How to Efficiently Monitor HAProxy with Prometheus and Grafana

In today's fast‑moving internet era, users expect high availability and fast response from online services, and operators must keep websites and applications running 24/7. HAProxy is a popular load‑balancer, but effective monitoring is essential for its health.

Enable HAProxy Monitoring

Deploy a Prometheus exporter on HAProxy by adding a frontend that listens on port 8405 and exposes the /metrics endpoint.

frontend prometheus
  bind *:8405
  mode http
  http-request use-service prometheus-exporter if { path /metrics }
  no log

Tip: Restart the HAProxy service after making configuration changes.

Prometheus Collects HAProxy Metrics

Edit the Prometheus ConfigMap to add a job named haproxy with the HAProxy instances as static targets.

$ kubectl -n kube-system edit cm prometheus
- job_name: 'haproxy'
  static_configs:
  - targets:
    - "172.139.20.3:8405"
    - "172.139.20.92:8405"

Verify that metrics are being collected with a curl query to the Prometheus API:

$ curl -u admin -s $(kubectl -n kube-system get svc prometheus -ojsonpath='{.spec.clusterIP}:{.spec.ports[0].port}')/prometheus/api/v1/query --data-urlencode 'query=up{job=~"haproxy"}' | jq '.data.result[]'

Add HAProxy Dashboard to Grafana

Import dashboard ID 12693 in Grafana to visualize HAProxy metrics.

Conclusion

By building a comprehensive HAProxy monitoring system, you can detect and resolve potential issues early and obtain data to optimize performance. Monitoring is a continuous process that must be regularly refined to keep services stable and deliver the best user experience.