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 and Description
static interface	ReplicationConnection.Builder A builder for ReplicationConnection

Method Summary

Modifier and Type	Method and Description
static ReplicationConnection.Builder	builder(Configuration jdbcConfig) Creates a new ReplicationConnection.Builder instance which can be used for creating replication connections.
static String	format(long lsn) Formats a LSN long value as a String value which can be used for outputting user-friendly LSN values.
boolean	isConnected() Checks whether this connection is open or not
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 interface java.lang.AutoCloseable

close

Method Detail

startStreaming

ReplicationStream startStreaming()
                          throws SQLException

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

startStreaming

ReplicationStream startStreaming(Long offset)
                          throws SQLException

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

See Also:

LogSequenceNumber

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(Configuration jdbcConfig)

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

Parameters:

jdbcConfig - a Configuration instance that contains JDBC settings; may not be null

Returns:

a builder, never null

format

static String format(long lsn)

Formats a LSN long value as a String value which can be used for outputting user-friendly LSN values.

Parameters:

lsn - the LSN value

Returns:

a String format of the value, never null