A replication architecture database is a valuable approach for separating read and write responsibilities into different database servers. This allows for efficient scaling of the database based on the type of operations or transactions that occur. In this guide, we will set up a replication architecture database in a Docker environment using Docker Compose, specifically for our development environment.
Technologies Used
- PostgreSQL
- Docker Compose
Getting Started
- Install Docker Desktop
Docker Compose Setup
Begin by creating a docker-compose.yaml
file to define the services, configurations, and dependencies for the PostgreSQL replication setup.
version: "3"
services:
postgresql-master:
image: bitnami/postgresql
restart: always
ports:
- '5432:5432'
volumes:
- postgresql_master_data:/bitnami/postgresql
- ./db.sql:/docker-entrypoint-initdb.d/db.sql
environment:
- POSTGRESQL_PGAUDIT_LOG=READ,WRITE
- POSTGRESQL_LOG_HOSTNAME=true
- POSTGRESQL_REPLICATION_MODE=master
- POSTGRESQL_REPLICATION_USER=repl_user
- POSTGRESQL_REPLICATION_PASSWORD=repl_user
- POSTGRESQL_USERNAME=postgres
- POSTGRESQL_PASSWORD=postgres
- POSTGRESQL_DATABASE=development_database
- ALLOW_EMPTY_PASSWORD=yes
postgresql-slave:
image: bitnami/postgresql
restart: always
ports:
- '5432'
depends_on:
- postgresql-master
environment:
- POSTGRESQL_PASSWORD=postgres
- POSTGRESQL_MASTER_HOST=postgresql-master
- POSTGRESQL_PGAUDIT_LOG=READ
- POSTGRESQL_LOG_HOSTNAME=true
- POSTGRESQL_REPLICATION_MODE=slave
- POSTGRESQL_REPLICATION_USER=repl_user
- POSTGRESQL_REPLICATION_PASSWORD=repl_user
- POSTGRESQL_MASTER_PORT_NUMBER=5432
- ALLOW_EMPTY_PASSWORD=yes
volumes:
postgresql_master_data:
driver: local
This docker-compose.yaml
file defines two services: postgresql-master
and postgresql-slave
. The postgresql-master
service acts as the master node, while the postgresql-slave
service acts as the slave node.
Explanation of Key Configurations
- PostgreSQL Master Service:
POSTGRESQL_REPLICATION_MODE=master
: Specifies that this PostgreSQL instance is the master.POSTGRESQL_REPLICATION_USER
andPOSTGRESQL_REPLICATION_PASSWORD
: Credentials for replication.POSTGRESQL_DATABASE
: Name of the development database.POSTGRESQL_PGAUDIT_LOG=READ,WRITE
: Enables audit logging for read and write operations.
- PostgreSQL Slave Service:
POSTGRESQL_REPLICATION_MODE=slave
: Specifies that this PostgreSQL instance is the slave.POSTGRESQL_MASTER_HOST
: Points to the host of the master node.POSTGRESQL_MASTER_PORT_NUMBER
: Port number on which the master node is running.POSTGRESQL_PGAUDIT_LOG=READ
: Enables audit logging for read operations.
Running the Setup
To start the PostgreSQL replication setup, navigate to the directory containing the docker-compose.yaml
file and run:
docker-compose up -d
This will launch the services in detached mode. You can then access the master and slave databases separately, and any changes made in the master will be replicated to the slave.
This Docker-Compose setup provides a convenient way to implement PostgreSQL database replication for your development environment. Adjust the configurations based on your specific requirements and scaling needs.