com.continuent.tungsten.replicator.extractor
Class DummyExtractor

java.lang.Object
  com.continuent.tungsten.replicator.extractor.DummyExtractor

All Implemented Interfaces:

RawExtractor, ReplicatorPlugin

public class DummyExtractor
extends java.lang.Object
implements RawExtractor

This class defines a DummyExtractor

Version:

1.0

Author:

Teemu Ollakka

Constructor Summary

DummyExtractor()

Method Summary

void	configure(PluginContext context) Complete plug-in configuration.
DBMSEvent	extract() Extract the next available DBMSEvent from the database log.
DBMSEvent	extract(java.lang.String trxId) Extract starting after the event ID provided as an argument.
java.lang.String	getCurrentResourceEventId() Returns the last event ID committed in the database from which we are extracting.
int	getNFrags() Number of fragments per transaction.
java.lang.Integer	getNTrx() Get number of DBMSEvents that will be generated by dummy extractor.
void	prepare(PluginContext context) Prepare plug-in for use.
void	release(PluginContext context) Release all resources used by plug-in.
void	setLastEventId(java.lang.String eventId) Set the value of the last event ID we have processed.
void	setNFrags(int frags)
void	setNTrx(java.lang.Integer i) Set number of DBMSEvents that will be generated by dummy extractor.

Methods inherited from class java.lang.Object

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

Constructor Detail

DummyExtractor

public DummyExtractor()

Method Detail

setNTrx

public void setNTrx(java.lang.Integer i)

Set number of DBMSEvents that will be generated by dummy extractor.

Parameters:

i -

getNTrx

public java.lang.Integer getNTrx()

Get number of DBMSEvents that will be generated by dummy extractor.

Returns:

number of transactions

getNFrags

public int getNFrags()

Number of fragments per transaction.

setNFrags

public void setNFrags(int frags)

extract

public DBMSEvent extract()
                  throws java.lang.InterruptedException

Extract the next available DBMSEvent from the database log.

Specified by:

extract in interface RawExtractor

Returns:

next DBMSEvent found in the logs

Throws:

java.lang.InterruptedException

See Also:

RawExtractor.extract()

extract

public DBMSEvent extract(java.lang.String trxId)

Extract starting after the event ID provided as an argument. This is equivalent to invoking setLastEventId() followed by extract().

Specified by:

extract in interface RawExtractor

Parameters:

trxId - Event ID at which to begin extracting

Returns:

DBMSEvent corresponding to the id

See Also:

RawExtractor.extract(java.lang.String)

configure

public void configure(PluginContext context)

Complete plug-in configuration. This is called after setters are invoked at the time that the replicator goes through configuration.

Specified by:

configure in interface ReplicatorPlugin

See Also:

ReplicatorPlugin.configure(com.continuent.tungsten.replicator.plugin.PluginContext)

prepare

public void prepare(PluginContext context)

Prepare plug-in for use. This method is assumed to allocate all required resources. It is called before the plug-in performs any operations.

Specified by:

prepare in interface ReplicatorPlugin

See Also:

ReplicatorPlugin.prepare(com.continuent.tungsten.replicator.plugin.PluginContext)

release

public void release(PluginContext context)

Release all resources used by plug-in. This is called before the plug-in is deallocated.

Specified by:

release in interface ReplicatorPlugin

See Also:

ReplicatorPlugin.release(com.continuent.tungsten.replicator.plugin.PluginContext)

setLastEventId

public void setLastEventId(java.lang.String eventId)
                    throws ReplicatorException

Set the value of the last event ID we have processed. The extractor is responsible for returning the next event ID in sequence after this one the next time extract() is called.

Specified by:

setLastEventId in interface RawExtractor

Parameters:

eventId - Event ID at which to begin extracting

Throws:

ReplicatorException

See Also:

RawExtractor.setLastEventId(java.lang.String)

getCurrentResourceEventId

public java.lang.String getCurrentResourceEventId()
                                           throws ReplicatorException,
                                                  java.lang.InterruptedException

Returns the last event ID committed in the database from which we are extracting. It is used to help synchronize state between the database and the transaction history log. Values returned from this call must correspond with the last extracted DBMSEvent.eventId as follows:

1. If the returned value is greater than DBMSEvent.eventId, the database has more recent updates
2. If the returned value is equal to DBMSEvent.eventId, all events have been extracted

It should not be possible to receive a value that is less than the last extracted DBMSEvent.eventId as this implies that the extractor is somehow ahead of the state of the database, which would be inconsistent.

Specified by:

getCurrentResourceEventId in interface RawExtractor

Returns:

A current event ID that can be compared with event IDs in DBMSEvent

Throws:

ReplicatorException

java.lang.InterruptedException

See Also:

RawExtractor.getCurrentResourceEventId()