Modifier and Type	Class and Description
private class	SlaveController.SlaveLogReceiverThread Thread that listens for incoming messages from the master and applies chunks of log records to the local log files.

Modifier and Type	Field and Description
private String	dbname
private static final int	DEFAULT_SOCKET_TIMEOUT
private volatile long	highestLogInstant The instant of the latest log record received from the master and processed so far.
private volatile boolean	inReplicationSlaveMode Whether or not replication slave mode is still on.
private SlaveController.SlaveLogReceiverThread	logReceiverThread
private ReplicationLogScan	logScan
private LogToFile	logToFile
private RawStoreFactory	rawStoreFactory
private ReplicationMessageReceive	receiver
private ReplicationLogger	repLogger
private SlaveAddress	slaveAddr
private volatile boolean	startupSuccessful Whether or not this SlaveController has been successfully started, including setting up a connection with the master and starting the log receiver thread.

Access	Constructor and Description
public	SlaveController() Empty constructor required by Monitor.bootServiceModule

Method Summary

Modifier and Type	Method and Description
public void	boot(boolean Currently ignored create, Properties Properties used to start the service in the correct mode properties) Implements org.apache.derby.iapi.services.monitor.ModuleControl.boot. Used by Monitor.bootServiceModule to start the service.
public boolean	Returns: true if slave repliation is specified, meaning that this MasterController is a suitable implementation for the SlaveFactory service. False otherwise. canSupport(Properties The properties used to start replication startParams) Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport. Used by Monitor.bootServiceModule to check if this class is usable for replication.
private void	doFailover() Performs failover on this database.
public void	failover() Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.failover. Used to turn this slave instance of the database into a normal instance that clients can connect to, assuming that the connection with the master is down.
private String	Returns: a String containing the host name of the slave. getHostName() Used to return the host name of the slave.
private int	Returns: an Integer that represents the port number of the slave. getPortNumber() Used to return the port number of the slave.
private void	handleDisconnect(Exception The reason the connection to the master was lost e) Write the reason for the lost connection to the log (derby.log) and reconnect with the master.
private void	handleFatalException(Exception The fatal exception that is the reason for calling this method e) Handles fatal errors for slave replication functionality.
private boolean	Returns: true if the network connection is working, false otherwise isConnectedToMaster() Check if the repliation network connection to the master is working
public boolean	isStarted() Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.isStarted. Check whether or not slave replication mode has been successfully started.
private boolean	Returns: true if a connection has been set up with the master, false if the connection attempt timed out. setupConnection() Establish a connection with the replication master.
private void	startLogReceiverThread() Starts the LogReceiverThread that will listen for chunks of log records from the master and apply the log records to the local log file.
public void	startSlave(RawStoreFactory The RawStoreFactory for the database rawStore, LogFactory The LogFactory ensuring recoverability for this database logFac) Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.startSlave. Start slave replication.
public void	stop() Implements org.apache.derby.iapi.services.monitor.ModuleControl.stop. Will tear down the replication slave service.
private void	stopSlave() Will perform all work that is needed to stop replication
public void	stopSlave(boolean Determines whether or not an exception should be thrown when this method is called while the network connection to the master is up. forcedStop) Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.stopSlave. Stop replication slave mode.
private void	teardownNetwork()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

dbname	back to summary
private String dbname

DEFAULT_SOCKET_TIMEOUT	back to summary
private static final int DEFAULT_SOCKET_TIMEOUT

highestLogInstant	back to summary
private volatile long highestLogInstant The instant of the latest log record received from the master and processed so far. Used to check that master and slave log files are in synch

inReplicationSlaveMode	back to summary
private volatile boolean inReplicationSlaveMode Whether or not replication slave mode is still on. Will be set to false when slave replication is shut down. The value of this variable is checked after every timeout when trying to set up a connection to the master, and by the thread that applies log chunks received from the master.

logReceiverThread	back to summary
private SlaveController.SlaveLogReceiverThread logReceiverThread

logScan	back to summary
private ReplicationLogScan logScan

logToFile	back to summary
private LogToFile logToFile

rawStoreFactory	back to summary
private RawStoreFactory rawStoreFactory

receiver	back to summary
private ReplicationMessageReceive receiver

repLogger	back to summary
private ReplicationLogger repLogger

slaveAddr	back to summary
private SlaveAddress slaveAddr

startupSuccessful	back to summary
private volatile boolean startupSuccessful Whether or not this SlaveController has been successfully started, including setting up a connection with the master and starting the log receiver thread. The client connection that initiated slave replication mode on this database will not report that slave mode was successfully started (i.e., it will hang) until startupSuccessful has been set to true

startupSuccessful

back to summary

private volatile boolean startupSuccessful

Whether or not this SlaveController has been successfully started, including setting up a connection with the master and starting the log receiver thread. The client connection that initiated slave replication mode on this database will not report that slave mode was successfully started (i.e., it will hang) until startupSuccessful has been set to true

