> I would have thought that the notifications, security, lifecycle management, > and statefulness of either GT3 or WSRF to work reasonably well for what we're > doing, although I don't claim to be an expert on the subject. > > What are the specific weaknesses that you see with the current design (that > are due to the use of web services and globus)?
The problem is it's extremely easy to confuse globus about state. Try this: login to an AG session on one machine, proceed to another machine and login to another session. Now, on the first machine kill -9 the original session. Notice that the session still exists in the other AG client. Restart the session. You now have two instances of the first session; the old one will remain for a few minutes. Do again for three. Do in a loop to bog the server down to a crawl. (This isn't hypothetical, by the way, I've seen this happen with a buggy client.) This isn't a problem using the statefulness of a connection-oriented protocol; killing the client causes the OS to kill the connection which kills the session on the server. The irony is that Globus implements statefulness on top of stateless protocols (HTTP/web-services), which are implemented by making and breaking stateful connections (TCP). The question is why don't we just use the extremely well understood semantics of TCP to maintain connection state? I should point out that I'm not saying that there's a fundamental problem with the globus/ws architecture itself, just that it's a poor match for the AG. Cheers, Steve
