org.apache.hadoop.hbase.master.assignment

Class MergeTableRegionsProcedure

java.lang.Object

org.apache.hadoop.hbase.procedure2.Procedure<TEnvironment>

org.apache.hadoop.hbase.procedure2.StateMachineProcedure<MasterProcedureEnv,TState>

org.apache.hadoop.hbase.master.procedure.AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

org.apache.hadoop.hbase.master.assignment.MergeTableRegionsProcedure

All Implemented Interfaces:

Comparable<Procedure<MasterProcedureEnv>>, TableProcedureInterface

@InterfaceAudience.Private
public class MergeTableRegionsProcedure
extends AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

The procedure to Merge a region in a table. This procedure takes an exclusive table lock since it is working over multiple regions. It holds the lock for the life of the procedure.

Throws exception on construction if determines context hostile to merge (cluster going down or master is shutting down or table is disabled).

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.procedure2.StateMachineProcedure

StateMachineProcedure.Flow

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.procedure2.Procedure

Procedure.LockState

Nested classes/interfaces inherited from interface org.apache.hadoop.hbase.master.procedure.TableProcedureInterface

TableProcedureInterface.TableOperationType

Field Summary

Fields inherited from class org.apache.hadoop.hbase.procedure2.StateMachineProcedure

stateCount

Fields inherited from class org.apache.hadoop.hbase.procedure2.Procedure

NO_PROC_ID, NO_TIMEOUT

Constructor Summary

Constructors

Constructor and Description
MergeTableRegionsProcedure()
MergeTableRegionsProcedure(MasterProcedureEnv env, RegionInfo[] regionsToMerge, boolean forcible)
MergeTableRegionsProcedure(MasterProcedureEnv env, RegionInfo regionToMergeA, RegionInfo regionToMergeB)
MergeTableRegionsProcedure(MasterProcedureEnv env, RegionInfo regionToMergeA, RegionInfo regionToMergeB, boolean forcible)

Method Summary

Modifier and Type	Method and Description
protected boolean	abort(MasterProcedureEnv env) The abort() call is asynchronous and each procedure must decide how to deal with it, if they want to be abortable.
protected Procedure.LockState	acquireLock(MasterProcedureEnv env) The user should override this method if they need a lock on an Entity.
protected void	deserializeStateData(ProcedureStateSerializer serializer) Called on store load to allow the user to decode the previously serialized state.
protected StateMachineProcedure.Flow	executeFromState(MasterProcedureEnv env, MasterProcedureProtos.MergeTableRegionsState state) called to perform a single step of the specified 'state' of the procedure
protected MasterProcedureProtos.MergeTableRegionsState	getInitialState() Return the initial state object that will be used for the first call to executeFromState().
RegionInfo	getMergedRegion()
protected ProcedureMetrics	getProcedureMetrics(MasterProcedureEnv env) Override this method to provide procedure specific counters for submitted count, failed count and time histogram.
protected MasterProcedureProtos.MergeTableRegionsState	getState(int stateId) Convert an ordinal (or state id) to an Enum (or more descriptive) state object.
protected int	getStateId(MasterProcedureProtos.MergeTableRegionsState state) Convert the Enum (or more descriptive) state object to an ordinal (or state id).
TableName	getTableName()
TableProcedureInterface.TableOperationType	getTableOperationType() Given an operation type we can take decisions about what to do with pending operations.
protected boolean	holdLock(MasterProcedureEnv env) Used to keep the procedure lock even when the procedure is yielding or suspended.
protected boolean	isRollbackSupported(MasterProcedureProtos.MergeTableRegionsState state) Used by the default implementation of abort() to know if the current state can be aborted and rollback can be triggered.
protected void	releaseLock(MasterProcedureEnv env) The user should override this method, and release lock if necessary.
protected void	rollbackState(MasterProcedureEnv env, MasterProcedureProtos.MergeTableRegionsState state) To rollback MergeTableRegionsProcedure, two AssignProcedures are asynchronously submitted for each region to be merged (rollback doesn't wait on the completion of the AssignProcedures) .
protected void	serializeStateData(ProcedureStateSerializer serializer) The user-level code of the procedure may have some state to persist (e.g.
void	setRegionStateToMerging(MasterProcedureEnv env) Set the region states to MERGING state
void	toStringClassDetails(StringBuilder sb) Extend the toString() information with the procedure details e.g.

