Cronken is a Redis-backed distributed cron system which allows running cronjobs across a set of servers without risking double-running them on multiple boxes at once. To facilitate this, it uses Redis locks to ensure that only one server at a time runs any particular job. It also uses Redis for all of its input and output, reading its job list from Redis, storing results to Redis, and subscribing to a Redis pub/sub channel to allow for centralized control of all cronken instances.
A barebones example using a local Redis server can be found in example_server.py, and a slightly more sophisticated example that uses aiohttp to expose a web interface can be found in example_web.py.
A full description of the backend Redis data format can be found in cronken_specification.md.