Prometheus Metrics

Dagu exposes Prometheus metrics for monitoring workflow execution, system health, and operational insights. These metrics can be scraped by Prometheus and visualized in tools like Grafana.

Endpoint

Metrics are available at:

GET /api/v2/metrics

Access Control

By default, the metrics endpoint requires authentication. You can configure public access if needed.

Configuration

Config file (~/.config/dagu/config.yaml):

yaml

# Require authentication (default)
metrics: "private"

# Allow public access (no authentication required)
metrics: "public"

Environment variable:

bash

export DAGU_SERVER_METRICS=public

Available Metrics

System Metrics

Metric	Type	Description
`dagu_info`	Gauge	Build information (version, go_version labels)
`dagu_uptime_seconds`	Gauge	Time since server start
`dagu_scheduler_running`	Gauge	Whether the scheduler is running (1) or not (0)
`dagu_dags_total`	Gauge	Total number of DAGs

Aggregate DAG Run Metrics

These metrics provide system-wide totals across all DAGs:

Metric	Type	Labels	Description
`dagu_dag_runs_currently_running`	Gauge	-	Total number of currently running DAG runs
`dagu_dag_runs_queued_total`	Gauge	-	Total number of DAG runs in queue
`dagu_dag_runs_total`	Counter	`status`	Total DAG runs by status (today)

Status values: succeeded, failed, aborted, running, queued, not_started, partially_succeeded

Per-DAG Metrics

These metrics provide granular visibility into individual DAG performance:

Metric	Type	Labels	Description
`dagu_dag_runs_currently_running_by_dag`	Gauge	`dag`	Running count per DAG
`dagu_dag_runs_queued_by_dag`	Gauge	`dag`	Queue depth per DAG
`dagu_dag_runs_total_by_dag`	Counter	`dag`, `status`	DAG runs by DAG and status (today)
`dagu_dag_run_duration_seconds`	Histogram	`dag`	Duration of completed DAG runs
`dagu_queue_wait_seconds`	Histogram	`dag`	Time spent waiting in queue

Histogram Buckets

DAG Run Duration (dagu_dag_run_duration_seconds):

Buckets: 1s, 5s, 15s, 30s, 60s, 120s, 300s, 600s, 1800s, 3600s
Designed for workflow-appropriate timescales

Queue Wait Time (dagu_queue_wait_seconds):

Buckets: 1s, 5s, 10s, 30s, 60s, 120s, 300s, 600s
Shorter timescales for queue latency monitoring

Cache Metrics

Dagu exposes internal cache statistics for memory monitoring and debugging:

Metric	Type	Labels	Description
`dagu_cache_entries_total`	Gauge	`cache`	Number of entries in each cache

Cache names: dag_definition, dag_run_status, api_key, webhook

Cache limits are configurable via the cache setting:

yaml

cache: normal   # options: low, normal, high (default: normal)

Or via environment variable: DAGU_CACHE=low

Preset values:

Preset	DAG	DAGRun	APIKey	Webhook
low	500	5,000	100	100
normal	1,000	10,000	500	500
high	5,000	50,000	1,000	1,000

TTL: DAG/DAGRun=12h, APIKey/Webhook=15m

These metrics help identify memory growth issues by tracking cache sizes over time.

Go Runtime Metrics

Standard Go runtime metrics are also exposed:

go_goroutines - Number of goroutines
go_memstats_* - Memory statistics
go_gc_* - Garbage collection metrics
process_* - Process-level metrics

Prometheus Configuration

Private Mode (Default)

When metrics: "private", configure Prometheus to authenticate:

Using API Token:

yaml

scrape_configs:
  - job_name: 'dagu'
    bearer_token: 'your-api-token'
    static_configs:
      - targets: ['dagu:8080']
    metrics_path: '/api/v2/metrics'

Using Basic Auth:

yaml

scrape_configs:
  - job_name: 'dagu'
    basic_auth:
      username: 'admin'
      password: 'secret'
    static_configs:
      - targets: ['dagu:8080']
    metrics_path: '/api/v2/metrics'

Public Mode

When metrics: "public", no authentication is needed:

yaml

scrape_configs:
  - job_name: 'dagu'
    static_configs:
      - targets: ['dagu:8080']
    metrics_path: '/api/v2/metrics'

Example Queries

DAG Success Rate (Today)

promql

sum(dagu_dag_runs_total{status="succeeded"}) /
sum(dagu_dag_runs_total) * 100

Per-DAG Success Rate

promql

sum by (dag) (dagu_dag_runs_total_by_dag{status="succeeded"}) /
sum by (dag) (dagu_dag_runs_total_by_dag) * 100

Average DAG Duration (Per DAG)

promql

sum by (dag) (rate(dagu_dag_run_duration_seconds_sum[1h])) /
sum by (dag) (rate(dagu_dag_run_duration_seconds_count[1h]))

Average DAG Duration (Overall)

promql

sum(rate(dagu_dag_run_duration_seconds_sum[1h])) /
sum(rate(dagu_dag_run_duration_seconds_count[1h]))

95th Percentile Duration (Per DAG)

promql

histogram_quantile(0.95,
  sum by (dag, le) (rate(dagu_dag_run_duration_seconds_bucket[1h]))
)

95th Percentile Duration (Overall)

promql

histogram_quantile(0.95,
  sum by (le) (rate(dagu_dag_run_duration_seconds_bucket[1h]))
)

