Prepare Database
================

Backend.AI makes use of PostgreSQL as the main database to store user information, access control policies, and persistent states of the system such as agent and container tracking registry.
Launch the service using docker compose by generating the file ``$HOME/halfstack/postgres-cluster-default/docker-compose.yaml`` and populating it with the following YAML.
Feel free to adjust the volume paths and port settings.
Please refer `the latest configuration <https://github.com/lablup/backend.ai/blob/main/docker-compose.halfstack-main.yml>`_
(it's a symbolic link so follow the filename in it) if needed.

.. code-block:: yaml

   x-base: &base
      logging:
         driver: "json-file"
         options:
            max-file: "5"
            max-size: "10m"

   services:
      backendai-half-db:
         <<: *base
         image: postgres:16.3-alpine
         container_name: backendai-halfstack-db
         restart: unless-stopped
         command: >
            postgres
            -c "max_connections=256"
            -c "max_worker_processes=4"
            -c "deadlock_timeout=10s"
            -c "lock_timeout=60000"
            -c "idle_in_transaction_session_timeout=60000"
         environment:
            - POSTGRES_USER=postgres
            - POSTGRES_PASSWORD=develove
            - POSTGRES_DB=backend
            - POSTGRES_INITDB_ARGS="--data-checksums"
         healthcheck:
            test: ["CMD", "pg_isready", "-U", "postgres"]
            interval: 10s
            timeout: 3s
            retries: 10
         volumes:
            - "${HOME}/.data/backend.ai/postgres-data/active:/var/lib/postgresql/data:rw"
         ports:
            - "8100:5432"
         networks:
            half_stack:
         cpu_count: 4
         mem_limit: "4g"

   networks:
       half_stack:

Execute the following command to start the service container.
The project ``${USER}`` is added for operational convenience.

.. code-block:: console

   $ cd ${HOME}/halfstack/postgres-cluster-default
   $ docker compose up -d
   $ # -- To terminate the container:
   $ # docker compose down
   $ # -- To see the container logs:
   $ # docker compose logs -f