Constructor Detail

• MasterAddressTracker

  public MasterAddressTracker(ZooKeeperWatcher watcher,
                      Abortable abortable)

  Construct a master address listener with the specified zookeeper reference.

  This constructor does not trigger any actions, you must call methods explicitly. Normally you will just want to execute ZooKeeperNodeTracker.start() to begin tracking of the master address.

  Parameters:

  watcher - zk reference and watcher

  abortable - abortable in case of fatal error

Method Detail

• getMasterAddress

  public ServerName getMasterAddress()

  Get the address of the current master if one is available. Returns null if no current master.

  Returns:

  Server name or null if timed out.

• getMasterInfoPort

  public int getMasterInfoPort()

  Get the info port of the current master of one is available. Return 0 if no current master or zookeeper is unavailable

  Returns:

  info port or 0 if timed out

• getBackupMasterInfoPort

  public int getBackupMasterInfoPort(ServerName sn)

  Get the info port of the backup master if it is available. Return 0 if no backup master or zookeeper is unavailable

  Parameters:

  sn - server name of backup master

  Returns:

  info port or 0 if timed out or exceptions

• getMasterAddress

  public ServerName getMasterAddress(boolean refresh)

  Get the address of the current master if one is available. Returns null if no current master. If refresh is set, try to load the data from ZK again, otherwise, cached data will be used.

  Parameters:

  refresh - whether to refresh the data by calling ZK directly.

  Returns:

  Server name or null if timed out.

• getMasterAddress

  public static ServerName getMasterAddress(ZooKeeperWatcher zkw)
                                     throws org.apache.zookeeper.KeeperException,
                                            IOException

  Get master address. Use this instead of getMasterAddress() if you do not have an instance of this tracker in your context.

  Parameters:

  zkw - ZooKeeperWatcher to use

  Returns:

  ServerName stored in the the master address znode or null if no znode present.

  Throws:

  org.apache.zookeeper.KeeperException

  IOException

• getMasterInfoPort

  public static int getMasterInfoPort(ZooKeeperWatcher zkw)
                               throws org.apache.zookeeper.KeeperException,
                                      IOException

  Get master info port. Use this instead of getMasterInfoPort() if you do not have an instance of this tracker in your context.

  Parameters:

  zkw - ZooKeeperWatcher to use

  Returns:

  master info port in the the master address znode or null if no znode present. // TODO can't return null for 'int' return type. non-static verison returns 0

  Throws:

  org.apache.zookeeper.KeeperException

  IOException

• setMasterAddress

  public static boolean setMasterAddress(ZooKeeperWatcher zkw,
                         String znode,
                         ServerName master,
                         int infoPort)
                                  throws org.apache.zookeeper.KeeperException

  Set master address into the master znode or into the backup subdirectory of backup masters; switch off the passed in znode path.

  Parameters:

  zkw - The ZooKeeperWatcher to use.

  znode - Where to create the znode; could be at the top level or it could be under backup masters

  master - ServerName of the current master must not be null.

  Returns:

  true if node created, false if not; a watch is set in both cases

  Throws:

  org.apache.zookeeper.KeeperException

• hasMaster

  public boolean hasMaster()

  Check if there is a master available.

  Returns:

  true if there is a master set, false if not.

• parse

  public static org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.Master parse(byte[] data)
                                                                                 throws DeserializationException

  Parameters:

  data - zookeeper data. may be null

  Returns:

  pb object of master, null if no active master

  Throws:

  DeserializationException

• deleteIfEquals

  public static boolean deleteIfEquals(ZooKeeperWatcher zkw,
                       String content)

  delete the master znode if its content is same as the parameter

  Parameters:

  zkw - must not be null

  content - must not be null