Minecraft Prometheus Exporter

A Bukkit plugin to exports Minecraft server metrics to Prometheus.

Built for Paper, Spigot, Bukkit, Folia (experimental) and other forks.

If you're running multiple Minecraft servers behind a BungeeCord proxy, you might also be interested in Bungeecord Prometheus Exporter for additional metrics!

Quick Start

Copy the prometheus-exporter.jar into your Bukkit plugins directory and start your Minecraft server.

After startup, the Prometheus metrics endpoint should be available at localhost:9940/metrics (assuming localhost is the server hostname).

The metrics port can be customized in the plugin's config.yml (a default config will be created after the first use).

Feature Overview

Prometheus Exporter

The plugin exports a variety of metrics about your Minecraft server to Prometheus. These metrics can be used to monitor the health and performance of your server.

The metrics are exposed at localhost:9940/metrics by default. See the rest of the README for more information on how to configure Prometheus to scrape these metrics.

Custom Health Checks

The plugin can be configured to perform custom health checks on your server. These checks can be used to monitor the health of your server and alert you if something goes wrong.

The aggregated health checks are exposed at localhost:9940/health by default.

See Health Checks for more information on how to build your own health checks in your plugins.

Installation & Configuration

Plugin config

The default configuration file will be created after the first use of the plugin.

# Note that the HTTP server binds to localhost by default.
# If your Prometheus runs on another host or inside a Kubernetes cluster
# set this to any reachable IP or 0.0.0.0 to listen on all interfaces.
host: localhost
# The port can be changed in case it conflicts with any other application.
port: 9940
# Metrics can be enabled individually. Metrics which are disabled
# by default may have a performance impact on your server.
# See the rest of the README for more information.
enable_metrics:
  jvm_threads: true
  jvm_gc: true
  players_total: true
  whitelisted_players: true
  entities_total: true
  living_entities_total: true
  loaded_chunks_total: true
  jvm_memory: true
  players_online_total: true
  tps: true
  tick_duration_average: true
  tick_duration_median: true
  tick_duration_min: false
  tick_duration_max: true
  player_online: false
  player_statistic: false

Prometheus config

Add the following job to the scrape_configs section of your Prometheus configuration:

Single server

- job_name: 'minecraft'
  static_configs:
    - targets: ['localhost:9940']
      labels:
        server_name: 'my-awesome-server'

Multiple servers

You can use labels in your Prometheus scrape configuration to distinguish between multiple servers:

- job_name: 'minecraft'
  static_configs:
    - targets: ['localhost:9940']
      labels:
        server_name: 'server1'
    - targets: ['localhost:9939']
      labels:
        server_name: 'server2'

Import Grafana Dashboard

1. Navigate to Grafana -> Dashboards -> Import
2. Paste in or upload minecraft-server-dashboard.json
3. Update "JVM Memory Used" to reflect your server max memory (Default 8G)
4. Edit (bottom right widget) -> Options -> Gauage -> Max

You can also build your own dashboards using the metrics exported by the plugin. See available metrics for a list of all the metrics exported by the plugin.

Available metrics

The following metrics are exported by the plugin:

Label	Description	Folia Support
mc_players_total	Unique players on server (online + offline)	✅
mc_whitelisted_players	Players count on the white list	❌
mc_loaded_chunks_total	Chunks loaded per world	❌
mc_players_online_total	Online players per world	✅
mc_entities_total	Entities loaded per world (living + non-living)	❌
mc_villagers_total	Villagers	❌
mc_world_size	World size in bytes	✅
mc_jvm_memory	JVM memory usage	✅
mc_jvm_threads	JVM threads info	✅
mc_tps	Server tickrate (TPS)	❌
mc_tick_duration_median	Median Tick Duration (ns, usually last 100 ticks)	❌
mc_tick_duration_average	Average Tick Duration (ns, usually last 100 ticks)	❌
mc_tick_duration_min	Min Tick Duration (ns, usually last 100 ticks)	❌
mc_tick_duration_max	Max Tick Duration (ns, usually last 100 ticks)	❌

Player metrics

Warning

The following feature is against Prometheus best-practices and is not recommended for production servers.

There is an option to export per-player statistics like the number of blocks mined, mobs killed, items used, etc. The amount of data stored in Prometheus can dramatically increase when this is enabled as individual time-series will be generated for each player that has ever been seen on the server. The statistic collection may also have an impact on the Minecraft server performance for bigger servers but it has not been measured or tested.

On the other hand this should be quite safe for small private servers with limited players.

You can enable the experimental player export in the config.yaml.

enable_metrics:
  player_online: true
  player_statistic: true

This will enable the additional metrics.

Label	Description	Folia
mc_player_statistic	Player statistics	❌
mc_player_online	Online state by player name	❌

There's an additional sample Grafana dashboard with player statistics enabled to get you started.

You can find the full list here. Use the "Resource location" for the metrics label with removing the "minecraft:" part and converted to uppercase. This doesn't support all statistics in the list because they are provided by the upstream Spigot libraries.

Compatibility

Plugin version	Min Minecraft version	Min Java version
3.x.x	1.17.1	17
1.0.0 - 2.x.x	1.11.x	11

Notes

• Java 17 is required for the latest version of the plugin.
• There is a known issue with Azul JVM.
• There is currently rudimentary support for Folia servers. Only selected metrics are supported.
• The plugin has been tested recently on
  • Minecraft 1.20.1
  • Minecraft 1.20.4

Plugin Integration

By integrating your own plugin with the Minecraft Prometheus Exporter, you can:

1. Monitor your plugin's performance: Collect metrics about your plugin's performance and resource usage.
2. Provide custom health checks: Monitor the health of your plugin and alert you if something goes wrong.

Collect metrics about your own plugin

You can easily collect metrics about your own plugin.

Include the Prometheus dependency

<dependency>
    <groupId>io.prometheus</groupId>
    <artifactId>simpleclient_common</artifactId>
    <version>...</version>
</dependency>

Collect metrics

This pseudocode shows how you would count invocations of a plugin command.

public class MyPluginCommand extends PluginCommand {

  // Register your counter
  private Counter commandCounter = Counter.build()
            .name("mc_my_plugin_command_invocations_total")
            .help("Counter for my plugin command invocations")
            .register();

  @Override
  public boolean execute(CommandSender sender, String commandLabel, String[] args) {

    // Increment your counter;
    commandCounter.inc();

    // Do other stuff

    return true;
  }

}

Provide a health check from your own plugin

You can easily collect metrics about your own plugin.

Add compile-time dependency to your plugin

1. Get the latest minecraft-prometheus-exporter-3.0.0.jar from the releases page.
2. Add the jar to your project's classpath.

Create a health check

Create your custom health check by extending the HealthCheck class.

public class CustomHealthCheck implements HealthCheck {
    @Override
    public boolean isHealthy() {
        return true; // Your custom health check logic
    }
}

Register the health check

Register your health check in your plugin's onEnable method or similar.

This will add your health check to the list of health checks that are aggregated and exposed by the Minecraft Prometheus Exporter

public class MyPlugin extends JavaPlugin {

    @Override
    public void onEnable() {
      // Register your health check
      getServer().servicesManager.load(HealthChecks.class).add(new CustomHealthCheck());
    }
}