io.servicefabric.examples.metadata.ClusterMetadata Maven / Gradle / Ivy
package io.servicefabric.examples.metadata;
import io.servicefabric.cluster.Cluster;
import io.servicefabric.cluster.ClusterConfiguration;
import io.servicefabric.cluster.ClusterMember;
import io.servicefabric.cluster.ICluster;
import io.servicefabric.transport.Message;
import rx.functions.Action1;
import rx.functions.Func1;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Using Cluster metadata: metadata is set of custom paramters that may be used by application developers to attach
* additional business information and identifications to cluster memebers.
*
*
* in this example we see how to attach logical alias name to a cluster member we nick name Joe
*
* @author ronen_h
*/
public class ClusterMetadata {
private static final String MESSAGE_DATA = "hello/Joe";
public static final Func1 MESSAGE_PREDICATE = new Func1() {
@Override
public Boolean call(Message message) {
return MESSAGE_DATA.equals(message.data());
}
};
/**
* Main method.
*/
public static void main(String[] args) {
ICluster seedCluster = Cluster.newInstance(3000).join();
// define the custom configuration meta data. and we add alias field.
Map metadata = new HashMap<>();
metadata.put("alias", "Joe");
ClusterConfiguration config =
ClusterConfiguration.newInstance().port(4004).seedMembers("localhost" + ":" + "3000").memberId("my_member_id")
.metadata(metadata);
// configure cluster 2 with the metadata and attach cluster 2 as Joe and join seed
ICluster joeCluster = Cluster.newInstance(config).join();
// filter and subscribe on hello/joe and print the welcome message.
joeCluster.listen().filter(MESSAGE_PREDICATE).subscribe(new Action1() {
@Override
public void call(Message message) {
System.out.println("Hello Joe");
}
});
// get the list of members in the cluster and locate Joe tell Hello/Joe
List members = seedCluster.membership().members();
for (ClusterMember m : members) {
if (m.metadata().containsKey("alias")) {
if (m.metadata().get("alias").equals("Joe")) {
seedCluster.send(m, new Message(MESSAGE_DATA));
}
}
}
}
}