EJB fail-over
Hello,
I have the following situation:
1. Two JBoss 4.0.2 servers running on WinXP PRO and Suse 9.2 configured as a cluster using the all configuration
2. I create a very simple EAR containing a stateful session bean with the clusterable attribute set in the deployment descriptor and deployed by farming to both application servers.
3. A simple J2SE client application (command line) that connects to the session bean and calls a string returning "Hello-World"-like method.
Both members in the cluster are aware of eachother because when the client application creates several instances to the session bean, they are load-balanced between the two servers.
The problem occures when I shutdown one of both instances of Tomcat. Connections made to this server get lost although I would like to use the remaining to process the requests. It seems that fail-over is not working for my configuration. Does anyone know some good documents/examples to achieve this kind of behaviour? I really like JBoss so it would be a pitty to notice that such stuff would not be possible ;-)
Thanks for the advise !!!!
Regards,
Kurt
The client application
package client;
import java.util.*;
import javax.naming.*;
import javax.rmi.*;
import server.ejb.*;
public class ClusterClient {
public ClusterClient() {
for(int j = 0 ; j < 5 ; j++){
Runnable runner = new ClusterClientRunner();
Thread thread = new Thread(runner, "Runner " + j);
thread.start();
try{
Thread.sleep(1000);
}catch(InterruptedException e){
}
}
}
private class ClusterClientRunner implements Runnable{
public void run(){
System.out.println(Thread.currentThread().getName() + " started.");
try{
Properties props = new Properties();
props.setProperty(Context.INITIAL_CONTEXT_FACTORY,
"org.jnp.interfaces.NamingContextFactory");
//props.setProperty(Context.PROVIDER_URL,
// "192.168.3.120:1100,192.168.3.159:1100");
Context ctx = new InitialContext(props);
StatefullSessionRemoteHome home = (StatefullSessionRemoteHome)
PortableRemoteObject.narrow(
ctx.lookup("StatefullSessionBean"),
StatefullSessionRemoteHome.class);
StatefullSessionRemote bean = home.create();
for(int i = 0 ; i < 20 ; i++){
System.out.println(Thread.currentThread().getName() + " triggering with ID = " + i);
bean.executedAt(Thread.currentThread().getName() + " triggering with ID = " + i);
try{Thread.sleep(2500);
}catch(InterruptedException e){}
}
}catch(Exception ex){
ex.printStackTrace();
}
System.out.println(Thread.currentThread().getName() + " completed.");
}
}
public static void main(String[] args) {
new ClusterClient();
}
}
The session bean's code
package server.ejb;
import javax.ejb.*;
import javax.naming.*;
public class StatefullSessionBean implements javax.ejb.SessionBean, server.ejb.StatefullSessionRemoteBusiness, server.ejb.StatefullSessionLocalBusiness {
private javax.ejb.SessionContext context;
private static int counter;
public void setSessionContext(javax.ejb.SessionContext aContext) {
context = aContext;
}
public void ejbActivate() {
}
public void ejbPassivate() {
}
public void ejbRemove() {
}
public void ejbCreate() {
}
public String showMessage() {
StringBuffer buffer = new StringBuffer();
buffer.append("Bean executed at : " + (String)System.getProperty("server"));
System.out.println(counter + " == " + buffer.toString());
counter++;
return buffer.toString();
}
public void executedAt(java.lang.String location) {
System.out.println("Triggered by : " + location);
}
}
The deployment descriptor
<?xml version="1.0" encoding="UTF-8"?> <jboss> <enterprise-bean> <session> <ejb-name>StatefullSessionBean</ejb-name> <jndi-name>StatefullSessionBean</jndi-name> <clustered>True</clustered> <cluster-config> <partition-name>DefaultPartition</partition-name> <home-load-balance-policy> org.jboss.ha.framework.interfaces.RoundRobin </home-load-balance-policy> <bean-load-balance-policy> org.jboss.ha.framework.interfaces.RoundRobin </bean-load-balance-policy> <session-state-manager-jndi-name> /HASessionState/Default </session-state-manager-jndi-name> </cluster-config> </session> </enterprise-bean> </jboss>