users@glassfish.java.net

Re: Concurrent acess to stateful sb from rich client/design question

From: <glassfish_at_javadesktop.org>
Date: Thu, 18 Oct 2007 12:31:26 PDT

Hi all,

revisiting this after a while, sorry for silence but I had a son born last week and well.. sitting at computer desk fell a little bit lower on my priority list :)

I would like to thank all of you for your comments (and time), I do appreciate that a lot.

> If you're using a client side singleton facade to the
> session bean, I don't know why synchronized access to
> all of the methods would be a bad thing. It should
> prevent the problem entirely, assuming it performs
> well enough (different issue entirely).

Yes, synchronized access resolves the problem of concurrent access.

(snip)
>
> If you're moving any real amount of data, that's
> where the synchronous impact hurts the most.

Yes, it does :(
>
> Now, something you might want to try would be to have
> a synchronization map on the server side, and facade
> the SFSB with a normal Stateless SB.
>
> The game here is that you pass the SFSB handle around
> with your other data. The SSB gets the handle, grabs
> a locking object from a cache based on the handle,
> and uses that object as a semaphore to synchronize
> access on the server side to the SFSB.

Well, this is pretty much interesting and I would like to try this. Unfortunately my googling attempts did not result in some example. And my naive attempt to code test sample failed. I am afraid I do not get exactly what you mean by the handle and how to synchronize access on server side. Any link to some further description of the pattern please?

Thanks a lot,
dale
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