Observability with Prometheus

You can export metrics in Prometheus format from your Metabase.

Running Metabase and Prometheus locally

To give you an idea of how Metabase and Prometheus would work in your production environment, we’ll walk through how to set up Metabase and Prometheus locally.

Start up Metabase with `MB_PROMETHEUS_SERVER_PORT`

Download the latest Metabase JAR, and run Metabase using an environment variable to specify the Prometheus server port:

MB_PROMETHEUS_SERVER_PORT=9191 java -jar metabase.jar

The MB_PROMETHEUS_SERVER_PORT=9191 specifies which port (9191) Metabase will use to send data to Prometheus. To clarify the ports that will be involved here:

Port 3000 is the port Metabase uses to serve the Metabase app. You can set another port with MB_JETTY_PORT (e.g., MB_JETTY_PORT=3001).
- Port 9191 (or whichever port you specified with the MB_PROMETHEUS_SERVER_PORT environment variable) is the port Prometheus uses to scrape metrics from Metabase.
Port 9090 is the port Prometheus uses to serve the Prometheus application.

When you start Metabase, the Metabase logs will tell you that Metabase is starting the prometheus metrics collector and prometheus metrics web-server.

(truncated logs)
2022-09-01 17:47:38,808 INFO metabase.util :: Database setup took 3.4 s
2022-09-01 17:47:38,826 INFO metabase.core :: Setting up prometheus metrics
2022-09-01 17:47:38,827 INFO metabase.prometheus :: Starting prometheus metrics collector
2022-09-01 17:47:38,839 INFO metabase.prometheus :: Starting prometheus metrics web-server on port 9,191
(truncated logs)

You can view your locally running Metabase at http://localhost:3000.

Download and configure Prometheus

Download Prometheus, and extract the files.

Change into the Prometheus directory, add the following YAML file to configure your Prometheus:

Prometheus configuration file example

global:
  scrape_interval:     15s # By default, scrape targets every 15 seconds.

  # Attach these labels to any time series or alerts when communicating with
  # external systems (federation, remote storage, Alertmanager).
  external_labels:
    monitor: 'codelab-monitor'

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'

    # Override the global default and scrape targets from this job every 5 seconds.
    scrape_interval: 5s
    # use whatever port here that you set for MB_PROMETHEUS_SERVER_PORT
    static_configs:
      - targets: ['localhost:9191']

Running Prometheus Locally

In a new terminal process in the Prometheus directory, run:

./prometheus --config.file=prometheus.yml

Then check http://localhost:9090. You should see the Prometheus app, and be able to search for various metrics emitted by Metabase.

Prometheus page showing `jvm_thread_state` graph

Sample metrics output

Here is some sample output from Metabase:

'# HELP jvm_threads_current Current thread count of a JVM
'# TYPE jvm_threads_current gauge
jvm_threads_current 81.0
'# HELP jvm_threads_daemon Daemon thread count of a JVM
'# TYPE jvm_threads_daemon gauge
jvm_threads_daemon 36.0
'# HELP jvm_threads_peak Peak thread count of a JVM
'# TYPE jvm_threads_peak gauge
jvm_threads_peak 81.0
'# HELP jvm_threads_started_total Started thread count of a JVM
'# TYPE jvm_threads_started_total counter
jvm_threads_started_total 104.0
'# HELP jvm_threads_deadlocked Cycles of JVM-threads that are in deadlock waiting to acquire object monitors or ownable synchronizers
'# TYPE jvm_threads_deadlocked gauge
jvm_threads_deadlocked 0.0

Exported metrics

Metrics exported by Metabase include:

c3p0_max_pool_size
c3p0_min_pool_size
c3p0_num_busy_connections
c3p0_num_connections
c3p0_num_idle_connections
c3p0_num_threads_awaiting_checkout_default_user
jetty_async_dispatches_total
jetty_async_requests_total
jetty_async_requests_waiting
jetty_async_requests_waiting_max
jetty_dispatched_active
jetty_dispatched_active_max
jetty_dispatched_time_max
jetty_dispatched_time_seconds_total
jetty_dispatched_total
jetty_expires_total
jetty_request_time_max_seconds
jetty_request_time_seconds_total
jetty_requests_active
jetty_requests_active_max
jetty_requests_total
jetty_responses_bytes_total
jetty_responses_total
jetty_stats_seconds
jvm_gc_collection_seconds_count
jvm_gc_collection_seconds_sum
jvm_memory_bytes_committed
jvm_memory_bytes_init
jvm_memory_bytes_max
jvm_memory_bytes_used
jvm_memory_objects_pending_finalization
jvm_memory_pool_bytes_committed
jvm_memory_pool_bytes_init
jvm_memory_pool_bytes_max
jvm_memory_pool_bytes_used
jvm_memory_pool_collection_committed_bytes
jvm_memory_pool_collection_init_bytes
jvm_memory_pool_collection_max_bytes
jvm_memory_pool_collection_used_bytes
jvm_threads_current
jvm_threads_daemon
jvm_threads_deadlocked
jvm_threads_deadlocked_monitor
jvm_threads_peak
jvm_threads_started_total
jvm_threads_state
process_cpu_seconds_total
process_max_fds
process_open_fds
process_start_time_seconds