HAProxy

Overview

The OpenTelemetry Collector's HAProxy receiver polls HAProxy periodically through either a Unix domain socket or an HTTP stats URL, collecting metrics about frontends, backends, and server health. The collector then forwards these metrics to Dash0.

Prerequisites

Before setting up HAProxy monitoring, ensure:

• HAProxy 2.0 or later is running and accessible
• HAProxy's stats interface is enabled (socket or HTTP — see below)
• OpenTelemetry Collector is deployed using the OpenTelemetry Collector Contrib distribution

You'll need an OpenTelemetry Collector deployed in your environment. Consider using:

• OpenTelemetry Operator for Kubernetes

• Helm Chart for The OpenTelemetry Collector

Enable HAProxy Stats

The receiver requires HAProxy's stats interface to be enabled. Choose one of the following approaches:

Option A: Unix Socket (recommended for non-Kubernetes)

Add the following to the global section of your haproxy.cfg:

Option B: HTTP Stats Page (recommended for Kubernetes)

Add a dedicated stats frontend to your haproxy.cfg:

Restart HAProxy after making configuration changes:

Collector Configuration

Add the HAProxy receiver to your OpenTelemetry Collector configuration:

Wire the receiver into a pipeline:

Configuration Options

• endpoint (required): Path to the HAProxy stats interface. Use file:// prefix for a Unix socket or a full HTTP URL for the stats page.
• collection_interval: How often to poll HAProxy for metrics. Default: 1m.
• initial_delay: Delay before the first collection. Default: 1s.
• metrics: Optionally enable or disable individual metrics. All 17 default metrics are enabled automatically.

For all available options, see the HAProxy receiver documentation.

Kubernetes: Mounting the Stats Socket

If using a Unix socket in Kubernetes, mount the socket path as a hostPath volume in your collector DaemonSet:

For most Kubernetes setups, the HTTP stats page approach (Option B) is simpler.

Verification

1. Check the collector logs for successful connections to HAProxy
2. Navigate to the Metrics Explorer in Dash0
3. Search for metrics with the prefix haproxy.*
4. Confirm key metrics are visible:
   • haproxy.requests.total — cumulative request count per backend
   • haproxy.sessions.count — current active sessions
   • haproxy.connections.rate — new connections per second
   • haproxy.bytes.input / haproxy.bytes.output — traffic throughput
   • haproxy.responses.errors — backend error responses

References

• OpenTelemetry HAProxy Receiver Documentation
• HAProxy Configuration Manual
• HAProxy Management Guide — Stats Socket