Metrics

The dashboard shows the slowest queue (highest average runtime) and the busiest one (most jobs processed) of the last hour. The metrics page shows, per job class and per queue, over the last hour to the last seven days:

• the jobs processed and failed, the failure rate, the average wait;
• the average, p95, p99 and maximum runtime: p95 is the time under which 95 % of the jobs ran, a better view of what your users wait for than the average;
• the trend of the throughput, the failure rate and the runtime compared with the previous period of the same length (a failure rate or a runtime going up is shown in red);
• a heatmap of the jobs per hour over the last seven days, in your timezone, the hours where 10 % or more of the jobs failed outlined: spot the peaks and the nightly batches at a glance.

Each job and queue also has its history of snapshots, stored every five minutes by meridian:snapshot.

Prometheus and OpenTelemetry

Meridian exposes its metrics in the Prometheus text format at /meridian/prometheus, for Prometheus, Grafana Alloy, the OpenTelemetry Collector (prometheus receiver), Datadog (OpenMetrics check) or Victoria Metrics. Enable it and give your scraper a token:

MERIDIAN_PROMETHEUS=true
MERIDIAN_PROMETHEUS_TOKEN=a-long-random-token

scrape_configs:
  - job_name: meridian
    metrics_path: /meridian/prometheus
    authorization:
      credentials: a-long-random-token
    static_configs:
      - targets: ['app.example.com']

Without a token, the dashboard authorization applies (enough in local). The metrics are gauges, labelled by connection and queue or by task:

Metric	Description
meridian_up	1 running, 0.5 paused, 0 inactive
meridian_queue_pending_jobs, _delayed_jobs, _reserved_jobs	Jobs of each queue
meridian_queue_wait_seconds, meridian_queue_processes	Wait of the oldest job, worker processes
meridian_queue_jobs_processed_last_hour, _failed_last_hour	Throughput and failures of the last hour
meridian_queue_runtime_avg_seconds, _max_seconds	Runtime of the jobs of the last hour
meridian_jobs_per_minute, meridian_jobs_processing	Overall throughput, running jobs
meridian_failed_jobs, meridian_error_groups	Failed jobs (7 days) and distinct errors
meridian_workers, meridian_supervisors	Live processes by status
meridian_schedule_task_healthy, _last_run_timestamp_seconds, _last_runtime_seconds	Health and last run of each scheduled task

meridian_schedule_task_last_run_timestamp_seconds lets your monitoring warn you when the scheduler itself stops, which Meridian cannot do from within it.