Examples with QuorumServer org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer used on opensource projects

Example 1 with QuorumServer

use of org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer in project zookeeper by apache.

the class LeaderElection method lookForLeader.

/**
     * Invoked in QuorumPeer to find or elect a new leader.
     * 
     * @throws InterruptedException
     */
public Vote lookForLeader() throws InterruptedException {
    try {
        self.jmxLeaderElectionBean = new LeaderElectionBean();
        MBeanRegistry.getInstance().register(self.jmxLeaderElectionBean, self.jmxLocalPeerBean);
    } catch (Exception e) {
        LOG.warn("Failed to register with JMX", e);
        self.jmxLeaderElectionBean = null;
    }
    try {
        self.setCurrentVote(new Vote(self.getId(), self.getLastLoggedZxid()));
        // We are going to look for a leader by casting a vote for ourself
        byte[] requestBytes = new byte[4];
        ByteBuffer requestBuffer = ByteBuffer.wrap(requestBytes);
        byte[] responseBytes = new byte[28];
        ByteBuffer responseBuffer = ByteBuffer.wrap(responseBytes);
        /* The current vote for the leader. Initially me! */
        DatagramSocket s = null;
        try {
            s = new DatagramSocket();
            s.setSoTimeout(200);
        } catch (SocketException e1) {
            LOG.error("Socket exception when creating socket for leader election", e1);
            System.exit(4);
        }
        DatagramPacket requestPacket = new DatagramPacket(requestBytes, requestBytes.length);
        DatagramPacket responsePacket = new DatagramPacket(responseBytes, responseBytes.length);
        int xid = epochGen.nextInt();
        while (self.isRunning()) {
            HashMap<InetSocketAddress, Vote> votes = new HashMap<InetSocketAddress, Vote>(self.getVotingView().size());
            requestBuffer.clear();
            requestBuffer.putInt(xid);
            requestPacket.setLength(4);
            HashSet<Long> heardFrom = new HashSet<Long>();
            for (QuorumServer server : self.getVotingView().values()) {
                LOG.info("Server address: " + server.addr);
                try {
                    requestPacket.setSocketAddress(server.addr);
                } catch (IllegalArgumentException e) {
                    // in order to capture this critical detail.
                    throw new IllegalArgumentException("Unable to set socket address on packet, msg:" + e.getMessage() + " with addr:" + server.addr, e);
                }
                try {
                    s.send(requestPacket);
                    responsePacket.setLength(responseBytes.length);
                    s.receive(responsePacket);
                    if (responsePacket.getLength() != responseBytes.length) {
                        LOG.error("Got a short response: " + responsePacket.getLength());
                        continue;
                    }
                    responseBuffer.clear();
                    int recvedXid = responseBuffer.getInt();
                    if (recvedXid != xid) {
                        LOG.error("Got bad xid: expected " + xid + " got " + recvedXid);
                        continue;
                    }
                    long peerId = responseBuffer.getLong();
                    heardFrom.add(peerId);
                    //if(server.id != peerId){
                    Vote vote = new Vote(responseBuffer.getLong(), responseBuffer.getLong());
                    InetSocketAddress addr = (InetSocketAddress) responsePacket.getSocketAddress();
                    votes.put(addr, vote);
                //}
                } catch (IOException e) {
                    LOG.warn("Ignoring exception while looking for leader", e);
                // Errors are okay, since hosts may be
                // down
                }
            }
            ElectionResult result = countVotes(votes, heardFrom);
            // for a dead peer                 
            if (result.numValidVotes == 0) {
                self.setCurrentVote(new Vote(self.getId(), self.getLastLoggedZxid()));
            } else {
                if (result.winner.getId() >= 0) {
                    self.setCurrentVote(result.vote);
                    // To do: this doesn't use a quorum verifier
                    if (result.winningCount > (self.getVotingView().size() / 2)) {
                        self.setCurrentVote(result.winner);
                        s.close();
                        Vote current = self.getCurrentVote();
                        LOG.info("Found leader: my type is: " + self.getLearnerType());
                        /*
                             * We want to make sure we implement the state machine
                             * correctly. If we are a PARTICIPANT, once a leader
                             * is elected we can move either to LEADING or 
                             * FOLLOWING. However if we are an OBSERVER, it is an
                             * error to be elected as a Leader.
                             */
                        if (self.getLearnerType() == LearnerType.OBSERVER) {
                            if (current.getId() == self.getId()) {
                                // This should never happen!
                                LOG.error("OBSERVER elected as leader!");
                                Thread.sleep(100);
                            } else {
                                self.setPeerState(ServerState.OBSERVING);
                                Thread.sleep(100);
                                return current;
                            }
                        } else {
                            self.setPeerState((current.getId() == self.getId()) ? ServerState.LEADING : ServerState.FOLLOWING);
                            if (self.getPeerState() == ServerState.FOLLOWING) {
                                Thread.sleep(100);
                            }
                            return current;
                        }
                    }
                }
            }
            Thread.sleep(1000);
        }
        return null;
    } finally {
        try {
            if (self.jmxLeaderElectionBean != null) {
                MBeanRegistry.getInstance().unregister(self.jmxLeaderElectionBean);
            }
        } catch (Exception e) {
            LOG.warn("Failed to unregister with JMX", e);
        }
        self.jmxLeaderElectionBean = null;
    }
}

