psql.replication — net.clojars.savya/psql-clj 2.4.0

PostgreSQL streaming replication over pgjdbc: log sequence numbers (LSNs), replication-slot management, and logical decoding streams.

A replication connection is a special connection opened with the replication property set; replication-spec adds the required properties to a db spec. The server must run with wal_level = logical (and enough max_wal_senders / max_replication_slots) for logical replication.

close-stream! clj

(close-stream! stream)

Close a replication STREAM.

create-logical-slot! clj

(create-logical-slot! conn slot-name plugin)

Create a logical replication SLOT-NAME using output PLUGIN (for example "pgoutput" or "test_decoding"). Returns a slot-info map with :slot-name, :replication-type, :consistent-point, :snapshot-name, and :output-plugin.

create-physical-slot! clj

(create-physical-slot! conn slot-name)

Create a physical replication SLOT-NAME. Returns a slot-info map.

drop-slot! clj

(drop-slot! conn slot-name)

Drop the replication slot SLOT-NAME.

force-status-update! clj

(force-status-update! stream)

Send a standby status update to the server immediately.

last-received-lsn clj

(last-received-lsn stream)

The last LSN received on STREAM.

lsn clj

(lsn x)

Coerce X to a pgjdbc LogSequenceNumber. X is an LSN string like "16/B374D848", a long, or an existing LogSequenceNumber.

lsn->long clj

(lsn->long l)

Return the 64-bit long value of an LSN.

lsn->string clj

(lsn->string l)

Return the canonical X/Y string form of an LSN.

read-change clj

(read-change stream)

Read the next change from STREAM as a java.nio.ByteBuffer, blocking until one is available.

read-pending clj

(read-pending stream)

Read the next available change from STREAM as a java.nio.ByteBuffer, or nil if none is pending right now (non-blocking).

replication-api clj

(replication-api conn)

Return pgjdbc's PGReplicationConnection for a connection opened from a replication-spec.

replication-spec clj

(replication-spec spec)

Return SPEC with the properties pgjdbc needs to open a replication connection: :replication "database", simple query mode, and a minimum server version. Pass the result to next.jdbc/get-connection.

set-applied-lsn! clj

(set-applied-lsn! stream l)

Tell the server STREAM has applied up to L (an LSN).

set-flushed-lsn! clj

(set-flushed-lsn! stream l)

Tell the server STREAM has durably flushed up to L (an LSN).

start-logical-replication clj

(start-logical-replication conn
                           {:keys [slot-name start-lsn status-interval-ms
                                   slot-options]})

Start a logical decoding stream on an existing logical slot and return a pgjdbc PGReplicationStream. OPTS keys:

• :slot-name (required) the logical slot to stream from
• :start-lsn start position (LSN string/long/LogSequenceNumber)
• :status-interval-ms standby status update interval
• :slot-options a map of output-plugin option name to string value

Consume it with read-pending/read, acknowledge progress with set-flushed-lsn!/set-applied-lsn!, and close-stream! when done.