On Tue, Dec 1, 2009 at 1:27 AM, philippe van dyck <[email protected]> wrote:
> I plan to try this on EC2 later, in order to validate the usability, hoping > that a local network will remove the current performance problem. Well, has all the discussion so far been around having S3 accessed from a "local" system? I can understand that adding Infinispan (or any other LAN based cache) would greatly improve performance in such case, due to latencies between your LAN and S3. As for XA transaction isolation, I am a bit skeptical, since IIUIC all instances needs to participate in all transactions, and that doesn't scale. Instead, what I think I have concluded is that Entity Aggregates are the way to go, i.e. no changes to any entities other than via the Aggregate. The "problem" is "how to do it". One way is to direct all requests regarding a particular Aggregate to the same node, but theoretically that node may be available to some clients and not others, causing fail-over to send the requests to the wrong node. "Communication channels" between nodes don't really work, since one node may have already "be done" with an aggregate when another node starts working on it, without those changes to be visible at the second node. Another option would be to not allow any changes, only additions (provided that S3 can handle atomic additions), and resolve the state in higher level code. For some systems there could be an explosion of storage, which could be solved by having a kind of GC chewing along in the background. Another option would be to ignore it all... Cheez, not sure what to make of it all... Cheers -- Niclas Hedhman, Software Developer http://www.qi4j.org - New Energy for Java I live here; http://tinyurl.com/2qq9er I work here; http://tinyurl.com/2ymelc I relax here; http://tinyurl.com/2cgsug _______________________________________________ qi4j-dev mailing list [email protected] http://lists.ops4j.org/mailman/listinfo/qi4j-dev