Constructor Detail

SlaveController	back to summary
public SlaveController() Empty constructor required by Monitor.bootServiceModule

Method Detail

boot	back to summary
public void boot(boolean create, Properties properties) throws StandardException Implements org.apache.derby.iapi.services.monitor.ModuleControl.boot. Used by Monitor.bootServiceModule to start the service. It will set up basic variables Parameters create:boolean Currently ignored properties:Properties Properties used to start the service in the correct mode Exceptions StandardException: Standard Derby exception policy, thrown on error.

boot

back to summary

public void boot(boolean create, Properties properties) throws StandardException

Implements org.apache.derby.iapi.services.monitor.ModuleControl.boot.

Used by Monitor.bootServiceModule to start the service. It will set up basic variables

Parameters

create:boolean: Currently ignored
properties:Properties: Properties used to start the service in the correct mode

Exceptions

StandardException:: Standard Derby exception policy, thrown on error.

canSupport back to summary

canSupport	back to summary
public boolean canSupport(Properties startParams) Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport. Used by Monitor.bootServiceModule to check if this class is usable for replication. To be usable, we require that slave replication mode is specified in startParams by checking that a property with key SlaveFactory.REPLICATION_MODE has the value SlaveFactory.SLAVE_MODE. Parameters startParams:Properties The properties used to start replication Returns:boolean true if slave repliation is specified, meaning that this MasterController is a suitable implementation for the SlaveFactory service. False otherwise. See Also `ModuleSupportable#canSupport`

public boolean canSupport(Properties startParams)

Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport.

Used by Monitor.bootServiceModule to check if this class is usable for replication. To be usable, we require that slave replication mode is specified in startParams by checking that a property with key SlaveFactory.REPLICATION_MODE has the value SlaveFactory.SLAVE_MODE.

Parameters

startParams:Properties: The properties used to start replication

Returns:boolean

true if slave repliation is specified, meaning that this MasterController is a suitable implementation for the SlaveFactory service. False otherwise.

See Also

ModuleSupportable#canSupport

doFailover back to summary

doFailover	back to summary
private void doFailover() Performs failover on this database. May be called because a failover command has been received from the master, or because a client has requested a failover after the network connection with the master has been lost. See Also `SlaveFactory#failover`

private void doFailover()

Performs failover on this database. May be called because a failover command has been received from the master, or because a client has requested a failover after the network connection with the master has been lost.

See Also: SlaveFactory#failover

failover	back to summary
public void failover() throws StandardException Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.failover. Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.failover. Used to turn this slave instance of the database into a normal instance that clients can connect to, assuming that the connection with the master is down. This is typically done in cases where a fatal error has happened on the master instance of the database, or when the master database is unreachable due to network problems. By calling failover, this slave instance of the database will be recovered so that all committed operations that have been received from the master are reflected here. On the other hand, operations from transactions where the commit log record has not been received from the master will not be reflected. Note that even though an operation has been executed (and even committed) on the master, it is not neccessarily reflected in the slave instance of the database. This depends on the replication strategy used by the MasterFactory. Exceptions StandardException: Thrown if slave is connected with master

failover

back to summary

public void failover() throws StandardException

Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.failover.

Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.failover.

Used to turn this slave instance of the database into a normal instance that clients can connect to, assuming that the connection with the master is down. This is typically done in cases where a fatal error has happened on the master instance of the database, or when the master database is unreachable due to network problems.

By calling failover, this slave instance of the database will be recovered so that all committed operations that have been received from the master are reflected here. On the other hand, operations from transactions where the commit log record has not been received from the master will not be reflected.

Note that even though an operation has been executed (and even committed) on the master, it is not neccessarily reflected in the slave instance of the database. This depends on the replication strategy used by the MasterFactory.

Exceptions

StandardException:: Thrown if slave is connected with master

getHostName	back to summary
private String getHostName() Used to return the host name of the slave. Returns:String a String containing the host name of the slave.

getHostName

back to summary

private String getHostName()

Used to return the host name of the slave.

Returns:String: a String containing the host name of the slave.

getPortNumber	back to summary
private int getPortNumber() Used to return the port number of the slave. Returns:int an Integer that represents the port number of the slave.

getPortNumber

back to summary

private int getPortNumber()

Used to return the port number of the slave.

