but blocking) problems.

At the time being, I can only say, that use of JXTA brings certainly some (new) powerful and attractive features to the system-architecture of the app.
We -all at JXTA community- will be happy, if you decide so.

Asghar