org.apache.hadoop.hbase.master.assignment

Class TransitRegionStateProcedure

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<TState>

org.apache.hadoop.hbase.master.procedure.AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

org.apache.hadoop.hbase.master.assignment.TransitRegionStateProcedure

All Implemented Interfaces:

Comparable<Procedure<MasterProcedureEnv>>, TableProcedureInterface

@InterfaceAudience.Private
public class TransitRegionStateProcedure
extends AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

The procedure to deal with the state transition of a region. A region with a TRSP in place is called RIT, i.e, RegionInTransition.

It can be used to assign/unassign/reopen/move a region, and for unassign(MasterProcedureEnv, RegionInfo) and reopen(MasterProcedureEnv, RegionInfo), you do not need to specify a target server, and for assign(MasterProcedureEnv, RegionInfo, ServerName) and move(MasterProcedureEnv, RegionInfo, ServerName), if you want to you can provide a target server. And for move(MasterProcedureEnv, RegionInfo, ServerName), if you do not specify a targetServer, we will select one randomly.

The typical state transition for assigning a region is:

 GET_ASSIGN_CANDIDATE ------> OPEN -----> CONFIRM_OPENED
 

Notice that, if there are failures we may go back to the GET_ASSIGN_CANDIDATE state to try again.

The typical state transition for unassigning a region is:

 CLOSE -----> CONFIRM_CLOSED
 

Here things go a bit different, if there are failures, especially that if there is a server crash, we will go to the GET_ASSIGN_CANDIDATE state to bring the region online first, and then go through the normal way to unassign it.

The typical state transition for reopening/moving a region is:

 CLOSE -----> CONFIRM_CLOSED -----> GET_ASSIGN_CANDIDATE ------> OPEN -----> CONFIRM_OPENED
 

The retry logic is the same with the above assign/unassign.

Notice that, although we allow specify a target server, it just acts as a candidate, we do not guarantee that the region will finally be on the target server. If this is important for you, you should check whether the region is on the target server after the procedure is finished.

When you want to schedule a TRSP, please check whether there is still one for this region, and the check should be under the RegionStateNode lock. We will remove the TRSP from a RegionStateNode when we are done, see the code in reportTransition method below. There could be at most one TRSP for a give region.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TransitRegionStateProcedure.TransitionType

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 ServerName	assignCandidate
private boolean	forceNewPlan
private org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState	initialState
private org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState	lastState
private static org.slf4j.Logger	LOG
private RegionRemoteProcedureBase	remoteProc
private RetryCounter	retryCounter
private TransitRegionStateProcedure.TransitionType	type

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

Fields inherited from interface org.apache.hadoop.hbase.master.procedure.TableProcedureInterface

DUMMY_NAMESPACE_TABLE_NAME

Constructor Summary

Constructors

Modifier	Constructor and Description
	TransitRegionStateProcedure()
protected	TransitRegionStateProcedure(MasterProcedureEnv env, RegionInfo hri, ServerName assignCandidate, boolean forceNewPlan, TransitRegionStateProcedure.TransitionType type)

