com.sleepycat.je.rep.impl.node

Class ReplicaOutputThreadBase

java.lang.Object

java.lang.Thread

com.sleepycat.je.utilint.StoppableThread

com.sleepycat.je.rep.impl.node.ReplicaOutputThreadBase

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

ArbiterOutputThread, ReplicaOutputThread

public abstract class ReplicaOutputThreadBase
extends StoppableThread

The thread used to write responses asynchronously to the network, to avoid network stalls in the replica replay thread. This thread, like the Replica.ReplayThread, is created each time the node establishes contact with a new feeder and starts replaying the log from it. The inputs and outputs of this thread are schematically described as: outputQueue -> ReplicaOutputThread (does write) -> writes to network It's the third component of the three thread structure outlined in the Replica's class level comment.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field and Description
static Long	EOF
protected Exception	exception Thread exit exception.
protected boolean	groupAcksEnabled
static Long	HEARTBEAT_ACK One of two txn ID values that results in a heartbeat response when encountered in the write queue.
static Long	HEARTBEAT_ACK_TIMED Another txn ID that results in a heartbeat response when encountered in the write queue, and is used to mark a heartbeat response whose time spent in the queue is being measured.
protected int	heartbeatMs
protected Logger	logger
protected long	numGroupedAcks
protected BlockingQueue<Long>	outputQueue
protected Protocol	protocol
protected int	queueSize The size of the write queue.
protected RepImpl	repImpl
protected DataChannel	replicaFeederChannel
static Long	SHUTDOWN_ACK

Fields inherited from class com.sleepycat.je.utilint.StoppableThread

envImpl

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
ReplicaOutputThreadBase(RepImpl repImpl, BlockingQueue<Long> outputQueue, Protocol protocol, DataChannel replicaFeederChannel)

Method Summary

Modifier and Type	Method and Description
Exception	getException()
protected Logger	getLogger()
long	getNumGroupedAcks()
long	getOutputQueueSize() For testing only.
protected boolean	groupWriteAcks(long txnId) Writes out the acks that are currently queued in the output queue Returns true if it encountered an EOF or a request for a shutdown.
protected int	initiateSoftShutdown() Threads that use shutdownThread() must define this method.
void	run()
void	setOutputHook(TestHook<Object> outputHook)
abstract void	writeHeartbeat(Long txnId)
abstract void	writeReauthentication()

Methods inherited from class com.sleepycat.je.utilint.StoppableThread

cleanup, getSavedShutdownException, getTotalCpuTime, getTotalUserTime, handleUncaughtException, isShutdown, saveShutdownException, shutdownDone, shutdownThread

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

queueSize

protected final int queueSize

The size of the write queue.

heartbeatMs

protected final int heartbeatMs

exception

protected volatile Exception exception

Thread exit exception. It's non-null if the thread exited due to an exception. It's the responsibility of the main replica thread to propagate the exception across the thread boundary in this case.

repImpl

protected final RepImpl repImpl

outputQueue

protected final BlockingQueue<Long> outputQueue

protocol

protected final Protocol protocol

replicaFeederChannel

protected final DataChannel replicaFeederChannel

EOF

public static final Long EOF

HEARTBEAT_ACK

public static final Long HEARTBEAT_ACK

One of two txn ID values that results in a heartbeat response when encountered in the write queue.

HEARTBEAT_ACK_TIMED

public static final Long HEARTBEAT_ACK_TIMED

Another txn ID that results in a heartbeat response when encountered in the write queue, and is used to mark a heartbeat response whose time spent in the queue is being measured.

SHUTDOWN_ACK

public static final Long SHUTDOWN_ACK

groupAcksEnabled

protected final boolean groupAcksEnabled

numGroupedAcks

protected volatile long numGroupedAcks

logger

protected final Logger logger

Constructor Detail

ReplicaOutputThreadBase

public ReplicaOutputThreadBase(RepImpl repImpl,
                               BlockingQueue<Long> outputQueue,
                               Protocol protocol,
                               DataChannel replicaFeederChannel)

Method Detail

getLogger

protected Logger getLogger()

Specified by:

getLogger in class StoppableThread

Returns:

a logger to use when logging uncaught exceptions.

getException

public Exception getException()

getNumGroupedAcks

public long getNumGroupedAcks()

getOutputQueueSize

public long getOutputQueueSize()

For testing only.

setOutputHook

public void setOutputHook(TestHook<Object> outputHook)

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

writeReauthentication

public abstract void writeReauthentication()
                                    throws IOException

Throws:

IOException

writeHeartbeat

public abstract void writeHeartbeat(Long txnId)
                             throws IOException

Throws:

IOException

groupWriteAcks

protected boolean groupWriteAcks(long txnId)
                          throws IOException

Writes out the acks that are currently queued in the output queue Returns true if it encountered an EOF or a request for a shutdown.

Throws:

IOException

initiateSoftShutdown

protected int initiateSoftShutdown()

Description copied from class: StoppableThread

Threads that use shutdownThread() must define this method. It's invoked by shutdownThread as an attempt at a soft shutdown. This method makes provisions for this thread to exit on its own. The technique used to make the thread exit can vary based upon the nature of the service being provided by the thread. For example, the thread may be known to poll some shutdown flag on a periodic basis, or it may detect that a channel that it waits on has been closed by this method.

Overrides:

initiateSoftShutdown in class StoppableThread

Returns:

the amount of time in ms that the shutdownThread method will wait for the thread to exit. A -ve value means that the method will not wait. A zero value means it will wait indefinitely.