Queue Depth Over Time

promql

dagu_dag_runs_queued_total

Currently Running DAGs

promql

dagu_dag_runs_currently_running

Slowest DAGs (P95 Duration)

promql

topk(10,
  histogram_quantile(0.95,
    sum by (dag, le) (rate(dagu_dag_run_duration_seconds_bucket[24h]))
  )
)

Cache Size Monitoring

promql

dagu_cache_entries_total

Cache Growth Rate

promql

rate(dagu_cache_entries_total[1h])

Grafana Dashboard

You can create a Grafana dashboard with panels for:

Overview Panel
- Total DAGs
- Running DAGs
- Queued DAGs
- Scheduler status
Success/Failure Panel
- DAG runs by status (pie chart)
- Success rate over time (graph)
Performance Panel
- DAG duration histogram
- P50, P95, P99 duration trends
- Queue wait time distribution
Per-DAG Details
- Table of DAGs with run counts, success rates, avg duration
- Individual DAG duration trends

Sample Dashboard JSON

json

{
  "title": "Dagu Workflow Metrics",
  "panels": [
    {
      "title": "Running DAGs",
      "type": "stat",
      "targets": [{"expr": "dagu_dag_runs_currently_running"}]
    },
    {
      "title": "Queue Depth",
      "type": "stat",
      "targets": [{"expr": "dagu_dag_runs_queued_total"}]
    },
    {
      "title": "DAG Runs by Status",
      "type": "piechart",
      "targets": [{"expr": "sum by (status) (dagu_dag_runs_total)"}]
    }
  ]
}

Alerting Examples

High Failure Rate

yaml

groups:
  - name: dagu
    rules:
      - alert: DaguHighFailureRate
        expr: |
          sum(rate(dagu_dag_runs_total{status="failed"}[1h])) /
          sum(rate(dagu_dag_runs_total[1h])) > 0.1
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High DAG failure rate"
          description: "More than 10% of DAG runs are failing"

Long Queue Wait

yaml

      - alert: DaguLongQueueWait
        expr: |
          histogram_quantile(0.95,
            sum by (le) (rate(dagu_queue_wait_seconds_bucket[15m]))
          ) > 300
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "Long queue wait times"
          description: "P95 queue wait time exceeds 5 minutes"

Scheduler Down

yaml

      - alert: DaguSchedulerDown
        expr: dagu_scheduler_running == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "Dagu scheduler is not running"

Cache Size Growing

yaml

      - alert: DaguCacheGrowing
        expr: dagu_cache_entries_total > 10000
        for: 30m
        labels:
          severity: warning
        annotations:
          summary: "Cache size is large"
          description: "Cache {{ $labels.cache }} has {{ $value }} entries"

Workers

Prometheus Metrics

Endpoint

Access Control

Configuration

Available Metrics

System Metrics

Aggregate DAG Run Metrics

Per-DAG Metrics

Histogram Buckets

Cache Metrics

Go Runtime Metrics

Prometheus Configuration

Private Mode (Default)

Public Mode

Example Queries

DAG Success Rate (Today)

Per-DAG Success Rate

Average DAG Duration (Per DAG)

Average DAG Duration (Overall)

95th Percentile Duration (Per DAG)

95th Percentile Duration (Overall)

Queue Depth Over Time

Currently Running DAGs

Slowest DAGs (P95 Duration)

Cache Size Monitoring

Cache Growth Rate

Grafana Dashboard

Sample Dashboard JSON

Alerting Examples

High Failure Rate

Long Queue Wait

Scheduler Down

Cache Size Growing

See Also

Prometheus Metrics ​

Endpoint ​

Access Control ​

Configuration ​

Available Metrics ​

System Metrics ​

Aggregate DAG Run Metrics ​

Per-DAG Metrics ​

Histogram Buckets ​

Cache Metrics ​

Go Runtime Metrics ​

Prometheus Configuration ​

Private Mode (Default) ​

Public Mode ​

Example Queries ​

DAG Success Rate (Today) ​

Per-DAG Success Rate ​

Average DAG Duration (Per DAG) ​

Average DAG Duration (Overall) ​

95th Percentile Duration (Per DAG) ​

95th Percentile Duration (Overall) ​

Queue Depth Over Time ​

Currently Running DAGs ​

Slowest DAGs (P95 Duration) ​

Cache Size Monitoring ​

Cache Growth Rate ​

Grafana Dashboard ​

Sample Dashboard JSON ​

Alerting Examples ​

High Failure Rate ​

Long Queue Wait ​

Scheduler Down ​

Cache Size Growing ​

See Also ​

Prometheus Metrics

Endpoint

Access Control

Configuration

Available Metrics

System Metrics

Aggregate DAG Run Metrics

Per-DAG Metrics

Histogram Buckets

Cache Metrics

Go Runtime Metrics

Prometheus Configuration

Private Mode (Default)

Public Mode

Example Queries

DAG Success Rate (Today)

Per-DAG Success Rate

Average DAG Duration (Per DAG)

Average DAG Duration (Overall)

95th Percentile Duration (Per DAG)

95th Percentile Duration (Overall)

Queue Depth Over Time

Currently Running DAGs

Slowest DAGs (P95 Duration)

Cache Size Monitoring

Cache Growth Rate

Grafana Dashboard

Sample Dashboard JSON

Alerting Examples

High Failure Rate

Long Queue Wait

Scheduler Down

Cache Size Growing

See Also