Docker (Mac or Linux)¶
This section describes setting up a Citus cluster on a single machine using docker-compose.
The Docker image is intended for development/testing purposes only, and has not been prepared for production use. The images use default connection settings, which are very permissive, and not suitable for any kind of production setup. These should be updated before using the image for production use. The PostgreSQL manual explains how to make them more restrictive.
1. Install Docker Community Edition and Docker Compose
- Install Docker.
- Start Docker by clicking on the application’s icon.
curl -sSL https://get.docker.com/ | sh sudo usermod -aG docker $USER && exec sg docker newgrp `id -gn` sudo systemctl start docker sudo curl -sSL https://github.com/docker/compose/releases/download/1.16.1/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose sudo chmod +x /usr/local/bin/docker-compose
The above version of Docker Compose is sufficient for running Citus, or you can install the latest version.
2. Start the Citus Cluster
Citus uses Docker Compose to run and connect containers holding the database coordinator node, workers, and a persistent data volume. To create a local cluster download our Docker Compose configuration file and run it
curl -L https://raw.githubusercontent.com/citusdata/docker/master/docker-compose.yml > docker-compose.yml COMPOSE_PROJECT_NAME=citus docker-compose up -d
The first time you start the cluster it builds its containers. Subsequent startups take a matter of seconds.
If you already have PostgreSQL running on your machine you may encounter this error when starting the Docker containers:
Error starting userland proxy: Bind for 0.0.0.0:5432: unexpected error address already in use
This is because the “master” (coordinator) service attempts to bind to the standard PostgreSQL port 5432. Simply choose a different port for coordinator service with the
MASTER_EXTERNAL_PORT environment variable. For example:
MASTER_EXTERNAL_PORT=5433 COMPOSE_PROJECT_NAME=citus docker-compose up -d
3. Verify that installation has succeeded
To verify that the installation has succeeded we check that the coordinator node has picked up the desired worker configuration. First start the psql shell on the coordinator (master) node:
docker exec -it citus_master psql -U postgres
Then run this query:
SELECT * FROM master_get_active_worker_nodes();
You should see a row for each worker node including the node name and port.
4. Shut down the cluster when ready
When you wish to stop the docker containers, use Docker Compose:
COMPOSE_PROJECT_NAME=citus docker-compose down -v