public void start() throws Exception {
m_leaderLatch =
new LeaderLatch(
m_client.get(),
m_config.getMetaServerLeaderElectionZkPath(),
m_config.getMetaServerName());
m_leaderLatch.addListener(
new LeaderLatchListener() {
@Override
public void notLeader() {
log.info("Become follower");
m_hasLeadership.set(false);
m_leader.set(fetcheLeaderInfoFromZk());
m_listenerContainer.notLeader(ClusterStateHolder.this);
}
@Override
public void isLeader() {
log.info("Become leader");
m_hasLeadership.set(true);
m_leader.set(fetcheLeaderInfoFromZk());
m_listenerContainer.isLeader(ClusterStateHolder.this);
}
},
Executors.newSingleThreadExecutor(
HermesThreadFactory.create("LeaderLatchListenerPool", true)));
// call notLeader before start, since if this is not leader, it won't trigger notLeader on start
m_listenerContainer.notLeader(this);
m_leaderLatch.start();
}
public void registerLeaderLatchListener(LeaderLatchListener... leaderListener) {
try {
leaderLatch.start();
Arrays.stream(leaderListener).forEach(leaderLatch::addListener);
} catch (Exception e) {
throw new InternalProcessingException(e);
}
}
public static void main(String[] args) throws Exception {
List<LeaderLatch> leaders = new ArrayList<LeaderLatch>();
List<CuratorFramework> clients = new ArrayList<CuratorFramework>();
TestingServer server = new TestingServer();
try {
for (int i = 0; i < 10; i++) {
CuratorFramework client =
CuratorFrameworkFactory.newClient(
"192.168.50.202:2181,192.168.50.203:2181,192.168.50.204:2181",
new ExponentialBackoffRetry(20000, 3));
clients.add(client);
LeaderLatch leader = new LeaderLatch(client, "/francis/leader");
leader.addListener(
new LeaderLatchListener() {
@Override
public void isLeader() {
// TODO Auto-generated method stub
System.out.println("I am Leader");
}
@Override
public void notLeader() {
// TODO Auto-generated method stub
System.out.println("I am not Leader");
}
});
leaders.add(leader);
client.start();
leader.start();
}
Thread.sleep(Integer.MAX_VALUE);
} finally {
for (CuratorFramework client : clients) {
CloseableUtils.closeQuietly(client);
}
for (LeaderLatch leader : leaders) {
CloseableUtils.closeQuietly(leader);
}
// CloseableUtils.closeQuietly(server);
}
Thread.sleep(Integer.MAX_VALUE);
}
