Package org.apache.zookeeper.server.quorum

Class QuorumPeer

  • All Implemented Interfaces:
    java.lang.Runnable, QuorumStats.Provider
    public class QuorumPeer
extends ZooKeeperThread
implements QuorumStats.Provider
    This class manages the quorum protocol. There are three states this server can be in:
    1. Leader election - each server will elect a leader (proposing itself as a leader initially).
    2. Follower - the server will synchronize with the leader and replicate any transactions.
    3. Leader - the server will process requests and forward them to followers. A majority of followers must log the request before it can be accepted.
    This class will setup a datagram socket that will always respond with its view of the current leader. The response will take the form of: 
     int xid;

 long myid;

 long leader_id;

 long leader_zxid;
    The request for the current leader will consist solely of an xid: int xid;

    • Field Detail

      • start_fle

        public long start_fle

      • end_fle

        public long end_fle

      • quorumPeers

        protected java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers
        The servers that make up the cluster

      • tickTime

        protected int tickTime
        The number of milliseconds of each tick

      • minSessionTimeout

        protected int minSessionTimeout
        Minimum number of milliseconds to allow for session timeout. A value of -1 indicates unset, use default.

      • maxSessionTimeout

        protected int maxSessionTimeout
        Maximum number of milliseconds to allow for session timeout. A value of -1 indicates unset, use default.

      • initLimit

        protected int initLimit
        The number of ticks that the initial synchronization phase can take

      • syncLimit

        protected int syncLimit
        The number of ticks that can pass between sending a request and getting an acknowledgment

      • syncEnabled

        protected boolean syncEnabled
        Enables/Disables sync request processor. This option is enabled by default and is to be used with observers.

      • tick

        protected java.util.concurrent.atomic.AtomicInteger tick
        The current tick

      • quorumListenOnAllIPs

        protected boolean quorumListenOnAllIPs
        Whether or not to listen on all IPs for the two quorum ports (broadcast and fast leader election).

      • quorumSaslEnableAuth

        protected boolean quorumSaslEnableAuth
        Enable/Disables quorum authentication using sasl. Defaulting to false.

      • quorumServerSaslAuthRequired

        protected boolean quorumServerSaslAuthRequired
        If this is false, quorum peer server will accept another quorum peer client connection even if the authentication did not succeed. This can be used while upgrading ZooKeeper server. Defaulting to false (required).

      • quorumLearnerSaslAuthRequired

        protected boolean quorumLearnerSaslAuthRequired
        If this is false, quorum peer learner will talk to quorum peer server without authentication. This can be used while upgrading ZooKeeper server. Defaulting to false (required).

      • quorumServicePrincipal

        protected java.lang.String quorumServicePrincipal
        Kerberos quorum service principal. Defaulting to 'zkquorum/localhost'.

      • quorumLearnerLoginContext

        protected java.lang.String quorumLearnerLoginContext
        Quorum learner login context name in jaas-conf file to read the kerberos security details. Defaulting to 'QuorumLearner'.

      • quorumServerLoginContext

        protected java.lang.String quorumServerLoginContext
        Quorum server login context name in jaas-conf file to read the kerberos security details. Defaulting to 'QuorumServer'.

      • quorumCnxnThreadsSize

        protected int quorumCnxnThreadsSize
        The maximum number of threads to allow in the connectionExecutors thread pool which will be used to initiate quorum server connections.

      • leader

        public Leader leader

      • SYNC_ENABLED

        public static final java.lang.String SYNC_ENABLED
        The syncEnabled can also be set via a system property.
        See Also:
        Constant Field Values

      • CURRENT_EPOCH_FILENAME

        public static final java.lang.String CURRENT_EPOCH_FILENAME
        See Also:
        Constant Field Values

      • ACCEPTED_EPOCH_FILENAME

        public static final java.lang.String ACCEPTED_EPOCH_FILENAME
        See Also:
        Constant Field Values

      • UPDATING_EPOCH_FILENAME

        public static final java.lang.String UPDATING_EPOCH_FILENAME
        See Also:
        Constant Field Values

    • Constructor Detail

      • QuorumPeer

        protected QuorumPeer()
              throws javax.security.sasl.SaslException
        Throws:
        javax.security.sasl.SaslException

