The basic idea is, every HEARTBEAT time, ask to RPCService which nodes still on

and compare with initial cluster config defined in floodlightdefault.properties.

Issues: Do not treat the message ROLE_STATUS.
In case a cluster goes down and goes up, there is a problem, the Controller does not change its own role to role slave.

But works properly as Primary-Backup configuration.

Under development...

src/main/java/net/floodlightcontroller/simpleft/UtilDurable.java

+package net.floodlightcontroller.simpleft;
+
+import java.util.concurrent.TimeUnit;
+
+import net.floodlightcontroller.core.IOFSwitch;
+
+import org.projectfloodlight.openflow.protocol.OFControllerRole;
+import org.projectfloodlight.openflow.protocol.OFRoleReply;
+import org.projectfloodlight.openflow.types.U64;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+public class UtilDurable {
+	private static Logger logger;
+	
+	public UtilDurable(){
+		logger = LoggerFactory.getLogger(UtilDurable.class);
+	}
+	
+	public OFRoleReply setSwitchRole(IOFSwitch sw, OFControllerRole role) {
+		try {	
+			ListenableFuture<OFRoleReply> future = sw.writeRequest(sw.getOFFactory().buildRoleRequest()
+					.setGenerationId(U64.ZERO)
+					.setRole(role)
+					.build());
+			return future.get(10, TimeUnit.SECONDS);
+
+		} catch (Exception e) {
+			logger.error("Failure setting switch {} role to {}.", sw.toString(), role.toString());
+			logger.error(e.getMessage());
+		}
+		return null;
+	}
+
+}