org.apache.derby.impl.store.replication.net

Class ReplicationMessageTransmit

java.lang.Object

org.apache.derby.impl.store.replication.net.ReplicationMessageTransmit

public class ReplicationMessageTransmit
extends java.lang.Object

Used to send replication messages to the slave. Called by the Master controller to transmit replication messages wrapped in a ReplicationMessage object to a receiver. The receiver is implemented by the ReplicationMessageReceive class.

Constructor Summary

Constructors

Constructor and Description
ReplicationMessageTransmit(SlaveAddress slaveAddress) Constructor initializes the slave address used in replication.

Method Summary

Modifier and Type	Method and Description
void	initConnection(int timeout, long synchOnInstant) Used to create a Socket connection to the slave and establish compatibility with the database version of the slave by comparing the UID's of the ReplicationMessage classes of the master and the slave.
void	sendMessage(ReplicationMessage message) Used to send a replication message to the slave.
ReplicationMessage	sendMessageWaitForReply(ReplicationMessage message) Send a replication message to the slave and return the message received as a response.
void	tearDown() Tear down the network connection established with the other replication peer

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReplicationMessageTransmit

public ReplicationMessageTransmit(SlaveAddress slaveAddress)

Constructor initializes the slave address used in replication.

Parameters:

slaveAddress - contains the address (host name and port number) of the slave to connect to.

Method Detail

initConnection

public void initConnection(int timeout,
                           long synchOnInstant)
                    throws java.io.IOException,
                           StandardException,
                           java.lang.ClassNotFoundException

Used to create a Socket connection to the slave and establish compatibility with the database version of the slave by comparing the UID's of the ReplicationMessage classes of the master and the slave.

Parameters:

timeout - the amount of time for which the connection should block before being established.

synchOnInstant - the master log instant, used to check that the master and slave log files are in synch. If no chunks of log records have been shipped to the slave yet, this is the end position in the current log file. If a chunk of log has been shipped, this is the instant of the log record shipped last. Note that there is a difference!

Throws:

java.io.IOException - if an exception occurs while trying to create the SocketConnection class or open a connection.

StandardException - If an error message is received from the server indicating incompatible software versions of master and slave.

java.lang.ClassNotFoundException - Class of a serialized object cannot be found.

tearDown

public void tearDown()
              throws java.io.IOException

Tear down the network connection established with the other replication peer

Throws:

java.io.IOException - if an exception occurs while trying to tear down the network connection

sendMessage

public void sendMessage(ReplicationMessage message)
                 throws java.io.IOException

Used to send a replication message to the slave.

Parameters:

message - a ReplicationMessage object that contains the message to be transmitted.

Throws:

java.io.IOException - 1) if an exception occurs while transmitting the message. 2) if the connection handle is invalid.

sendMessageWaitForReply

public ReplicationMessage sendMessageWaitForReply(ReplicationMessage message)
                                           throws java.io.IOException,
                                                  StandardException

Send a replication message to the slave and return the message received as a response. Will only wait DEFAULT_MESSAGE_RESPONSE_TIMEOUT millis for the response message. If not received when the wait times out, no message is returned. The method is synchronized to guarantee that only one thread will be waiting for a response message at any time.

Parameters:

message - a ReplicationMessage object that contains the message to be transmitted.

Returns:

the response message

Throws:

java.io.IOException - 1) if an exception occurs while sending or receiving a message. 2) if the connection handle is invalid.

StandardException - if the response message has not been received after DEFAULT_MESSAGE_RESPONSE_TIMEOUT millis