      • QuorumPeer

        public QuorumPeer​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers,
                  java.io.File dataDir,
                  java.io.File dataLogDir,
                  int electionType,
                  long myid,
                  int tickTime,
                  int initLimit,
                  int syncLimit,
                  ServerCnxnFactory cnxnFactory)
           throws java.io.IOException
        For backward compatibility purposes, we instantiate QuorumMaj by default.
        Throws:
        java.io.IOException

      • QuorumPeer

        public QuorumPeer​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers,
                  java.io.File dataDir,
                  java.io.File dataLogDir,
                  int electionType,
                  long myid,
                  int tickTime,
                  int initLimit,
                  int syncLimit,
                  boolean quorumListenOnAllIPs,
                  ServerCnxnFactory cnxnFactory,
                  QuorumVerifier quorumConfig)
           throws java.io.IOException
        Throws:
        java.io.IOException

      • QuorumPeer

        public QuorumPeer​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers,
                  java.io.File snapDir,
                  java.io.File logDir,
                  int clientPort,
                  int electionAlg,
                  long myid,
                  int tickTime,
                  int initLimit,
                  int syncLimit)
           throws java.io.IOException
        This constructor is only used by the existing unit test code. It defaults to FileLogProvider persistence provider.
        Throws:
        java.io.IOException

      • QuorumPeer

        public QuorumPeer​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers,
                  java.io.File snapDir,
                  java.io.File logDir,
                  int clientPort,
                  int electionAlg,
                  long myid,
                  int tickTime,
                  int initLimit,
                  int syncLimit,
                  QuorumVerifier quorumConfig)
           throws java.io.IOException
        This constructor is only used by the existing unit test code. It defaults to FileLogProvider persistence provider.
        Throws:
        java.io.IOException

    • Method Detail

      • setLearnerType

        public void setLearnerType​(QuorumPeer.LearnerType p)
        Sets the LearnerType both in the QuorumPeer and in the peerMap

      • getQuorumSize

        public int getQuorumSize()

      • getId

        public long getId()
        get the id of this quorum peer.
        Overrides:
        getId in class java.lang.Thread

      • getCurrentVote

        public Vote getCurrentVote()

      • setCurrentVote

        public void setCurrentVote​(Vote v)

      • getQuorumAddress

        public java.net.InetSocketAddress getQuorumAddress()

      • testingQuorumPeer

        public static QuorumPeer testingQuorumPeer()
                                    throws javax.security.sasl.SaslException
        Throws:
        javax.security.sasl.SaslException

      • initialize

        public void initialize()
                throws javax.security.sasl.SaslException
        Throws:
        javax.security.sasl.SaslException

      • start

        public void start()
        Overrides:
        start in class java.lang.Thread

      • stopLeaderElection

        public void stopLeaderElection()

      • startLeaderElection

        public void startLeaderElection()

      • countParticipants

        protected static int countParticipants​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> peers)
        Count the number of nodes in the map that could be followers.
        Parameters:
        peers -
        Returns:
        The number of followers in the map

      • getLastLoggedZxid

        public long getLastLoggedZxid()
        returns the highest zxid that this host has seen
        Returns:
        the highest zxid for this host

      • makeFollower

        protected Follower makeFollower​(FileTxnSnapLog logFactory)
                         throws java.io.IOException
        Throws:
        java.io.IOException

      • makeLeader

        protected Leader makeLeader​(FileTxnSnapLog logFactory)
                     throws java.io.IOException
        Throws:
        java.io.IOException

      • makeObserver

        protected Observer makeObserver​(FileTxnSnapLog logFactory)
                         throws java.io.IOException
        Throws:
        java.io.IOException

      • createElectionAlgorithm

        protected Election createElectionAlgorithm​(int electionAlgorithm)

      • makeLEStrategy

        protected Election makeLEStrategy()

      • setLeader

        protected void setLeader​(Leader newLeader)

      • setFollower

        protected void setFollower​(Follower newFollower)

      • setObserver

        protected void setObserver​(Observer newObserver)

      • run

        public void run()
        Specified by:
        run in interface java.lang.Runnable
        Overrides:
        run in class java.lang.Thread

      • shutdown

        public void shutdown()

      • getView

        public java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> getView()
        A 'view' is a node's current opinion of the membership of the entire ensemble.

      • getVotingView

        public java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> getVotingView()
        Observers are not contained in this view, only nodes with PeerType=PARTICIPANT.

