Prometheus/Dogstatsd compatible, minimalistic monitoring agent

Gent is a simple application telemetry collector & exporter. It Ingests both regular StatsD and its extended variant, DogStatsD messages and generates Prometheus-compatible telemetry. It is designed to be reasonably small with no external dependencies. It can be built with nothing beyond Go standard library.

Gent is intended to be run on the host or inside a container with direct host networking. For maximal usefulness, it is distributed under the MIT license.

Download: gent.tar.xz (~10kB)

Using Gent

Once the agent is running, send *StatsD messages to its listening port. Gent will process the messages and generate an export for Prometheus-compatible scrapers. These exports are regenerated every 15 seconds.

Basic Architecture

  | HOST |
+-------------------------------------------------------+
|                                                       |
| +---------------+               +---------------+     |
| |  Service A    |-+           +-|+-------------+|     |
| +---------------+ |           | || Container X ||     |
|                   |[msg]      | |+-------------+|     |
| +---------------+ |[msg]      | +---------------+     |
| |  Service B    |-+      [msg]|                       |
| +---------------+ |           |                       |
|                   |[msg] [msg]|                       |
|                   |      [msg]|                       |
|                   |      [msg]|                       |
|                   |[msg]      |            +------+   |
|                   v           v            | Gent |   |
|                                            |      |   |
+-------------------Y-----------Y------------========---+
               localhost      container-network

Performance

Tested on a relatively recent AMD Zen 7 @3.3GHz.

With the included stresser sources, gent can sustain a degenerate rate of 400k packets per second before dropping packages. At rates below 50k/pps the CPU utilisation is negligible.

Miscellania

The name gent is a pun, for "a gent".

It is inspired by bucky3, a monitoring agent used internally at Smarkets .

The ringbuffer design is inspired by LMAX Disruptor but takes a few shortcuts to make the implementation easier to reason about.

For practical information on DogStatsD message format, see this article.