MusicBrainz slave server with search and replication

This repo contains everything needed to run a musicbrainz slave server with search and replication in docker.

Table of contents

• Prerequisites
  • Recommended hardware/VM
  • Required software
  • External documentation
• Components version
• Installation
  • Build Docker images
  • Create database
  • Start website
  • Build search indexes
  • Enable replication
  • Enable live indexing
• Advanced configuration
  • Local changes
  • Docker environment variables
  • Docker Compose overrides
• Test setup
• Development setup
• Helper scripts
  • Recreate database
  • Recreate database with indexed search
• Update
• Issues

Prerequisites

Recommended hardware/VM

• CPU: 16 threads (or 2 without indexed search)
• RAM: 16 GB (or 4 without indexed search)
• Disk Space: 150 GB (or 60 without indexed search) + system disk usage

Required software

• Docker Compose 1.21.1 (or higher), see how to install Docker Compose
• Git
• GNU Bash 4 (or higher) utilities, for admin helper scripts only (On macOS, use Homebrew.)
• Linux or macOS (Windows is not documented yet, it is recommended to use Ubuntu via VirtualBox instead.)

If you use Docker Desktop on macOS you may need to increase the amount of memory available to containers from the default of 2GB:

• Preferences > Resources > Memory

If you use Ubuntu 19.10 or later, the above requirements can be set up by running:

sudo apt-get update && \
sudo apt-get install docker.io docker-compose git && \
sudo systemctl enable --now docker.service

If you use UFW to manage your firewall:

• ufw-docker or any other way to fix the Docker and UFW security flaw.

External documentation

• Introduction: Getting started with Docker and Overview of Docker Compose
• Command-line: docker CLI reference and docker-compose CLI reference
• Configuration: Compose file version 3 reference

Components version

• Current MB Branch: v-2021-03-15
• Current DB_SCHEMA_SEQUENCE: 25
• Postgres Version: 12 (can be changed by setting the environment variable POSTGRES_VERSION)
• MB Solr search server: 3.4.1 (can be changed by setting the environment variable MB_SOLR_VERSION)
• Search Index Rebuilder: 1.0.2

Installation

This section is about installing MusicBrainz slave server (mirror) with locally indexed search and automatically replicated data.

Download this repository and change current working directory with:

git clone https://github.com/metabrainz/musicbrainz-docker.git
cd musicbrainz-docker

Build Docker images

Docker images for composed services should be built once using:

sudo docker-compose build

Create database

⚙️ Postgres shared buffers are set to 2GB by default. Before running this step, you should consider modifying your memory settings in order to give your database a sufficient amount of ram, otherwise your database could run very slowly.

Download latest full data dumps and create the database with:

sudo docker-compose run --rm musicbrainz createdb.sh -fetch

Start website

Make the local website available at http://localhost:5000 with:

sudo docker-compose up -d

At this point the local website will show data loaded from the dumps only. For indexed search and replication, keep going!

Build search indexes

Depending on your available ressources in CPU/RAM vs. bandwidth, run:

• Either:

  sudo docker-compose exec indexer python -m sir reindex

  ⚙️ Java heap for Solr is set to 2GB by default. Before running this step, you should consider modifying your memory settings in order to give your search server a sufficient amount of ram, otherwise your search server could run very slowly.

  (This option is known to take 4½ hours with 16 CPU threads and 16 GB RAM.)

• Or, if you have more available bandwidth than CPU/RAM:

  sudo docker-compose run --rm musicbrainz fetch-dump.sh search
  sudo docker-compose run --rm search load-search-indexes.sh

  (This option downloads 28GB of Zstandard-compressed archives from FTP.)

⚠️ Search indexes are not included in replication. You will have to rebuild search indexes regularly to keep it up-to-date.

At this point indexed search works on the local website/webservice. For replication, keep going!

Enable replication

Set replication token

First, copy your MetaBrainz access token (see instructions for generating a token) and paste when prompted to by the following command:

admin/set-replication-token

The token will be written to the file local/secrets/metabrainz_access_token.

Then, grant access to the token for replication with:

admin/configure add replication-token
sudo docker-compose up -d

Run replication once

Run replication script once to catch up with latest database updates:

sudo docker-compose exec musicbrainz replication.sh &
sudo docker-compose exec musicbrainz /usr/bin/tail -f slave.log

Schedule replication

Enable replication as a cron job of root user in musicbrainz service container with:

admin/configure add replication-cron
sudo docker-compose up -d

By default, it replicates data every day at 3 am UTC. To change that, see advanced configuration.

