zookeeper-healthcheck

A simple healthcheck wrapper to monitor ZooKeeper.

ZooKeeper Healthcheck is a simple server that provides a singular API endpoint to determine the health of a ZooKeeper instance. This can be used to alert or take action on unhealthy ZooKeeper instances.

The service checks the health by sending netcat commands as well as checking that ZooKeeper is in a desired mode. It utilizes the commands echo ruok | nc zookeeper-host zookeeper-port and echo stat | nc zookeeper-host zookeeper-port | grep Mode to do so.

By default, the root endpoint / will return 200 OK healthy if ZooKeeper responds imok and is in mode leader or follower. It will return 503 Service Unavailable if ZooKeeper does not respond with imok or if its in an undesired mode (by default standalone).

Usage

ZooKeeper Healthcheck can be installed via pip. Both python and pip are required, as well as echo, nc and grep.

Command-Line

Install zookeeper-healthcheck via pip:

pip install zookeeper-healthcheck

To start the healthcheck server, run:

zookeeper-healthcheck

The server will now be running on localhost:12181.

Configuration

ZooKeeper Healthcheck can be configured via command-line arguments or by environment variables.

Port

The port for the zookeeper-healthcheck API.

ZooKeeper Host

The host of the ZooKeeper instance to run the health check against. This is used with nc.

ZooKeeper Port

The port of the ZooKeeper instance to run the health check against. This is used with nc.

Healthy Modes

A comma-separated list of ZooKeeper modes to be marked as healthy. Any modes not in this list will mark ZooKeeper as unhealthy.

Log Level

The level of logs to be shown by the application.

All healthy responses are logged at INFO. Unhealthy responses are logged at WARNING. Any unexpected errors are logged at ERROR.

License

Copyright (c) 2019 Shawn Seymour.

Licensed under the Apache 2.0 license.