org.apache.hadoop.hbase.procedure

Class ZKProcedureCoordinator

java.lang.Object

org.apache.hadoop.hbase.procedure.ZKProcedureCoordinator

All Implemented Interfaces:

Closeable, AutoCloseable, ProcedureCoordinatorRpcs

@InterfaceAudience.Private
public class ZKProcedureCoordinator
extends Object
implements ProcedureCoordinatorRpcs

ZooKeeper based ProcedureCoordinatorRpcs for a ProcedureCoordinator

Field Summary

Fields

Modifier and Type	Field and Description
protected ProcedureCoordinator	coordinator
(package private) String	coordName
private static org.slf4j.Logger	LOG
(package private) String	procedureType
(package private) ZKWatcher	watcher
private ZKProcedureUtil	zkProc

Constructor Summary

Constructors

Constructor and Description
ZKProcedureCoordinator(ZKWatcher watcher, String procedureClass, String coordName)

Method Summary

Modifier and Type	Method and Description
protected void	abort(String abortNode) Receive a notification and propagate it to the local coordinator
void	close()
(package private) ZKProcedureUtil	getZkProcedureUtil() Used in testing
void	resetMembers(Procedure proc) Delete znodes that are no longer in use.
void	sendAbortToMembers(Procedure proc, ForeignException ee) This is the abort message being sent by the coordinator to member TODO this code isn't actually used but can be used to issue a cancellation from the coordinator.
void	sendGlobalBarrierAcquire(Procedure proc, byte[] info, List<String> nodeNames) The "acquire" phase.
void	sendGlobalBarrierReached(Procedure proc, List<String> nodeNames) Notify members that all members have acquired their parts of the barrier and that they can now execute under the global barrier.
boolean	start(ProcedureCoordinator coordinator) Start monitoring znodes in ZK - subclass hook to start monitoring znodes they are about.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

private static final org.slf4j.Logger LOG

zkProc

private ZKProcedureUtil zkProc

coordinator

protected ProcedureCoordinator coordinator

watcher

ZKWatcher watcher

procedureType

String procedureType

coordName

String coordName

Constructor Detail

ZKProcedureCoordinator

public ZKProcedureCoordinator(ZKWatcher watcher,
                              String procedureClass,
                              String coordName)

Parameters:

watcher - zookeeper watcher. Owned by this and closed via close()

procedureClass - procedure type name is a category for when there are multiple kinds of procedures.-- this becomes a znode so be aware of the naming restrictions

coordName - name of the node running the coordinator

Throws:

org.apache.zookeeper.KeeperException - if an unexpected zk error occurs

Method Detail

sendGlobalBarrierAcquire

public final void sendGlobalBarrierAcquire(Procedure proc,
                                           byte[] info,
                                           List<String> nodeNames)
                                    throws IOException,
                                           IllegalArgumentException

The "acquire" phase. The coordinator creates a new procType/acquired/ znode dir. If znodes appear, first acquire to relevant listener or sets watch waiting for notification of the acquire node

Specified by:

sendGlobalBarrierAcquire in interface ProcedureCoordinatorRpcs

Parameters:

proc - the Procedure

info - data to be stored in the acquire node

nodeNames - children of the acquire phase

Throws:

IOException - if any failure occurs.

IllegalArgumentException - if the procedure was already marked as failed

sendGlobalBarrierReached

public void sendGlobalBarrierReached(Procedure proc,
                                     List<String> nodeNames)
                              throws IOException

Description copied from interface: ProcedureCoordinatorRpcs

Notify members that all members have acquired their parts of the barrier and that they can now execute under the global barrier. Must come after calling ProcedureCoordinatorRpcs.sendGlobalBarrierAcquire(Procedure, byte[], List)

Specified by:

sendGlobalBarrierReached in interface ProcedureCoordinatorRpcs

Parameters:

proc - name of the procedure to start

nodeNames - members to tell we have reached in-barrier phase

Throws:

IOException - if we can't reach the remote notification mechanism

resetMembers

public final void resetMembers(Procedure proc)
                        throws IOException

Delete znodes that are no longer in use.

Specified by:

resetMembers in interface ProcedureCoordinatorRpcs

Parameters:

proc - name of the procedure to reset

Throws:

IOException - if the remote notification mechanism cannot be reached

start

public final boolean start(ProcedureCoordinator coordinator)

Start monitoring znodes in ZK - subclass hook to start monitoring znodes they are about.

Specified by:

start in interface ProcedureCoordinatorRpcs

Returns:

true if succeed, false if encountered initialization errors.

sendAbortToMembers

public final void sendAbortToMembers(Procedure proc,
                                     ForeignException ee)

This is the abort message being sent by the coordinator to member TODO this code isn't actually used but can be used to issue a cancellation from the coordinator.

Specified by:

sendAbortToMembers in interface ProcedureCoordinatorRpcs

Parameters:

proc - name of the procedure that was aborted

ee - the reason why the procedure needs to be aborted

abort

protected void abort(String abortNode)

Receive a notification and propagate it to the local coordinator

Parameters:

abortNode - full znode path to the failed procedure information

close

public final void close()
                 throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

getZkProcedureUtil

final ZKProcedureUtil getZkProcedureUtil()

Used in testing