You can view the replication log file while it is running with:

sudo docker-compose exec musicbrainz tail --follow slave.log

You can view the replication log file after it is done with:

sudo docker-compose exec musicbrainz tail slave.log.1

Enable live indexing

⚠️ Search indexes’ live update for slave server is not stable yet. Until then, it should be considered as an experimental feature. Do not use it if you don't want to get your hands dirty.

1. Disable replication cron job if you enabled it:

   admin/configure rm replication-cron
   sudo docker-compose up -d
   

2. Make indexer goes through AMQP Setup with:

   sudo docker-compose exec indexer python -m sir amqp_setup
   admin/create-amqp-extension
   admin/setup-amqp-triggers install

3. Build search indexes either if it has not been built or if it is outdated.

4. Make indexer watch reindex messages with:

   admin/configure add live-indexing-search
   sudo docker-compose up -d

5. Reenable replication cron job if you disabled it at 1.

   admin/configure add replication-cron
   sudo docker-compose up -d
   

Advanced configuration

Local changes

You should preferably not locally change any file being tracked by git. Check your working tree is clean with:

git status

Git is set to ignore the followings you are encouraged to write to:

• .env file,
• any new file under local directory.

Docker environment variables

There are many ways to set environment variables in Docker Compose, the most convenient here is probably to edit the hidden file .env.

You can then check values to be passed to containers using:

sudo docker-compose config

Finally, make Compose picks up configuration changes with:

sudo docker-compose up -d

Customize web server host:port

By default, the web server listens at http://localhost:5000

This can be changed using the two Docker environment variables MUSICBRAINZ_WEB_SERVER_HOST and MUSICBRAINZ_WEB_SERVER_PORT.

If MUSICBRAINZ_WEB_SERVER_PORT set to 80 (http), then the port number will not appear in the base URL of the web server.

If set to 443 (https), then the port number will not appear either, but the a separate reverse proxy is required to handle https correctly.

Customize the number of processes for MusicBrainz Server

By default, MusicBrainz Server uses 10 plackup processes at once.

This number can be changed using the Docker environment variable MUSICBRAINZ_SERVER_PROCESSES.

Customize replication schedule

By default, there is no crontab file in musicbrainz service container.

If you followed the steps to schedule replication, then the crontab file used by musicbrainz service is bound to default/replication.cron.

This can be changed by creating a custom crontab file under local/ directory, and finally setting the Docker environment variable MUSICBRAINZ_CRONTAB_PATH to its path.

Customize search indexer configuration

By default, the configuration file used by indexer service is bound to default/indexer.ini.

This can be changed by creating a custom configuration file under local/ directory, and finally setting the Docker environment variable SIR_CONFIG_PATH to its path.

Docker Compose overrides

In Docker Compose, it is possible to override the base configuration using multiple Compose files.

Some overrides are available under compose directory. Feel free to write your own overrides under local directory.

The helper script admin/configure is able to:

• list available compose files, with a descriptive summary
• show the value of COMPOSE_FILE variable in Docker environment
• set/update COMPOSE_FILE in .env file with a list of compose files
• set/update COMPOSE_FILE in .env file with added or removed compose files

Try admin/configure help for more information.

Publish ports of all services

To publish ports of services db, mq, redis and search (additionally to musicbrainz) on the host, simply run:

admin/configure add publishing-all-ports
sudo docker-compose up -d

Modify memory settings

By default, each of db and search services have about 2GB of RAM. You may want to set more or less memory for any of these services, depending on your available resources or on your priorities.

For example, to set 4GB to each of db and search services, create a file local/compose/memory-settings.yml as follows:

version: '3.1'

# Description: Customize memory settings

services:
  db:
    command: postgres -c "shared_buffers=4GB" -c "shared_preload_libraries=pg_amqp.so"
  search:
    environment:
      - SOLR_HEAP=4g

See postgres for more configuration parameters and options to pass to db service, and solr.in.sh for more environment variables to pass to search service,

Then enable it by running:

admin/configure add local/compose/memory-settings.yml
sudo docker-compose up -d

Test setup

If you just need a small server with sample data to test your own SQL queries and/or MusicBrainz Web Service calls, you can run the below commands instead of following the above installation:

git clone https://github.com/metabrainz/musicbrainz-docker.git
cd musicbrainz-docker
admin/configure add musicbrainz-standalone
sudo docker-compose build
sudo docker-compose run --rm musicbrainz createdb.sh -sample -fetch
sudo docker-compose up -d

The two differences are:

1. sample data dump is downloaded instead of full data dumps,
2. MusicBrainz Server runs in standalone mode instead of slave mode.

