Chris Harris wrote: > Using JMS, you simply make sure that where a significant > change happens to an EJB, a message is published to a JMS > Topic.
So far so good. Makes sense. I notice here you've left out the MDBs that were mentioned in the previous email. That one had me a little confused as to how it fitted into the basic structure. Out of all this, my biggest issue would be with performance. Say you have 20-30 application clients accessing your EJBs (let's say entity beans). There's probably at any one time 5,000 beans active with values being changed, loaded and stored. How well would the JMS systems handle that amount of traffic? I suspect it would probably choke. This is a real world example of the project I'm working on now, which is a catalogue engine. Those numbers are a little on the low side. We're conservatively estimating 100K+ bean instances, of which approx 10-15K would be active at any one time (we know from basic testing that any given client UI will be maintaining about 5K bean references as needed - bloody huge paged JTables!). We have huge transaction requirements - particularly in import and exporting, so beans are going to be running crazy here. Each action, such as import or export is going to be creating bean instance (ejbCreate()) in bulk and also manipulating existing instances. In addition, most of the client UIs are going to be viewing that same collection of active beans, so we need a mechanism to tell the UI to update when the underlying bean instance has changed. So there's some fun performance/scalability issues that we have to benchmark. Based on a gut feel, I can't see the JMS solution being capable of handling this set of requirements. -- Justin Couch http://www.vlc.com.au/~justin/ Freelance Java Consultant http://www.yumetech.com/ Author, Java 3D FAQ Maintainer http://www.j3d.org/ ------------------------------------------------------------------- "Humanism is dead. Animals think, feel; so do machines now. Neither man nor woman is the measure of all things. Every organism processes data according to its domain, its environment; you, with all your brains, would be useless in a mouse's universe..." - Greg Bear, Slant ------------------------------------------------------------------- =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