Example 2 with QuorumServer

use of org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer in project zookeeper by apache.

the class CnxManagerTest method testCnxManagerTimeout.

@Test
public void testCnxManagerTimeout() throws Exception {
    Random rand = new Random();
    byte b = (byte) rand.nextInt();
    int deadPort = PortAssignment.unique();
    String deadAddress = "10.1.1." + b;
    LOG.info("This is the dead address I'm trying: " + deadAddress);
    peers.put(Long.valueOf(2), new QuorumServer(2, new InetSocketAddress(deadAddress, deadPort), new InetSocketAddress(deadAddress, PortAssignment.unique()), new InetSocketAddress(deadAddress, PortAssignment.unique())));
    peerTmpdir[2] = ClientBase.createTmpDir();
    QuorumPeer peer = new QuorumPeer(peers, peerTmpdir[1], peerTmpdir[1], peerClientPort[1], 3, 1, 1000, 2, 2);
    QuorumCnxManager cnxManager = peer.createCnxnManager();
    QuorumCnxManager.Listener listener = cnxManager.listener;
    if (listener != null) {
        listener.start();
    } else {
        LOG.error("Null listener when initializing cnx manager");
    }
    long begin = Time.currentElapsedTime();
    cnxManager.toSend(2L, createMsg(ServerState.LOOKING.ordinal(), 1, -1, 1));
    long end = Time.currentElapsedTime();
    if ((end - begin) > 6000)
        Assert.fail("Waited more than necessary");
    cnxManager.halt();
    Assert.assertFalse(cnxManager.listener.isAlive());
}

Example 3 with QuorumServer

use of org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer in project rest.li by linkedin.

the class ZKQuorum method createNewPeerData.

private void createNewPeerData(int id) {
    int clientPort = ZKTestUtil.getRandomPort();
    int quorumPort = ZKTestUtil.getRandomPort() + 1000;
    int electionPort = ZKTestUtil.getRandomPort() + 1001;
    ZKPeer zkpeer = new ZKPeer(id, ZKTestUtil.createTempDir("zkdata" + id), ZKTestUtil.createTempDir("zklog" + id), HOST, clientPort, quorumPort, electionPort);
    _peers.put(id, zkpeer);
    _peersView.put(Long.valueOf(id), new QuorumServer(id, HOST, quorumPort, electionPort, LearnerType.PARTICIPANT));
    _log.info("Created peer #" + id + " with ports:" + clientPort + "/" + quorumPort + "/" + electionPort + "  peer server addr:" + _peersView.get(Long.valueOf(id)).addr + "  peer server electionAddr:" + _peersView.get(Long.valueOf(id)).electionAddr);
}

Example 4 with QuorumServer

use of org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer in project zookeeper by apache.

the class Observer method findLearnerMaster.

