com.continuent.tungsten.replicator.extractor.postgresql
Class PostgreSQLSlonyExtractor

java.lang.Object
  com.continuent.tungsten.replicator.extractor.postgresql.PostgreSQLSlonyExtractor

All Implemented Interfaces:

RawExtractor, ReplicatorPlugin

public class PostgreSQLSlonyExtractor
extends java.lang.Object
implements RawExtractor

Class extracting events from Slony's log tables, generated by triggers. No running Slony deamons required.

Version:

1.0

Author:

Linas Virbalas

Constructor Summary

PostgreSQLSlonyExtractor()

Method Summary

void	configure(PluginContext context) Complete plug-in configuration.
DBMSEvent	extract() Extracts the next event. Extract the next available DBMSEvent from the database log.
DBMSEvent	extract(java.lang.String eventId) Extract starting after the event ID provided as an argument.
java.lang.String	getCurrentResourceEventId() Determines last transaction (log_txid) in the Slony log. Returns the last event ID committed in the database from which we are extracting.
java.lang.String	getDatabase()
java.lang.String	getHost()
java.lang.String	getPassword()
int	getPort()
java.lang.String	getSlonySchema()
java.lang.String	getUser()
void	prepare(PluginContext context) Prepare plug-in for use.
void	release(PluginContext context) Release all resources used by plug-in.
void	setDatabase(java.lang.String database) PostgreSQL database to connect to.
void	setHost(java.lang.String host)
void	setLastEventId(java.lang.String eventId) Set the value of the last event ID we have processed.
void	setPassword(java.lang.String password)
void	setPort(int port)
void	setSlonySchema(java.lang.String slonySchema)
void	setUser(java.lang.String user)

Methods inherited from class java.lang.Object

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

Constructor Detail

PostgreSQLSlonyExtractor

public PostgreSQLSlonyExtractor()

Method Detail

getHost

public java.lang.String getHost()

setHost

public void setHost(java.lang.String host)

getPort

public int getPort()

setPort

public void setPort(int port)

getDatabase

public java.lang.String getDatabase()

getSlonySchema

public java.lang.String getSlonySchema()

setDatabase

public void setDatabase(java.lang.String database)

PostgreSQL database to connect to. Important to specify, as Slony logs are installed on per database basis.

getUser

public java.lang.String getUser()

setUser

public void setUser(java.lang.String user)

getPassword

public java.lang.String getPassword()

setPassword

public void setPassword(java.lang.String password)

setSlonySchema

public void setSlonySchema(java.lang.String slonySchema)

extract

public DBMSEvent extract()
                  throws java.lang.InterruptedException,
                         ReplicatorException

Extracts the next event.

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

ReplicatorException

See Also:

RawExtractor.extract()

extract

public DBMSEvent extract(java.lang.String eventId)
                  throws java.lang.InterruptedException,
                         ReplicatorException

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:

eventId - Event ID at which to begin extracting

Returns:

DBMSEvent corresponding to the id

Throws:

java.lang.InterruptedException - Thrown if the applier is interrupted

ReplicatorException - Thrown if extractor processing fails

See Also:

RawExtractor.extract(java.lang.String)

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)

configure

public void configure(PluginContext context)
               throws ReplicatorException

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

Throws:

ReplicatorException - Thrown if configuration is incomplete or fails

See Also:

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

prepare

public void prepare(PluginContext context)
             throws ReplicatorException

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

Throws:

ReplicatorException - Thrown if resource allocation fails

See Also:

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

release

public void release(PluginContext context)
             throws ReplicatorException

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

Specified by:

release in interface ReplicatorPlugin

Throws:

ReplicatorException - Thrown if resource deallocation fails

See Also:

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

getCurrentResourceEventId

public java.lang.String getCurrentResourceEventId()
                                           throws ReplicatorException

Determines last transaction (log_txid) in the Slony log.

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

See Also:

RawExtractor.getCurrentResourceEventId()