org.apache.hadoop.hbase.master.procedure

Class AbstractStateMachineNamespaceProcedure<TState>

java.lang.Object

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

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

org.apache.hadoop.hbase.master.procedure.AbstractStateMachineNamespaceProcedure<TState>

All Implemented Interfaces:

Comparable<Procedure<MasterProcedureEnv>>, TableProcedureInterface

Direct Known Subclasses:

CreateNamespaceProcedure, DeleteNamespaceProcedure, ModifyNamespaceProcedure

@InterfaceAudience.Private
public abstract class AbstractStateMachineNamespaceProcedure<TState>
extends StateMachineProcedure<MasterProcedureEnv,TState>
implements TableProcedureInterface

Base class for all the Namespace procedures that want to use a StateMachineProcedure. It provide some basic helpers like basic locking and basic toStringClassDetails().

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

Modifier and Type	Field and Description
private ProcedurePrepareLatch	syncLatch

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

NO_PROC_ID, NO_TIMEOUT

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractStateMachineNamespaceProcedure()
protected	AbstractStateMachineNamespaceProcedure(MasterProcedureEnv env)
protected	AbstractStateMachineNamespaceProcedure(MasterProcedureEnv env, ProcedurePrepareLatch latch)

Method Summary

Modifier and Type	Method and Description
protected Procedure.LockState	acquireLock(MasterProcedureEnv env) The user should override this method if they need a lock on an Entity.
protected abstract String	getNamespaceName()
TableName	getTableName()
abstract TableProcedureInterface.TableOperationType	getTableOperationType() Given an operation type we can take decisions about what to do with pending operations.
protected void	releaseLock(MasterProcedureEnv env) The user should override this method, and release lock if necessary.
protected void	releaseSyncLatch()
void	toStringClassDetails(StringBuilder sb) Extend the toString() information with the procedure details e.g.
protected boolean	waitInitialized(MasterProcedureEnv env) The Procedure.doAcquireLock(Object, ProcedureStore) will be split into two steps, first, it will call us to determine whether we need to wait for initialization, second, it will call Procedure.acquireLock(Object) to actually handle the lock for this procedure.

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

abort, addChildProcedure, deserializeStateData, execute, executeFromState, failIfAborted, getCurrentState, getCurrentStateId, getCycles, getInitialState, getState, getStateId, isRollbackSupported, isYieldAfterExecutionStep, isYieldBeforeExecuteFromState, rollback, rollbackState, serializeStateData, 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, 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, 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

Field Detail

syncLatch

private final ProcedurePrepareLatch syncLatch

Constructor Detail

AbstractStateMachineNamespaceProcedure

protected AbstractStateMachineNamespaceProcedure()

AbstractStateMachineNamespaceProcedure

protected AbstractStateMachineNamespaceProcedure(MasterProcedureEnv env)

AbstractStateMachineNamespaceProcedure

protected AbstractStateMachineNamespaceProcedure(MasterProcedureEnv env,
                                                 ProcedurePrepareLatch latch)

Method Detail

getNamespaceName

protected abstract String getNamespaceName()

getTableName

public TableName getTableName()

Specified by:

getTableName in interface TableProcedureInterface

Returns:

the name of the table the procedure is operating on

getTableOperationType

public abstract 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

Returns:

the operation type that the procedure is executing.

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 Procedure<MasterProcedureEnv>

Parameters:

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

waitInitialized

protected boolean waitInitialized(MasterProcedureEnv env)

Description copied from class: Procedure

The Procedure.doAcquireLock(Object, ProcedureStore) will be split into two steps, first, it will call us to determine whether we need to wait for initialization, second, it will call Procedure.acquireLock(Object) to actually handle the lock for this procedure.

This is because that when master restarts, we need to restore the lock state for all the procedures to not break the semantic if Procedure.holdLock(Object) is true. But the ProcedureExecutor will be started before the master finish initialization(as it is part of the initialization!), so we need to split the code into two steps, and when restore, we just restore the lock part and ignore the waitInitialized part. Otherwise there will be dead lock.

Overrides:

waitInitialized in class Procedure<MasterProcedureEnv>

Returns:

true means we need to wait until the environment has been initialized, otherwise true.

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 Procedure<MasterProcedureEnv>

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 Procedure<MasterProcedureEnv>

releaseSyncLatch

protected void releaseSyncLatch()