Method Summary

Modifier and Type	Method and Description
static TransitRegionStateProcedure	assign(MasterProcedureEnv env, RegionInfo region, ServerName targetServer)
(package private) void	attachRemoteProc(RegionRemoteProcedureBase proc)
private void	closeRegion(MasterProcedureEnv env, RegionStateNode regionNode)
private StateMachineProcedure.Flow	confirmClosed(MasterProcedureEnv env, RegionStateNode regionNode)
private StateMachineProcedure.Flow	confirmOpened(MasterProcedureEnv env, RegionStateNode regionNode)
private static TransitRegionStateProcedure.TransitionType	convert(org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionTransitionType type)
private static org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionTransitionType	convert(TransitRegionStateProcedure.TransitionType type)
protected void	deserializeStateData(ProcedureStateSerializer serializer) Called on store load to allow the user to decode the previously serialized state.
protected Procedure[]	execute(MasterProcedureEnv env) The main code of the procedure.
protected StateMachineProcedure.Flow	executeFromState(MasterProcedureEnv env, org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState state) called to perform a single step of the specified 'state' of the procedure
protected org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState	getInitialState() Return the initial state object that will be used for the first call to executeFromState().
protected ProcedureMetrics	getProcedureMetrics(MasterProcedureEnv env) Override this method to provide procedure specific counters for submitted count, failed count and time histogram.
private RegionStateNode	getRegionStateNode(MasterProcedureEnv env)
protected org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState	getState(int stateId) Convert an ordinal (or state id) to an Enum (or more descriptive) state object.
protected int	getStateId(org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState state) Convert the Enum (or more descriptive) state object to an ordinal (or state id).
TableProcedureInterface.TableOperationType	getTableOperationType() Given an operation type we can take decisions about what to do with pending operations.
static TransitRegionStateProcedure	move(MasterProcedureEnv env, RegionInfo region, ServerName targetServer)
private void	openRegion(MasterProcedureEnv env, RegionStateNode regionNode)
private void	queueAssign(MasterProcedureEnv env, RegionStateNode regionNode)
static TransitRegionStateProcedure	reopen(MasterProcedureEnv env, RegionInfo region)
void	reportTransition(MasterProcedureEnv env, RegionStateNode regionNode, ServerName serverName, org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode code, long seqId, long procId)
protected void	rollbackState(MasterProcedureEnv env, org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState state) called to perform the rollback of the specified state
protected void	serializeStateData(ProcedureStateSerializer serializer) The user-level code of the procedure may have some state to persist (e.g.
void	serverCrashed(MasterProcedureEnv env, RegionStateNode regionNode, ServerName serverName)
private void	setInitalAndLastState()
private static TransitRegionStateProcedure	setOwner(MasterProcedureEnv env, TransitRegionStateProcedure proc)
protected boolean	setTimeoutFailure(MasterProcedureEnv env) At end of timeout, wake ourselves up so we run again.
(package private) void	stateLoaded(AssignmentManager am, RegionStateNode regionNode)
void	toStringClassDetails(StringBuilder sb) Extend the toString() information with the procedure details e.g.
static TransitRegionStateProcedure	unassign(MasterProcedureEnv env, RegionInfo region)
(package private) void	unattachRemoteProc(RegionRemoteProcedureBase proc)
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.master.procedure.AbstractStateMachineRegionProcedure

acquireLock, checkTableModifiable, getRegion, getTableName, holdLock, releaseLock, setFailure, setRegion

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

checkOnline, getUser, getWALRegionDir, preflightChecks, releaseSyncLatch, setUser

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

abort, addChildProcedure, failIfAborted, getCurrentState, getCurrentStateId, getCycles, isEofState, isRollbackSupported, 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, 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

LOG

private static final org.slf4j.Logger LOG

type

private TransitRegionStateProcedure.TransitionType type

initialState

private org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState initialState

lastState

private org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState lastState

assignCandidate

private ServerName assignCandidate

forceNewPlan

private boolean forceNewPlan

retryCounter

private RetryCounter retryCounter

remoteProc

private RegionRemoteProcedureBase remoteProc

Constructor Detail

TransitRegionStateProcedure

public TransitRegionStateProcedure()

TransitRegionStateProcedure

protected TransitRegionStateProcedure(MasterProcedureEnv env,
                                      RegionInfo hri,
                                      ServerName assignCandidate,
                                      boolean forceNewPlan,
                                      TransitRegionStateProcedure.TransitionType type)

Method Detail

setInitalAndLastState

private void setInitalAndLastState()

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 AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Returns:

the operation type that the procedure is executing.

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 AbstractStateMachineTableProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Returns:

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

queueAssign

private void queueAssign(MasterProcedureEnv env,
                         RegionStateNode regionNode)
                  throws ProcedureSuspendedException

Throws:

ProcedureSuspendedException

openRegion

private void openRegion(MasterProcedureEnv env,
                        RegionStateNode regionNode)
                 throws IOException

Throws:

IOException

confirmOpened

private StateMachineProcedure.Flow confirmOpened(MasterProcedureEnv env,
                                                 RegionStateNode regionNode)
                                          throws IOException

Throws:

IOException

closeRegion

private void closeRegion(MasterProcedureEnv env,
                         RegionStateNode regionNode)
                  throws IOException

Throws:

IOException

confirmClosed

private StateMachineProcedure.Flow confirmClosed(MasterProcedureEnv env,
                                                 RegionStateNode regionNode)
                                          throws IOException

Throws:

IOException

execute

protected Procedure[] execute(MasterProcedureEnv env)
                       throws ProcedureSuspendedException,
                              ProcedureYieldException,
                              InterruptedException

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.

