Package io.debezium.connector.postgresql.connection

Interface ReplicationConnection

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

PostgresReplicationConnection

@NotThreadSafe
public interface ReplicationConnection
extends AutoCloseable

A Postgres logical streaming replication connection. Replication connections are established for a slot and a given plugin and WAL offset tracking is specific to the [database name, plugin name, slot name] triple.

Author:

Horia Chiorean (hchiorea@redhat.com)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ReplicationConnection.Builder	A builder for ReplicationConnection

Method Summary

Modifier and Type	Method	Description
static ReplicationConnection.Builder	builder(PostgresConnectorConfig config)	Creates a new ReplicationConnection.Builder instance which can be used for creating replication connections.
Optional<SlotCreationResult>	createReplicationSlot()	Creates a new replication slot with the given option and returns the result of the command, which may contain results (depending on postgres versions)
void	initConnection()	Forces the connection to be created, is called by startStreaming, but can be called manually in cases where we want the connection but not to to start streaming yet.
boolean	isConnected()	Checks whether this connection is open or not
void	reconnect()
ReplicationStream	startStreaming(Lsn offset, WalPositionLocator walPosition)	Opens a stream for reading logical replication changes from a given LSN position.
ReplicationStream	startStreaming(WalPositionLocator walPosition)	Opens a stream for reading logical replication changes from the last known position of the slot for which the connection was opened.

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

startStreaming

ReplicationStream startStreaming(WalPositionLocator walPosition)
                          throws SQLException,
                                 InterruptedException

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.

Returns:

a PGReplicationStream from which data is read; never null

Throws:

SQLException - if there is a problem obtaining the replication stream

InterruptedException

startStreaming

ReplicationStream startStreaming(Lsn offset,
                                 WalPositionLocator walPosition)
                          throws SQLException,
                                 InterruptedException

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.

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 #startStreaming().

Returns:

a PGReplicationStream from which data is read; never null

Throws:

SQLException - if anything fails

InterruptedException

See Also:

LogSequenceNumber

createReplicationSlot

Optional<SlotCreationResult> createReplicationSlot()
                                            throws SQLException

Creates a new replication slot with the given option and returns the result of the command, which may contain results (depending on postgres versions)

Throws:

SQLException - if anything fails

initConnection

void initConnection()
             throws SQLException,
                    InterruptedException

Forces the connection to be created, is called by startStreaming, but can be called manually in cases where we want the connection but not to to start streaming yet. Can be called multiple times

Throws:

SQLException

InterruptedException

isConnected

boolean isConnected()
             throws SQLException

Checks whether this connection is open or not

Returns:

true if this connection is open, false otherwise

Throws:

SQLException - if anything unexpected fails

builder

static ReplicationConnection.Builder builder(PostgresConnectorConfig config)

Creates a new ReplicationConnection.Builder instance which can be used for creating replication connections.

Parameters:

config - a PostgresConnectorConfig instance; may not be null

Returns:

a builder, never null

reconnect

void reconnect()
        throws SQLException

Throws:

SQLException