Postgres Logical Replication

Overview

This is a POC to test out Postgres streaming logical replication in Rust using rust-postgres.

It requires:

• a running postgres database server.
• wal2json plugin should be installed.
• ensure wal_level config is set to 'logical' (ALTER SYSTEM SET wal_level = logical;)

This example shows how to:

• create a publication
• create a replication slot
• read protocol messages
• read json encoded WAL updates

Currently, the example only replicates insert statements on the given table. To try it run the following command with your db config:

DB_CONF="user=postgres password=password host=localhost port=5432 dbname=postgres" TABLE_NAME=<your-table-name> cargo run

It will start replicating every insert transactions on the source database as they arrive by following the Postgres Replication protocol. As soon as receives a new transaction, it replays it in an embeded duckdb database.

This POC uses Materialize's fork of rust-postgres for logical replication protocol implementation.

Helpful links

• Logical decoding example
• Replication issue on rust-postgres repo
• Materialize's fork of rust-postgres with the patches required to support logical decoding
• Replication example
• Instructure's Change data capture