org.apache.hadoop.hbase.master.procedure

Class ServerCrashProcedure

java.lang.Object

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

org.apache.hadoop.hbase.procedure2.StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.ServerCrashState>

org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure

All Implemented Interfaces:

Comparable<Procedure<MasterProcedureEnv>>, ServerProcedureInterface

@InterfaceAudience.Private
public class ServerCrashProcedure
extends StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.ServerCrashState>
implements ServerProcedureInterface

Handle crashed server. This is a port to ProcedureV2 of what used to be euphemistically called ServerShutdownHandler.

The procedure flow varies dependent on whether meta is assigned and if we are to split logs.

We come in here after ServerManager has noticed a server has expired. Procedures queued on the rpc should have been notified about fail and should be concurrently getting themselves ready to assign elsewhere.

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.ServerProcedureInterface

ServerProcedureInterface.ServerOperationType

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
ServerCrashProcedure() Used when deserializing from a procedure store; we'll construct one of these then call #deserializeStateData(InputStream).
ServerCrashProcedure(MasterProcedureEnv env, ServerName serverName, boolean shouldSplitWal, boolean carryingMeta) Call this constructor queuing up a Procedure.

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.ServerCrashState state) called to perform a single step of the specified 'state' of the procedure
protected MasterProcedureProtos.ServerCrashState	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.
ServerName	getServerName()
ServerProcedureInterface.ServerOperationType	getServerOperationType() Given an operation type we can take decisions about what to do with pending operations.
protected MasterProcedureProtos.ServerCrashState	getState(int stateId) Convert an ordinal (or state id) to an Enum (or more descriptive) state object.
protected int	getStateId(MasterProcedureProtos.ServerCrashState state) Convert the Enum (or more descriptive) state object to an ordinal (or state id).
boolean	hasMetaTableRegion()
protected boolean	isYieldBeforeExecuteFromState(MasterProcedureEnv env, MasterProcedureProtos.ServerCrashState state) For this procedure, yield at end of each successful flow step so that all crashed servers can make progress rather than do the default which has each procedure running to completion before we move to the next.
protected void	releaseLock(MasterProcedureEnv env) The user should override this method, and release lock if necessary.
protected void	rollbackState(MasterProcedureEnv env, MasterProcedureProtos.ServerCrashState 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.
protected boolean	shouldWaitClientAck(MasterProcedureEnv env) By default, the executor will keep the procedure result around util the eviction TTL is expired.
void	toStringClassDetails(StringBuilder sb) Extend the toString() information with the procedure details e.g.

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

addChildProcedure, execute, failIfAborted, getCurrentState, getCurrentStateId, getCycles, isEofState, isRollbackSupported, isYieldAfterExecutionStep, 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, 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, skipPersistence, toString, toStringClass, toStringDetails, toStringSimpleSB, updateMetricsOnFinish, updateMetricsOnSubmit, updateTimestamp, waitInitialized, wasExecuted

Methods inherited from class java.lang.Object

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

Constructor Detail

ServerCrashProcedure

public ServerCrashProcedure(MasterProcedureEnv env,
                            ServerName serverName,
                            boolean shouldSplitWal,
                            boolean carryingMeta)

Call this constructor queuing up a Procedure.

Parameters:

serverName - Name of the crashed server.

shouldSplitWal - True if we should split WALs as part of crashed server processing.

carryingMeta - True if carrying hbase:meta table region.

ServerCrashProcedure

public ServerCrashProcedure()

Used when deserializing from a procedure store; we'll construct one of these then call #deserializeStateData(InputStream). Do not use directly.

Method Detail

executeFromState

protected StateMachineProcedure.Flow executeFromState(MasterProcedureEnv env,
                                                      MasterProcedureProtos.ServerCrashState state)
                                               throws ProcedureSuspendedException,
                                                      ProcedureYieldException

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.ServerCrashState>

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

rollbackState

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

Description copied from class: StateMachineProcedure

called to perform the rollback of the specified state

Specified by:

rollbackState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.ServerCrashState>

state - state to rollback

Throws:

IOException - temporary failure, the rollback will retry later

getState

protected MasterProcedureProtos.ServerCrashState 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.ServerCrashState>

Parameters:

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

Returns:

the state enum object

getStateId

protected int getStateId(MasterProcedureProtos.ServerCrashState 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.ServerCrashState>

Parameters:

state - the state enum object

Returns:

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

getInitialState

protected MasterProcedureProtos.ServerCrashState 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.ServerCrashState>

Returns:

the initial state enum object

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.ServerCrashState>

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>

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

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.ServerCrashState>

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.ServerCrashState>

Parameters:

serializer - contains the serialized state

Throws:

IOException

getServerName

public ServerName getServerName()

Specified by:

getServerName in interface ServerProcedureInterface

Returns:

Name of this server instance.

hasMetaTableRegion

public boolean hasMetaTableRegion()

Specified by:

hasMetaTableRegion in interface ServerProcedureInterface

Returns:

True if this server has an hbase:meta table region.

getServerOperationType

public ServerProcedureInterface.ServerOperationType getServerOperationType()

Description copied from interface: ServerProcedureInterface

Given an operation type we can take decisions about what to do with pending operations. e.g. if we get a crash handler and we have some assignment operation pending we can abort those operations.

Specified by:

getServerOperationType in interface ServerProcedureInterface

Returns:

the operation type that the procedure is executing.

isYieldBeforeExecuteFromState

protected boolean isYieldBeforeExecuteFromState(MasterProcedureEnv env,
                                                MasterProcedureProtos.ServerCrashState state)

For this procedure, yield at end of each successful flow step so that all crashed servers can make progress rather than do the default which has each procedure running to completion before we move to the next. For crashed servers, especially if running with distributed log replay, we will want all servers to come along; we do not want the scenario where a server is stuck waiting for regions to online so it can replay edits.

Overrides:

isYieldBeforeExecuteFromState in class StateMachineProcedure<MasterProcedureEnv,MasterProcedureProtos.ServerCrashState>

state - the state we are going to execute next.

Returns:

Return true if the executor should yield before the execution of the specified step. Defaults to return false.

shouldWaitClientAck

protected boolean shouldWaitClientAck(MasterProcedureEnv env)

Description copied from class: Procedure

By default, the executor will keep the procedure result around util the eviction TTL is expired. The client can cut down the waiting time by requesting that the result is removed from the executor. In case of system started procedure, we can force the executor to auto-ack.

Overrides:

shouldWaitClientAck in class Procedure<MasterProcedureEnv>

Parameters:

env - the environment passed to the ProcedureExecutor

Returns:

true if the executor should wait the client ack for the result. Defaults to return true.

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