RMI timeout

[Yemi Dalley]

Hello all,

I'm rounding off my URLyBird assignment but i've noticed that the client just waits forever whenever the server is no longer unavailable. Is there a way to set a time out, after which the proxy throws an appropriate exception ?

Thanks

[Alex Belisle Turcot]

Hi,

I'm at work and can't try it.. but you got me thinking and wanted to know for myself, and I found this :

RMI Naming.loookup timeouts

Could you please tell me if that solved the problem ?

Regards,
Alex

[Nitesh Kant]

Originally posted by Alex Belisle Turcot:

RMI Naming.loookup timeouts

I dont think Naming.lookup will hang forever if the server is not available.
If i understand you correctly, then what you require is that if a method call does not complete within a stipulated time period, it should throw an exception. If this is what you are referring to then, you need to write your own RmiClientSocketFactory and set the socket timeout to a desired value for every socket created.
The following code may help:

 
import java.io.IOException;
import java.io.Serializable;
import java.net.Socket;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.server.RMISocketFactory;
 
/**
 * An rmi socket factory that honours a timeout interval for any client requests to the remote object.
 * This factory can be used to configure a timeout period for an rmi call.
 *
 * @author: Nitesh Kant
 */
public class ClientSocketFactory implements RMIClientSocketFactory, Serializable {
 
    private int timeOutPeriod;
 
    private static final long serialVersionUID = -2275404716409167116L;
 
    public ClientSocketFactory(int timeOutPeriod) {
        this.timeOutPeriod = timeOutPeriod;
    }
 
    public Socket createSocket(String host, int port) throws IOException {
        Socket socket = RMISocketFactory.getDefaultSocketFactory().createSocket(host, port);
        socket.setSoTimeout(timeOutPeriod);
        return socket;
    }
 
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
 
        final ClientSocketFactory that = (ClientSocketFactory) o;
 
        return timeOutPeriod == that.timeOutPeriod;
 
    }
 
    public int hashCode() {
        return timeOutPeriod;
    }
}
  

This link will also help.

[Musab Al-Rawi]

hi,

Although this sounds very interesting but don't you think that this is not part of the requirements.
if it not part of the your requirements consider my humble advice of leaving this part till the end after you make sure that everything required is working perfectly.

[Yemi Dalley]

thanks guys ;
It's very interesting indeed ..
my problem was because i didn't unexportObject the remote object , i only called unbind.

After calling unexportObject the default timeout seems to be ok.

[Fors Judd]

Thanks for the careful and complete piece of code.
But due to my own mountainous confusion, I do not see when or where to use this thing.

Nitesh Kant wrote:
public class ClientSocketFactory implements RMIClientSocketFactory, Serializable { ... }

Must it happen before the UnicastRemoteObject gets constructed? or after?
just once? or as often as you like?
How does it relate to RMISocketFactory? Does it get bundled up and handed off to setSocketFactory somehow?
And does this solution pertain only to certain versions of Java?

[Fors Judd]

Also note that both these links are dead:
"RMI Naming.loookup timeouts"
"This link will also help."