Methods inherited from class org.apache.hadoop.hbase.master.procedure.AbstractStateMachineTableProcedure

checkOnline, checkTableModifiable, getUser, getWALRegionDir, preflightChecks, releaseSyncLatch, setUser, waitInitialized

Methods inherited from class org.apache.hadoop.hbase.procedure2.StateMachineProcedure

addChildProcedure, execute, failIfAborted, getCurrentState, getCurrentStateId, getCycles, isEofState, isYieldAfterExecutionStep, isYieldBeforeExecuteFromState, rollback, setNextState, toStringState

Methods inherited from class org.apache.hadoop.hbase.procedure2.Procedure

addStackIndex, afterReplay, beforeReplay, bypass, compareTo, completionCleanup, doExecute, doRollback, elapsedTime, getChildrenLatch, getException, getLastUpdate, getNonceKey, getOwner, getParentProcId, getProcId, getProcIdHashCode, getProcName, getResult, getRootProcedureId, getRootProcId, getStackIndexes, getState, getSubmittedTime, getTimeout, getTimeoutTimestamp, hasChildren, hasException, hasLock, hasOwner, hasParent, hasTimeout, haveSameParent, incChildrenLatch, isBypass, isFailed, isFinished, isInitializing, isLockedWhenLoading, isRunnable, isSuccess, isWaiting, removeStackIndex, setAbortFailure, setChildrenLatch, setFailure, setFailure, setLastUpdate, setNonceKey, setOwner, setOwner, setParentProcId, setProcId, setResult, setRootProcId, setStackIndexes, setState, setSubmittedTime, setTimeout, setTimeoutFailure, shouldWaitClientAck, skipPersistence, toString, toStringClass, toStringDetails, toStringSimpleSB, updateMetricsOnFinish, updateMetricsOnSubmit, updateTimestamp, wasExecuted

Methods inherited from class java.lang.Object

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

Constructor Detail

MergeTableRegionsProcedure

public MergeTableRegionsProcedure()

MergeTableRegionsProcedure

public MergeTableRegionsProcedure(MasterProcedureEnv env,
                                  RegionInfo regionToMergeA,
                                  RegionInfo regionToMergeB)
                           throws IOException

Throws:

IOException

MergeTableRegionsProcedure

public MergeTableRegionsProcedure(MasterProcedureEnv env,
                                  RegionInfo regionToMergeA,
                                  RegionInfo regionToMergeB,
                                  boolean forcible)
                           throws IOException

Throws:

IOException

MergeTableRegionsProcedure

public MergeTableRegionsProcedure(MasterProcedureEnv env,
                                  RegionInfo[] regionsToMerge,
                                  boolean forcible)
                           throws IOException

Throws:

IOException

Method Detail

executeFromState

protected StateMachineProcedure.Flow executeFromState(MasterProcedureEnv env,
                                                      MasterProcedureProtos.MergeTableRegionsState state)

Description copied from class: StateMachineProcedure

called to perform a single step of the specified 'state' of the procedure

Specified by:

executeFromState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

state - state to execute

Returns:

Flow.NO_MORE_STATE if the procedure is completed, Flow.HAS_MORE_STATE if there is another step.

rollbackState

protected void rollbackState(MasterProcedureEnv env,
                             MasterProcedureProtos.MergeTableRegionsState state)
                      throws IOException

To rollback MergeTableRegionsProcedure, two AssignProcedures are asynchronously submitted for each region to be merged (rollback doesn't wait on the completion of the AssignProcedures) . This can be improved by changing rollback() to support sub-procedures. See HBASE-19851 for details.

Specified by:

rollbackState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

state - state to rollback

Throws:

IOException - temporary failure, the rollback will retry later

isRollbackSupported

protected boolean isRollbackSupported(MasterProcedureProtos.MergeTableRegionsState state)

Description copied from class: StateMachineProcedure

Used by the default implementation of abort() to know if the current state can be aborted and rollback can be triggered.

Overrides:

isRollbackSupported in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

getState

protected MasterProcedureProtos.MergeTableRegionsState getState(int stateId)

Description copied from class: StateMachineProcedure

Convert an ordinal (or state id) to an Enum (or more descriptive) state object.

Specified by:

getState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

Parameters:

stateId - the ordinal() of the state enum (or state id)

Returns:

the state enum object

getStateId

protected int getStateId(MasterProcedureProtos.MergeTableRegionsState state)

Description copied from class: StateMachineProcedure

Convert the Enum (or more descriptive) state object to an ordinal (or state id).

Specified by:

getStateId in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

Parameters:

state - the state enum object

Returns:

stateId the ordinal() of the state enum (or state id)

getInitialState

protected MasterProcedureProtos.MergeTableRegionsState getInitialState()

Description copied from class: StateMachineProcedure

Return the initial state object that will be used for the first call to executeFromState().