Returns:int: an Integer that represents the port number of the slave.

handleDisconnect	back to summary
private void handleDisconnect(Exception e) Write the reason for the lost connection to the log (derby.log) and reconnect with the master. Once the network is up and running, a new LogReceiverThread is started. The method returns without doing anything if inReplicationSlaveMode=false, which means that stopSlave() has been called by another thread. Parameters e:Exception The reason the connection to the master was lost

handleDisconnect

back to summary

private void handleDisconnect(Exception e)

Write the reason for the lost connection to the log (derby.log) and reconnect with the master. Once the network is up and running, a new LogReceiverThread is started. The method returns without doing anything if inReplicationSlaveMode=false, which means that stopSlave() has been called by another thread.

Parameters

e:Exception: The reason the connection to the master was lost

handleFatalException	back to summary
private void handleFatalException(Exception e) Handles fatal errors for slave replication functionality. These are errors that requires us to stop replication. Calling this method has the following effects: 1) Debug messages are written to the log file (usually derby.log) if ReplicationLogger#LOG_REPLICATION_MESSAGES is true. 2) If the network connection is up, the master is notified of the problem. 3) All slave replication functionality is stopped, and the database is then shut down without being booted. The method will return without doing anything if inReplicationSlaveMode=false, meaning that stopSlave has been called. Parameters e:Exception The fatal exception that is the reason for calling this method

handleFatalException

back to summary

private void handleFatalException(Exception e)

Handles fatal errors for slave replication functionality. These are errors that requires us to stop replication. Calling this method has the following effects: 1) Debug messages are written to the log file (usually derby.log) if ReplicationLogger#LOG_REPLICATION_MESSAGES is true. 2) If the network connection is up, the master is notified of the problem. 3) All slave replication functionality is stopped, and the database is then shut down without being booted. The method will return without doing anything if inReplicationSlaveMode=false, meaning that stopSlave has been called.

Parameters

e:Exception: The fatal exception that is the reason for calling this method

isConnectedToMaster	back to summary
private boolean isConnectedToMaster() Check if the repliation network connection to the master is working Returns:boolean true if the network connection is working, false otherwise

isConnectedToMaster

back to summary

private boolean isConnectedToMaster()

Check if the repliation network connection to the master is working

Returns:boolean: true if the network connection is working, false otherwise

isStarted back to summary

isStarted	back to summary
public boolean isStarted() Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.isStarted. Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.isStarted. Check whether or not slave replication mode has been successfully started. Returns:boolean true if slave replication mode has started successfully, false if slave mode startup is not yet confirmed See Also `SlaveFactory#isStarted`

public boolean isStarted()

Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.isStarted.

Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.isStarted.

Check whether or not slave replication mode has been successfully started.

Returns:boolean: true if slave replication mode has started successfully, false if slave mode startup is not yet confirmed
See Also: SlaveFactory#isStarted

setupConnection	back to summary
private boolean setupConnection() throws StandardException Establish a connection with the replication master. Listens for a connection on the slavehost/port for DEFAULT_SOCKET_TIMEOUT milliseconds. Returns:boolean true if a connection has been set up with the master, false if the connection attempt timed out. Exceptions StandardException: if an unexpected exception occured that prevented a connection with the master.

setupConnection

back to summary

private boolean setupConnection() throws StandardException

Establish a connection with the replication master. Listens for a connection on the slavehost/port for DEFAULT_SOCKET_TIMEOUT milliseconds.

Returns:boolean

true if a connection has been set up with the master, false if the connection attempt timed out.

Exceptions

StandardException:: if an unexpected exception occured that prevented a connection with the master.

startLogReceiverThread	back to summary
private void startLogReceiverThread() Starts the LogReceiverThread that will listen for chunks of log records from the master and apply the log records to the local log file.

startSlave	back to summary
public void startSlave(RawStoreFactory rawStore, LogFactory logFac) throws StandardException Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.startSlave. Start slave replication. This method establishes a network connection with the associated replication master and starts a thread that applies operations received from the master (in the form of log records) to the local slave database. Parameters rawStore:RawStoreFactory The RawStoreFactory for the database logFac:LogFactory The LogFactory ensuring recoverability for this database Exceptions StandardException: Thrown if the slave could not be started.

startSlave

back to summary

public void startSlave(RawStoreFactory rawStore, LogFactory logFac) throws StandardException

Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.startSlave.

Start slave replication. This method establishes a network connection with the associated replication master and starts a thread that applies operations received from the master (in the form of log records) to the local slave database.

Parameters

rawStore:RawStoreFactory: The RawStoreFactory for the database
logFac:LogFactory: The LogFactory ensuring recoverability for this database

Exceptions

StandardException:: Thrown if the slave could not be started.

stop	back to summary
public void stop() Implements org.apache.derby.iapi.services.monitor.ModuleControl.stop. Will tear down the replication slave service.

stop

back to summary

public void stop()

Implements org.apache.derby.iapi.services.monitor.ModuleControl.stop.