Build search indexes and Enable live indexing are the same.

Replication is not applicable to test setup.

Development setup

Required disk space is much lesser than normal setup: 15GB to be safe.

The below sections are optional depending on which service(s) you are coding.

Local development of MusicBrainz Server

For local development of MusicBrainz Server, you can run the below commands instead of following the above installation:

git clone --recursive https://github.com/metabrainz/musicbrainz-server.git
MUSICBRAINZ_SERVER_LOCAL_ROOT=$PWD/musicbrainz-server
git clone https://github.com/metabrainz/musicbrainz-docker.git
cd musicbrainz-docker
echo MUSICBRAINZ_SERVER_LOCAL_ROOT="$MUSICBRAINZ_SERVER_LOCAL_ROOT" >> .env
admin/configure add musicbrainz-dev
sudo docker-compose up -d
sudo docker-compose run --rm musicbrainz createdb.sh -sample -fetch

The four differences are:

1. sample data dump is downloaded instead of full data dumps,
2. MusicBrainz Server runs in standalone mode instead of slave mode,
3. development mode is enabled (but Catalyst debug),
4. MusicBrainz Server code is in musicbrainz-server/ directory.

After changing code in musicbrainz-server/, it can be run as follows:

sudo docker-compose restart musicbrainz

Build search indexes and Enable live indexing are the same.

Replication is not applicable to development setup.

Simply restart the container when checking out a new branch.

Local development of Search Index Rebuilder

This is very similar to the above but for Search Index Rebuilder (SIR):

1. Set the variable SIR_LOCAL_ROOT in the .env file
2. Run admin/configure add sir-dev
3. Run sudo docker-compose up -d

Notes:

• It will override any config.ini file in your local working copy of SIR.
• Requirements are being cached and will be updated on container’s startup.
• See how to configure SIR in musicbrainz-docker.

Local development of MusicBrainz Solr

The situation is quite different for this service as it doesn’t depends on any other. Its development rather rely on schema. See mb-solr and mmd-schema.

However, other services depend on it, so it is useful to run a local version of mb-solr in search service for integration tests:

1. Run build.sh from your mb-solr local working copy to build a an image of metabrainz/mb-solr with a custom tag.
2. Set MB_SOLR_VERSION in .env to this custom tag.
3. Run sudo docker-compose up -d

Helper scripts

There are two directories with helper scripts:

• admin/ contains helper scripts to be run from the host. For more information, use the --help option:

  admin/check-search-indexes --help
  admin/delete-search-indexes --help

  See also:

  • Docker Compose overrides for more information about admin/configure.
  • Enable live indexing for more information about admin/create-amqp-extension and admin/setup-amqp-triggers.
  • Enable replication for more information about admin/set-replication-token.

• build/musicbrainz/scripts/ contains helper scripts to be run from the container attached to the service musicbrainz. Most of these scripts are not for direct use, but createdb.sh and below-documented recreatedb.sh.

Recreate database

If you need to recreate the database, you will need to enter the postgres password set in postgres.env:

• sudo docker-compose run --rm musicbrainz recreatedb.sh

or to fetch new data dumps before recreating the database:

• sudo docker-compose run --rm musicbrainz recreatedb.sh -fetch

Recreate database with indexed search

If you need to recreate the database with indexed search,

admin/configure rm replication-cron # if replication is enabled
sudo docker-compose stop
sudo docker-compose run --rm musicbrainz fetch-dump.sh both
admin/purge-message-queues
sudo docker-compose run --rm search load-search-indexes.sh --force
sudo docker-compose run --rm musicbrainz recreatedb.sh
sudo docker-compose up -d
admin/setup-amqp-triggers clean
admin/setup-amqp-triggers install
admin/configure add replication-cron
sudo docker-compose up -d

you will need to enter the postgres password set in postgres.env:

• sudo docker-compose run --rm musicbrainz recreatedb.sh

or to fetch new data dumps before recreating the database:

• sudo docker-compose run --rm musicbrainz recreatedb.sh -fetch

Update

Check your working tree is clean with:

git status

Check your currently checked out version:

git describe --dirty

Check releases for update instructions.

Issues

If anything doesn't work please create an issue with versions info:

echo MusicBrainz Docker: `git describe --always --broken --dirty --tags` && \
echo Docker Compose: `docker-compose version --short` && \
sudo docker version -f 'Docker Client/Server: {{.Client.Version}}/{{.Server.Version}}'