private QuorumServer findLearnerMaster() {
    QuorumPeer.QuorumServer prescribedLearnerMaster = nextLearnerMaster.getAndSet(null);
    if (prescribedLearnerMaster != null && self.validateLearnerMaster(Long.toString(prescribedLearnerMaster.id)) == null) {
        LOG.warn("requested next learner master {} is no longer valid", prescribedLearnerMaster);
        prescribedLearnerMaster = null;
    }
    final QuorumPeer.QuorumServer master = (prescribedLearnerMaster == null) ? self.findLearnerMaster(findLeader()) : prescribedLearnerMaster;
    currentLearnerMaster = master;
    if (master == null) {
        LOG.warn("No learner master found");
    } else {
        LOG.info("Observing new leader sid={} addr={}", master.id, master.addr);
    }
    return master;
}

Example 5 with QuorumServer

use of org.apache.zookeeper.server.quorum.QuorumPeer.QuorumServer in project zookeeper by apache.

the class Follower method followLeader.

/**
 * the main method called by the follower to follow the leader
 *
 * @throws InterruptedException
 */
void followLeader() throws InterruptedException {
    self.end_fle = Time.currentElapsedTime();
    long electionTimeTaken = self.end_fle - self.start_fle;
    self.setElectionTimeTaken(electionTimeTaken);
    ServerMetrics.getMetrics().ELECTION_TIME.add(electionTimeTaken);
    LOG.info("FOLLOWING - LEADER ELECTION TOOK - {} {}", electionTimeTaken, QuorumPeer.FLE_TIME_UNIT);
    self.start_fle = 0;
    self.end_fle = 0;
    fzk.registerJMX(new FollowerBean(this, zk), self.jmxLocalPeerBean);
    long connectionTime = 0;
    boolean completedSync = false;
    try {
        self.setZabState(QuorumPeer.ZabState.DISCOVERY);
        QuorumServer leaderServer = findLeader();
        try {
            connectToLeader(leaderServer.addr, leaderServer.hostname);
            connectionTime = System.currentTimeMillis();
            long newEpochZxid = registerWithLeader(Leader.FOLLOWERINFO);
            if (self.isReconfigStateChange()) {
                throw new Exception("learned about role change");
            }
            // check to see if the leader zxid is lower than ours
            // this should never happen but is just a safety check
            long newEpoch = ZxidUtils.getEpochFromZxid(newEpochZxid);
            if (newEpoch < self.getAcceptedEpoch()) {
                LOG.error("Proposed leader epoch " + ZxidUtils.zxidToString(newEpochZxid) + " is less than our accepted epoch " + ZxidUtils.zxidToString(self.getAcceptedEpoch()));
                throw new IOException("Error: Epoch of leader is lower");
            }
            long startTime = Time.currentElapsedTime();
            self.setLeaderAddressAndId(leaderServer.addr, leaderServer.getId());
            self.setZabState(QuorumPeer.ZabState.SYNCHRONIZATION);
            syncWithLeader(newEpochZxid);
            self.setZabState(QuorumPeer.ZabState.BROADCAST);
            completedSync = true;
            long syncTime = Time.currentElapsedTime() - startTime;
            ServerMetrics.getMetrics().FOLLOWER_SYNC_TIME.add(syncTime);
            if (self.getObserverMasterPort() > 0) {
                LOG.info("Starting ObserverMaster");
                om = new ObserverMaster(self, fzk, self.getObserverMasterPort());
                om.start();
            } else {
                om = null;
            }
            // create a reusable packet to reduce gc impact
            QuorumPacket qp = new QuorumPacket();
            while (this.isRunning()) {
                readPacket(qp);
                processPacket(qp);
            }
        } catch (Exception e) {
            LOG.warn("Exception when following the leader", e);
            closeSocket();
            // clear pending revalidations
            pendingRevalidations.clear();
        }
    } finally {
        if (om != null) {
            om.stop();
        }
        zk.unregisterJMX(this);
        if (connectionTime != 0) {
            long connectionDuration = System.currentTimeMillis() - connectionTime;
            LOG.info("Disconnected from leader (with address: {}). Was connected for {}ms. Sync state: {}", leaderAddr, connectionDuration, completedSync);
            messageTracker.dumpToLog(leaderAddr.toString());
        }
    }
}