Will tear down the replication slave service.

stopSlave	back to summary
private void stopSlave() throws StandardException Will perform all work that is needed to stop replication

stopSlave back to summary

stopSlave	back to summary
public void stopSlave(boolean forcedStop) throws StandardException Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.stopSlave. Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.stopSlave. Stop replication slave mode. Causes the database to abort the boot process, and should only be used when shutting down this database. If forcedStop is false, the method will fail with an exception if connected with the master. If forcedStop is true, the slave will be shut down even if connected to the master. A forcedStop value of true should only be used by system shutdown. Parameters forcedStop:boolean Determines whether or not an exception should be thrown when this method is called while the network connection to the master is up. Exceptions StandardException: Thrown if slave is connected with master and forcedStop is false. See Also `SlaveFactory#stopSlave`

public void stopSlave(boolean forcedStop) throws StandardException

Implements org.apache.derby.iapi.store.replication.slave.SlaveFactory.stopSlave.

Doc from org.apache.derby.iapi.store.replication.slave.SlaveFactory.stopSlave.

Stop replication slave mode. Causes the database to abort the boot process, and should only be used when shutting down this database. If forcedStop is false, the method will fail with an exception if connected with the master. If forcedStop is true, the slave will be shut down even if connected to the master. A forcedStop value of true should only be used by system shutdown.

Parameters

forcedStop:boolean: Determines whether or not an exception should be thrown when this method is called while the network connection to the master is up.

Exceptions

StandardException:: Thrown if slave is connected with master and forcedStop is false.

See Also

SlaveFactory#stopSlave

teardownNetwork	back to summary
private void teardownNetwork()

org.apache.derby.impl.store.replication.slave back to summary

private Class SlaveController.SlaveLogReceiverThread

Class Inheritance

extends Thread

java.lang.Object
java.lang.Thread
org.apache.derby.impl.store.replication.slave.SlaveController.SlaveLogReceiverThread

Thread that listens for incoming messages from the master and applies chunks of log records to the local log files.

Field Summary

Inherited from java.lang.Thread:: MAX_PRIORITY MIN_PRIORITY NORM_PRIORITY

Constructor Summary

Access	Constructor and Description
pack-priv	SlaveLogReceiverThread() Creates a new instance of `SlaveLogReceiverThread` with a debugging-friendly thread name.

Method Summary

Modifier and Type	Method and Description
private void	handleLogChunk(byte[] A chunk of log records received from the master logChunk) Parses a chunk of log received from the master, and applies the individual log records to the local log file.
public void	run() Overrides java.lang.Thread.run. Implements java.lang.Runnable.run. This method is run by the thread when it executes.

Constructor Detail

SlaveLogReceiverThread	back to summary
pack-priv SlaveLogReceiverThread() Creates a new instance of `SlaveLogReceiverThread` with a debugging-friendly thread name.

Method Detail

handleLogChunk	back to summary
private void handleLogChunk(byte[] logChunk) throws StandardException Parses a chunk of log received from the master, and applies the individual log records to the local log file. Parameters logChunk:byte[] A chunk of log records received from the master Exceptions StandardException: If the chunk of log records could not be parsed or the local log file is out of synch with the master log file.

handleLogChunk

back to summary

private void handleLogChunk(byte[] logChunk) throws StandardException

Parses a chunk of log received from the master, and applies the individual log records to the local log file.

Parameters

logChunk:byte[]: A chunk of log records received from the master

Exceptions

StandardException:: If the chunk of log records could not be parsed or the local log file is out of synch with the master log file.

run back to summary

run	back to summary
public void run() Overrides java.lang.Thread.run. Implements java.lang.Runnable.run. Doc from java.lang.Thread.run. This method is run by the thread when it executes. Subclasses of `Thread` may override this method. This method is not intended to be invoked directly. If this thread is a platform thread created with a `Runnable` task then invoking this method will invoke the task's `run` method. If this thread is a virtual thread then invoking this method directly does nothing.

public void run()

Overrides java.lang.Thread.run.

Implements java.lang.Runnable.run.

Doc from java.lang.Thread.run.

This method is run by the thread when it executes. Subclasses of Thread may override this method.

This method is not intended to be invoked directly. If this thread is a platform thread created with a Runnable task then invoking this method will invoke the task's run method. If this thread is a virtual thread then invoking this method directly does nothing.

public Class SlaveController

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class SlaveController.SlaveLogReceiverThread

Field Summary

Constructor Summary

Method Summary

Constructor Detail

Method Detail