org.apache.hadoop.hbase.procedure2

Class ProcedureInMemoryChore<TEnvironment>

java.lang.Object

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

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

All Implemented Interfaces:

Comparable<Procedure<TEnvironment>>

Direct Known Subclasses:

AssignmentManager.RegionInTransitionChore, CompletedProcedureCleaner

@InterfaceAudience.Private
 @InterfaceStability.Evolving
public abstract class ProcedureInMemoryChore<TEnvironment>
extends Procedure<TEnvironment>

Special procedure used as a chore. Instead of bringing the Chore class in (dependencies reason), we reuse the executor timeout thread for this special case. The assumption is that procedure is used as hook to dispatch other procedures or trigger some cleanups. It does not store state in the ProcedureStore. this is just for in-memory chore executions.

Nested Class Summary

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

Procedure.LockState

Field Summary

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

NO_PROC_ID, NO_TIMEOUT

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ProcedureInMemoryChore(int timeoutMsec)

Method Summary

Modifier and Type	Method and Description
protected boolean	abort(TEnvironment env) The abort() call is asynchronous and each procedure must decide how to deal with it, if they want to be abortable.
protected void	deserializeStateData(ProcedureStateSerializer serializer) Called on store load to allow the user to decode the previously serialized state.
protected Procedure<TEnvironment>[]	execute(TEnvironment env) The main code of the procedure.
protected abstract void	periodicExecute(TEnvironment env)
protected void	rollback(TEnvironment env) The code to undo what was done by the execute() code.
protected void	serializeStateData(ProcedureStateSerializer serializer) The user-level code of the procedure may have some state to persist (e.g.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ProcedureInMemoryChore

protected ProcedureInMemoryChore(int timeoutMsec)

Method Detail

periodicExecute

protected abstract void periodicExecute(TEnvironment env)

execute

protected Procedure<TEnvironment>[] execute(TEnvironment env)

Description copied from class: Procedure

The main code of the procedure. It must be idempotent since execute() may be called multiple times in case of machine failure in the middle of the execution.

Specified by:

execute in class Procedure<TEnvironment>

Parameters:

env - the environment passed to the ProcedureExecutor

Returns:

a set of sub-procedures to run or ourselves if there is more work to do or null if the procedure is done.

rollback

protected void rollback(TEnvironment env)

Description copied from class: Procedure

The code to undo what was done by the execute() code. It is called when the procedure or one of the sub-procedures failed or an abort was requested. It should cleanup all the resources created by the execute() call. The implementation must be idempotent since rollback() may be called multiple time in case of machine failure in the middle of the execution.

Specified by:

rollback in class Procedure<TEnvironment>

Parameters:

env - the environment passed to the ProcedureExecutor

abort

protected boolean abort(TEnvironment 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.

Specified by:

abort in class Procedure<TEnvironment>

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.

Specified by:

serializeStateData in class Procedure<TEnvironment>

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.

Specified by:

deserializeStateData in class Procedure<TEnvironment>

Parameters:

serializer - contains the serialized state

Throws:

IOException