---
title: Monitor Telegraf Controller
description: Monitor the health of a Telegraf Controller server using its unauthenticated health endpoints and its log output.
url: https://docs.influxdata.com/telegraf/controller/admin/monitor/
estimated_tokens: 669
publisher: InfluxData
canonical: https://docs.influxdata.com/telegraf/controller/admin/monitor/
date: '2026-09-23T16:27:16-06:00'
lastmod: '2026-09-23T16:27:16-06:00'
---

Monitor a Telegraf Controller server with its built-in health endpoints and
its log output.

* [Health endpoints](#health-endpoints)
* [Server logs](#server-logs)
* [What to watch for](#what-to-watch-for)

## Health endpoints

Telegraf Controller exposes unauthenticated HTTP health endpoints on the
API port and on the heartbeat port.`GET /health/live` and `GET /health/ready` on the API port are the
general-purpose liveness and readiness probes, and the heartbeat service
answers `GET /health` on its own port.`GET /health/leader` identifies the leader in a[high-availability cluster](/telegraf/controller/admin/high-availability/).

For the full endpoint reference, including status codes, response bodies,
and how to choose a probe, see[Health endpoints](/telegraf/controller/admin/high-availability/load-balancing/#health-endpoints).
The endpoints are documented with load balancers in mind, but any monitoring
system can poll them.

## Server logs

Telegraf Controller writes log output to the console (standard output and
standard error).
Where that output ends up depends on how you run the server:

* **Interactive terminal**: log output appears in the terminal.
* **systemd**: the journal captures console output.
  Read it with `journalctl -u telegraf-controller`.
* **LaunchDaemon (macOS)**: output goes to the file paths configured in the
  service plist.
  The[LaunchDaemon example](/telegraf/controller/admin/run-as-a-service/#macos-launchdaemon)uses `/var/log/telegraf-controller.log`.
* **Windows service**: configure your service manager to capture console
  output to files.
  See[Run Telegraf Controller as a service](/telegraf/controller/admin/run-as-a-service/#windows-nssm).

## What to watch for

Alert on the following log messages.
Each entry links to the page that explains how to fix the problem.

* **Database errors**, such as `database is locked`,`database or disk is full`, or `database disk image is malformed`.
  See [Troubleshoot the database](/telegraf/controller/admin/troubleshoot/database/).
* **Rejected agent heartbeats**, which return HTTP `401` with an invalid token error.
  See [Agent heartbeats return 401 Invalid token](/telegraf/controller/admin/troubleshoot/agents/#agent-heartbeats-return-401-invalid-token).
* **License errors**.
  See [Troubleshoot licensing](/telegraf/controller/telegraf-enterprise/troubleshoot/).

#### Related

* [Configure a load balancer for high availability](/telegraf/controller/admin/high-availability/load-balancing/)
* [Troubleshoot the database](/telegraf/controller/admin/troubleshoot/database/)
* [Troubleshoot agent heartbeats and tokens](/telegraf/controller/admin/troubleshoot/agents/)