Bitnami Postgresql synchronous commit test setup

README.md

startup:

docker-compose up

psql in each a node, if desired (nodes are pg-source, pg-replica1, and pg-replica2):

docker exec -it pg-source bash -c 'PGPASSWORD=my_password psql -U my_user -d my_database -P pager=off -P expanded=auto'

read replication log sequence number (LSN) position:

select pg_last_wal_replay_lsn();

parse the return value in Go:

func lsnToInt64(lsn string) (int64, error) {
	var pos int64
	parts := strings.Split(lsn, "/")
	for _, part := range parts {
		val, err := strconv.ParseInt(part, 16, 64)
		if err != nil {
			return 0, err
		}
		pos = pos + val
	}
	return pos, nil
}

docker-compose.yml

version: '2'

services:
  postgresql-source:
    image: 'bitnami/postgresql:latest'
    container_name: pg-source
    ports:
      - '5432'
    volumes:
      - './postgresql_source_data:/bitnami/postgresql'
    environment:
      - POSTGRESQL_REPLICATION_MODE=master
      - POSTGRESQL_REPLICATION_USER=repl_user
      - POSTGRESQL_REPLICATION_PASSWORD=repl_password
      - POSTGRESQL_USERNAME=my_user
      - POSTGRESQL_PASSWORD=my_password
      - POSTGRESQL_DATABASE=my_database
      - POSTGRESQL_SYNCHRONOUS_COMMIT_MODE=on
      - POSTGRESQL_NUM_SYNCHRONOUS_REPLICAS=1
  postgresql-replica1:
    image: 'bitnami/postgresql:latest'
    container_name: pg-replica1
    ports:
      - '5433'
    depends_on:
      - postgresql-source
    environment:
      - POSTGRESQL_REPLICATION_MODE=slave
      - POSTGRESQL_REPLICATION_USER=repl_user
      - POSTGRESQL_REPLICATION_PASSWORD=repl_password
      - POSTGRESQL_MASTER_HOST=postgresql-source
      - POSTGRESQL_MASTER_PORT_NUMBER=5432
      - ALLOW_EMPTY_PASSWORD=yes
    volumes:
      - './postgresql_replica1_data:/bitnami/postgresql'
  postgresql-replica2:
    image: 'bitnami/postgresql:latest'
    container_name: pg-replica2
    ports:
      - '5434'
    depends_on:
      - postgresql-source
    environment:
      - POSTGRESQL_REPLICATION_MODE=slave
      - POSTGRESQL_REPLICATION_USER=repl_user
      - POSTGRESQL_REPLICATION_PASSWORD=repl_password
      - POSTGRESQL_MASTER_HOST=postgresql-source
      - POSTGRESQL_MASTER_PORT_NUMBER=5432
      - ALLOW_EMPTY_PASSWORD=yes
    volumes:
      - './postgresql_replica2_data:/bitnami/postgresql'