org.apache.zookeeper.server

Class SyncRequestProcessor

java.lang.Object

java.lang.Thread

org.apache.zookeeper.server.ZooKeeperThread

org.apache.zookeeper.server.ZooKeeperCriticalThread

org.apache.zookeeper.server.SyncRequestProcessor

All Implemented Interfaces:

Runnable, RequestProcessor

public class SyncRequestProcessor
extends ZooKeeperCriticalThread
implements RequestProcessor

This RequestProcessor logs requests to disk. It batches the requests to do the io efficiently. The request is not passed to the next RequestProcessor until its log has been synced to disk. SyncRequestProcessor is used in 3 different cases 1. Leader - Sync request to disk and forward it to AckRequestProcessor which send ack back to itself. 2. Follower - Sync request to disk and forward request to SendAckRequestProcessor which send the packets to leader. SendAckRequestProcessor is flushable which allow us to force push packets to leader. 3. Observer - Sync committed request to disk (received as INFORM packet). It never send ack back to the leader, so the nextProcessor will be null. This change the semantic of txnlog on the observer since it only contains committed txns.

Nested Class Summary

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

Thread.State, Thread.UncaughtExceptionHandler

Nested classes/interfaces inherited from interface org.apache.zookeeper.server.RequestProcessor

RequestProcessor.RequestProcessorException

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
SyncRequestProcessor(ZooKeeperServer zks, RequestProcessor nextProcessor)

Method Summary

Modifier and Type	Method and Description
static int	getSnapCount() used by tests to get the snapcount
void	processRequest(Request request)
void	run()
static void	setSnapCount(int count) used by tests to check for changing snapcounts
void	shutdown()

Methods inherited from class org.apache.zookeeper.server.ZooKeeperCriticalThread

handleException

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

Constructor Detail

SyncRequestProcessor

public SyncRequestProcessor(ZooKeeperServer zks,
                            RequestProcessor nextProcessor)

Method Detail

setSnapCount

public static void setSnapCount(int count)

used by tests to check for changing snapcounts

Parameters:

count -

getSnapCount

public static int getSnapCount()

used by tests to get the snapcount

Returns:

the snapcount

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

shutdown

public void shutdown()

Specified by:

shutdown in interface RequestProcessor

processRequest

public void processRequest(Request request)

Specified by:

processRequest in interface RequestProcessor