Overrides:

execute in class StateMachineProcedure<MasterProcedureEnv,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

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.

Throws:

ProcedureSuspendedException - Signal to the executor that Procedure has suspended itself and has set itself up waiting for an external event to wake it back up again.

ProcedureYieldException - the procedure will be added back to the queue and retried later.

InterruptedException - the procedure will be added back to the queue and retried later.

getRegionStateNode

private RegionStateNode getRegionStateNode(MasterProcedureEnv env)

executeFromState

protected StateMachineProcedure.Flow executeFromState(MasterProcedureEnv env,
                                                      org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState state)
                                               throws ProcedureSuspendedException,
                                                      ProcedureYieldException,
                                                      InterruptedException

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,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

state - state to execute

Returns:

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

Throws:

ProcedureSuspendedException

ProcedureYieldException

InterruptedException

setTimeoutFailure

protected boolean setTimeoutFailure(MasterProcedureEnv env)

At end of timeout, wake ourselves up so we run again.

Overrides:

setTimeoutFailure in class Procedure<MasterProcedureEnv>

Returns:

true to let the framework handle the timeout as abort, false in case the procedure handled the timeout itself.

reportTransition

public void reportTransition(MasterProcedureEnv env,
                             RegionStateNode regionNode,
                             ServerName serverName,
                             org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode code,
                             long seqId,
                             long procId)
                      throws IOException

Throws:

IOException

serverCrashed

public void serverCrashed(MasterProcedureEnv env,
                          RegionStateNode regionNode,
                          ServerName serverName)
                   throws IOException

Throws:

IOException

attachRemoteProc

void attachRemoteProc(RegionRemoteProcedureBase proc)

unattachRemoteProc

void unattachRemoteProc(RegionRemoteProcedureBase proc)

stateLoaded

void stateLoaded(AssignmentManager am,
                 RegionStateNode regionNode)

rollbackState

protected void rollbackState(MasterProcedureEnv env,
                             org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState state)
                      throws IOException,
                             InterruptedException

Description copied from class: StateMachineProcedure

called to perform the rollback of the specified state

Specified by:

rollbackState in class StateMachineProcedure<MasterProcedureEnv,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

state - state to rollback

Throws:

IOException - temporary failure, the rollback will retry later

InterruptedException

getState

protected org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState 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,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Parameters:

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

Returns:

the state enum object

getStateId

protected int getStateId(org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState 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,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Parameters:

state - the state enum object

Returns:

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

getInitialState

protected org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState 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,org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Returns:

the initial state enum object

convert

private static TransitRegionStateProcedure.TransitionType convert(org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionTransitionType type)

convert

private static org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionTransitionType convert(TransitRegionStateProcedure.TransitionType type)

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 AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

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 AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Parameters:

serializer - contains the serialized state

Throws:

IOException

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

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 AbstractStateMachineRegionProcedure<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos.RegionStateTransitionState>

Parameters:

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

setOwner

private static TransitRegionStateProcedure setOwner(MasterProcedureEnv env,
                                                    TransitRegionStateProcedure proc)

assign

public static TransitRegionStateProcedure assign(MasterProcedureEnv env,
                                                 RegionInfo region,
                                                 @Nullable
                                                 ServerName targetServer)

unassign

public static TransitRegionStateProcedure unassign(MasterProcedureEnv env,
                                                   RegionInfo region)

reopen

public static TransitRegionStateProcedure reopen(MasterProcedureEnv env,
                                                 RegionInfo region)

move

public static TransitRegionStateProcedure move(MasterProcedureEnv env,
                                               RegionInfo region,
                                               @Nullable
                                               ServerName targetServer)