Re: RMI Not Scalable?

Hi, I'd like to know if there's any difference in the use of internal
and external IP address of using firewall  Thanks!

On 6/26/05, Robert DiFalco <[email protected]> wrote:
> More and more I am finding RMI to not be a scalable solution for me. For
> example, I have a system that could have upwards of 5000 hosts. While
> there is only one server in the classic sense, the other nodes have
> callbacks so they are also technically RMI servers and clients.
> 
> The communication between all these hosts and the "server" use a pretty
> classic model to minimize concurrent socket usage on the "server". There
> are async calls that just deposit runnable object into the server's
> thread queue and return and sync calls that do the same thing but also
> register a listener in a local thread waiting for a callback. In this
> way, for long sync tasks the socket only needs to be open long enough to
> deposit the runnable, and the "server" then notifies the client who is
> blocking for response on a callback object. 
> 
> 
> C sends task (including callback) to S 
>         -- the connection is done afterwards
> C waits in local thread pool for the callback 
>         -- requires no connection to S
> S completes task an sends result to C using callback 
>         -- a new connection just for the callback
> 
> 
> The problem is that even with a few hundred C hosts, the "server" can
> get an incredible number of threads for RMI Connection,
> ConnectionExpiration, and RenewClean. 
> 
> So while I've designed my system to minimize the amount of long-lived
> sockets (which is pretty important) I've created a new problem which is
> a buttload of threads on the "server".
> 
> So my questions are this. 
> 
> 1. Should I just stop using RMI? I could always use my
> RMISSLSocketFactory directly and use Marshaled objects directly --
> bypassing RMI completely.
> 
> 2. If I know that my C Remote Listener and "server" remote interfaces
> are singleton instances that live as long as the application does, is
> there a way to disable (or at least minimize) the creation of RenewClean
> threads?
> 
> 3. Why is there a different thread for each ConnectionExpiration on the
> "server"? I would think there would be just one thread for ALL endpoints
> and I would only spawn a thread when I need to do something (like
> expiration), otherwise there would be just one expiration thread.
> 
> My guess is that RMI is wired so tightly that there is no way for me to
> change the way #2 or #3 work, so that brings me back to #1.
> 
> R.
> 
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To unsubscribe, send email to [email protected] and include in the body
of the message "signoff RMI-USERS".  For general help, send email to
[email protected] and include in the body of the message "help".

For a list of frequently asked RMI questions please refer to:
http://java.sun.com/j2se/1.3/docs/guide/rmi/faq.html

To view past RMI-USERS postings, please see:
http://archives.java.sun.com/archives/rmi-users.html