通过JRaft简单使用raft选举

依赖：

<dependency>
  <groupId>com.alipay.sofa</groupId>
  <artifactId>jraft-core</artifactId>
  <version>1.3.14</version>
</dependency>

StateMachine.java:

@Slf4j
public class StateMachine extends StateMachineAdapter {

  private final String name;

  public StateMachine(String name) {
    this.name = name;
  }


  @Override
  public void onApply(Iterator iterator) {

  }

  @Override
  public void onLeaderStart(long term) {
    log.info(name + "become leader");
  }

  @Override
  public void onLeaderStop(Status status) {
    log.info(name + "end leader");
  }

  @Override
  public void onStopFollowing(LeaderChangeContext ctx) {
    log.info(name + "stop following leader");
  }

  @Override
  public void onStartFollowing(LeaderChangeContext ctx) {
    log.info(name + "start following leader");
  }
}

主要流程：

public class Main {
  public static void main(String[] args) {
    int id = Integer.parseInt(args[0]);
    List<PeerId> peerIdList = new ArrayList<>();
    Configuration conf = new Configuration();
    for (int i = 0; i < 2; i++) {
      PeerId p = new PeerId("localhost", 6000 + i);
      peerIdList.add(p);
      conf.addPeer(p);
    }


    PeerId serverId = peerIdList.get(id);
    NodeOptions nodeOptions = new NodeOptions();
    nodeOptions.setLogUri("raftLog");
    nodeOptions.setRaftMetaUri("raftMeta");
    nodeOptions.setInitialConf(conf);
    nodeOptions.setFsm(new StateMachine(serverId.toString()));

    Node node = RaftServiceFactory.createRaftNode("group", serverId);

    NodeManager.getInstance().addAddress(serverId.getEndpoint());

    node.init(nodeOptions);

    RpcServer rpcServer = RaftRpcServerFactory.createRaftRpcServer(serverId.getEndpoint());
    rpcServer.init(null);


  }
}

参考文档：JRaft 用户指南 · SOFAStack