io.debezium.connector.postgresql.connection

Class PostgresReplicationConnection

java.lang.Object

io.debezium.jdbc.JdbcConnection

io.debezium.connector.postgresql.connection.PostgresReplicationConnection

All Implemented Interfaces:

ReplicationConnection, AutoCloseable

public class PostgresReplicationConnection
extends JdbcConnection
implements ReplicationConnection

Implementation of a ReplicationConnection for Postgresql. Note that replication connections in PG cannot execute regular statements but only a limited number of replication-related commands.

Author:

Horia Chiorean (hchiorea@redhat.com)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	PostgresReplicationConnection.ReplicationConnectionBuilder

Nested classes/interfaces inherited from class io.debezium.jdbc.JdbcConnection

JdbcConnection.CallPreparer, JdbcConnection.ConnectionFactory, JdbcConnection.Operations, JdbcConnection.ResultSetConsumer, JdbcConnection.SingleParameterResultSetConsumer, JdbcConnection.StatementFactory, JdbcConnection.StatementPreparer

Nested classes/interfaces inherited from interface io.debezium.connector.postgresql.connection.ReplicationConnection

ReplicationConnection.Builder

Field Summary

Fields

Modifier and Type	Field and Description
private long	defaultStartingPos
private boolean	dropSlotOnClose
private static org.slf4j.Logger	LOGGER
private Configuration	originalConfig
private String	pluginName
private String	slotName
private Integer	statusUpdateIntervalMillis

Constructor Summary

Constructors

Modifier	Constructor and Description
private	PostgresReplicationConnection(Configuration config, String slotName, String pluginName, boolean dropSlotOnClose, Integer statusUpdateIntervalMillis) Creates a new replication connection with the given params.

Method Summary

Modifier and Type	Method and Description
void	close()
private ReplicationStream	createReplicationStream(org.postgresql.replication.LogSequenceNumber lsn)
protected static void	defaultSettings(Configuration.Builder builder)
protected void	initReplicationSlot()
protected org.postgresql.PGConnection	pgConnection()
ReplicationStream	startStreaming() Opens a stream for reading logical replication changes from the last known position of the slot for which the connection was opened.
ReplicationStream	startStreaming(Long offset) Opens a stream for reading logical replication changes from a given LSN position.

Methods inherited from class io.debezium.jdbc.JdbcConnection

call, columnsFor, columnsFor, config, connect, connection, connectionString, database, execute, execute, isConnected, patternBasedFactory, patternBasedFactory, prepareQuery, prepareQuery, prepareQuery, prepareUpdate, print, print, query, query, readAllCatalogNames, readAllSchemaNames, readAllTableNames, readSchema, readTableNames, readTypeInfo, setAutoCommit, tableTypes, username

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.debezium.connector.postgresql.connection.ReplicationConnection

builder, format, isConnected

Field Detail

LOGGER

private static org.slf4j.Logger LOGGER

slotName

private final String slotName

pluginName

private final String pluginName

dropSlotOnClose

private final boolean dropSlotOnClose

originalConfig

private final Configuration originalConfig

statusUpdateIntervalMillis

private final Integer statusUpdateIntervalMillis

defaultStartingPos

private long defaultStartingPos

Constructor Detail

PostgresReplicationConnection

private PostgresReplicationConnection(Configuration config,
                                      String slotName,
                                      String pluginName,
                                      boolean dropSlotOnClose,
                                      Integer statusUpdateIntervalMillis)

Creates a new replication connection with the given params.

Parameters:

config - the JDBC configuration for the connection; may not be null

slotName - the name of the DB slot for logical replication; may not be null

pluginName - the name of the server side plugin used for streaming changes; may not be null;

dropSlotOnClose - whether the replication slot should be dropped once the connection is closed

statusUpdateIntervalMillis - the number of milli-seconds at which the replication connection should periodically send status updates to the server

Method Detail

initReplicationSlot

protected void initReplicationSlot()
                            throws SQLException

Throws:

SQLException

startStreaming

public ReplicationStream startStreaming()
                                 throws SQLException

Description copied from interface: ReplicationConnection

Opens a stream for reading logical replication changes from the last known position of the slot for which the connection was opened. The last known position is based on the server's confirmed_flush_lsn value from the pg_replication_slots table.

If there is no "last known value" (i.e. the connection is for a newly created slot) then the Postgres server will start streaming changes from that last position reported during this connection's creation.

Specified by:

startStreaming in interface ReplicationConnection

Returns:

a PGReplicationStream from which data is read; never null

Throws:

SQLException - if there is a problem obtaining the replication stream

startStreaming

public ReplicationStream startStreaming(Long offset)
                                 throws SQLException

Description copied from interface: ReplicationConnection

Opens a stream for reading logical replication changes from a given LSN position.

Note that it is possible for a server to have recycled old WAL segments (see the wal_keep_segments setting). If that is the case, then even though a LSN number may be valid, the server will not stream back any changes because they are not available.

Specified by:

startStreaming in interface ReplicationConnection

Parameters:

offset - a value representing the WAL sequence number where replication should start from; if the value is null or negative, this behaves exactly like ReplicationConnection.startStreaming().

Returns:

a PGReplicationStream from which data is read; never null

Throws:

SQLException - if anything fails

See Also:

LogSequenceNumber

pgConnection

protected org.postgresql.PGConnection pgConnection()
                                            throws SQLException

Throws:

SQLException

createReplicationStream

private ReplicationStream createReplicationStream(org.postgresql.replication.LogSequenceNumber lsn)
                                           throws SQLException

Throws:

SQLException

close

public void close()

Specified by:

close in interface AutoCloseable

Overrides:

close in class JdbcConnection

defaultSettings

protected static void defaultSettings(Configuration.Builder builder)