Specified by:

getInitialState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

Returns:

the initial state enum object

serializeStateData

protected void serializeStateData(ProcedureStateSerializer serializer)
                           throws IOException

Description copied from class: Procedure

The user-level code of the procedure may have some state to persist (e.g. input arguments or current position in the processing state) to be able to resume on failure.

Overrides:

serializeStateData in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

Parameters:

serializer - stores the serializable state

Throws:

IOException

deserializeStateData

protected void deserializeStateData(ProcedureStateSerializer serializer)
                             throws IOException

Description copied from class: Procedure

Called on store load to allow the user to decode the previously serialized state.

Overrides:

deserializeStateData in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>

Parameters:

serializer - contains the serialized state

Throws:

IOException

toStringClassDetails

public void toStringClassDetails(StringBuilder sb)

Description copied from class: Procedure

Extend the toString() information with the procedure details e.g. className and parameters

Overrides:

toStringClassDetails in class AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

Parameters:

sb - the string builder to use to append the proc specific information

acquireLock

protected Procedure.LockState acquireLock(MasterProcedureEnv env)

Description copied from class: Procedure

The user should override this method if they need a lock on an Entity. A lock can be anything, and it is up to the implementor. The Procedure Framework will call this method just before it invokes Procedure.execute(Object). It calls Procedure.releaseLock(Object) after the call to execute.

If you need to hold the lock for the life of the Procedure -- i.e. you do not want any other Procedure interfering while this Procedure is running, see Procedure.holdLock(Object).

Example: in our Master we can execute request in parallel for different tables. We can create t1 and create t2 and these creates can be executed at the same time. Anything else on t1/t2 is queued waiting that specific table create to happen.

There are 3 LockState:

• LOCK_ACQUIRED should be returned when the proc has the lock and the proc is ready to execute.
• LOCK_YIELD_WAIT should be returned when the proc has not the lock and the framework should take care of readding the procedure back to the runnable set for retry
• LOCK_EVENT_WAIT should be returned when the proc has not the lock and someone will take care of readding the procedure back to the runnable set when the lock is available.

Overrides:

acquireLock in class AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

Returns:

the lock state as described above.

releaseLock

protected void releaseLock(MasterProcedureEnv env)

Description copied from class: Procedure

The user should override this method, and release lock if necessary.

Overrides:

releaseLock in class AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

holdLock

protected boolean holdLock(MasterProcedureEnv env)

Description copied from class: Procedure

Used to keep the procedure lock even when the procedure is yielding or suspended.

Overrides:

holdLock in class Procedure<MasterProcedureEnv>

Returns:

true if the procedure should hold on the lock until completionCleanup()

getTableName

public TableName getTableName()

Specified by:

getTableName in interface TableProcedureInterface

Specified by:

getTableName in class AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

Returns:

the name of the table the procedure is operating on

getTableOperationType

public TableProcedureInterface.TableOperationType getTableOperationType()

Description copied from interface: TableProcedureInterface

Given an operation type we can take decisions about what to do with pending operations. e.g. if we get a delete and we have some table operation pending (e.g. add column) we can abort those operations.

Specified by:

getTableOperationType in interface TableProcedureInterface

Specified by:

getTableOperationType in class AbstractStateMachineTableProcedure<MasterProcedureProtos.MergeTableRegionsState>

Returns:

the operation type that the procedure is executing.

getProcedureMetrics

protected ProcedureMetrics getProcedureMetrics(MasterProcedureEnv env)

Description copied from class: Procedure

Override this method to provide procedure specific counters for submitted count, failed count and time histogram.

Overrides:

getProcedureMetrics in class Procedure<MasterProcedureEnv>

Parameters:

env - The environment passed to the procedure executor

Returns:

Container object for procedure related metric

setRegionStateToMerging

public void setRegionStateToMerging(MasterProcedureEnv env)

Set the region states to MERGING state

Parameters:

env - MasterProcedureEnv

getMergedRegion

public RegionInfo getMergedRegion()

Returns:

The merged region. Maybe be null if called to early or we failed.

abort

protected boolean abort(MasterProcedureEnv env)

Description copied from class: Procedure

The abort() call is asynchronous and each procedure must decide how to deal with it, if they want to be abortable. The simplest implementation is to have an AtomicBoolean set in the abort() method and then the execute() will check if the abort flag is set or not. abort() may be called multiple times from the client, so the implementation must be idempotent.

NOTE: abort() is not like Thread.interrupt(). It is just a notification that allows the procedure implementor abort.

Overrides:

abort in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.MergeTableRegionsState>