/*
* Copyright 2015 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License
*/
package io.atomix.examples.election;
import io.atomix.AtomixReplica;
import io.atomix.catalyst.transport.Address;
import io.atomix.catalyst.transport.netty.NettyTransport;
import io.atomix.copycat.server.storage.Storage;
import io.atomix.group.DistributedGroup;
import io.atomix.group.LocalMember;
import java.util.ArrayList;
import java.util.List;
/**
* Leader election example.
*
* @author <a href="http://github.com/kuujo>Jordan Halterman</a>
*/
public class LeaderElectionExample {
/**
* Starts the server.
*/
public static void main(String[] args) throws Exception {
if (args.length < 2)
throw new IllegalArgumentException("must supply a path and set of host:port tuples");
// Parse the address to which to bind the server.
String[] mainParts = args[1].split(":");
Address address = new Address(mainParts[0], Integer.valueOf(mainParts[1]));
// Build a list of all member addresses to which to connect.
List<Address> cluster = new ArrayList<>();
for (int i = 1; i < args.length; i++) {
String[] parts = args[i].split(":");
cluster.add(new Address(parts[0], Integer.valueOf(parts[1])));
}
// Create a stateful Atomix replica. The replica communicates with other replicas in the cluster
// to replicate state changes.
AtomixReplica atomix = AtomixReplica.builder(address)
.withTransport(new NettyTransport())
.withStorage(new Storage(args[0]))
.build();
// Open the replica. Once this operation completes resources can be created and managed.
atomix.bootstrap(cluster).join();
// Create a leader election resource.
DistributedGroup group = atomix.getGroup("group").get();
// Join the group.
LocalMember member = group.join().get();
// Register a callback to be called when the local member is elected the leader.
group.election().onElection(term -> {
if (term.leader().equals(member)) {
System.out.println("Elected leader!");
}
});
// Block while the replica is open.
for (;;) {
Thread.sleep(1000);
}
}
}