      • getObservingView

        public java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> getObservingView()
        Returns only observers, no followers.

      • viewContains

        public boolean viewContains​(java.lang.Long sid)
        Check if a node is in the current view. With static membership, the result of this check will never change; only when dynamic membership is introduced will this be more useful.

      • getMyid

        public long getMyid()
        get the id of this quorum peer.

      • setMyid

        public void setMyid​(long myid)
        set the id of this quorum peer.

      • getTickTime

        public int getTickTime()
        Get the number of milliseconds of each tick

      • setTickTime

        public void setTickTime​(int tickTime)
        Set the number of milliseconds of each tick

      • getMaxClientCnxnsPerHost

        public int getMaxClientCnxnsPerHost()
        Maximum number of connections allowed from particular host (ip)

      • getMinSessionTimeout

        public int getMinSessionTimeout()
        minimum session timeout in milliseconds

      • setMinSessionTimeout

        public void setMinSessionTimeout​(int min)
        minimum session timeout in milliseconds

      • getMaxSessionTimeout

        public int getMaxSessionTimeout()
        maximum session timeout in milliseconds

      • setMaxSessionTimeout

        public void setMaxSessionTimeout​(int max)
        minimum session timeout in milliseconds

      • getInitLimit

        public int getInitLimit()
        Get the number of ticks that the initial synchronization phase can take

      • setInitLimit

        public void setInitLimit​(int initLimit)
        Set the number of ticks that the initial synchronization phase can take

      • getTick

        public int getTick()
        Get the current tick

      • getQuorumVerifier

        public QuorumVerifier getQuorumVerifier()
        Return QuorumVerifier object

      • setQuorumVerifier

        public void setQuorumVerifier​(QuorumVerifier quorumConfig)

      • getElectionAlg

        public Election getElectionAlg()
        Get an instance of LeaderElection

      • getSyncLimit

        public int getSyncLimit()
        Get the synclimit

      • setSyncLimit

        public void setSyncLimit​(int syncLimit)
        Set the synclimit

      • getSyncEnabled

        public boolean getSyncEnabled()
        Return syncEnabled.
        Returns:

      • setSyncEnabled

        public void setSyncEnabled​(boolean syncEnabled)
        Set syncEnabled.
        Parameters:
        syncEnabled -

      • getElectionType

        public int getElectionType()
        Gets the election type

      • setElectionType

        public void setElectionType​(int electionType)
        Sets the election type

      • getQuorumListenOnAllIPs

        public boolean getQuorumListenOnAllIPs()

      • setQuorumListenOnAllIPs

        public void setQuorumListenOnAllIPs​(boolean quorumListenOnAllIPs)

      • setQuorumPeers

        public void setQuorumPeers​(java.util.Map<java.lang.Long,​QuorumPeer.QuorumServer> quorumPeers)

      • getClientPort

        public int getClientPort()

      • setClientPortAddress

        public void setClientPortAddress​(java.net.InetSocketAddress addr)

      • setTxnFactory

        public void setTxnFactory​(FileTxnSnapLog factory)

      • setZKDatabase

        public void setZKDatabase​(ZKDatabase database)
        set zk database for this node
        Parameters:
        database -

      • setRunning

        public void setRunning​(boolean running)

      • isRunning

        public boolean isRunning()

      • getQuorumCnxManager

        public QuorumCnxManager getQuorumCnxManager()
        get reference to QuorumCnxManager

      • getCurrentEpoch

        public long getCurrentEpoch()
                     throws java.io.IOException
        Throws:
        java.io.IOException

      • getAcceptedEpoch

        public long getAcceptedEpoch()
                      throws java.io.IOException
        Throws:
        java.io.IOException

      • setCurrentEpoch

        public void setCurrentEpoch​(long e)
                     throws java.io.IOException
        Throws:
        java.io.IOException

      • setAcceptedEpoch

        public void setAcceptedEpoch​(long e)
                      throws java.io.IOException
        Throws:
        java.io.IOException

      • updateElectionVote

        protected void updateElectionVote​(long newEpoch)
        Updates leader election info to avoid inconsistencies when a new server tries to join the ensemble. See ZOOKEEPER-1732 for more info.

      • hasAuthInitialized

        public boolean hasAuthInitialized()