This is a pre-production deployment of Warehouse. Changes made here affect the production instance of PyPI (
Help us improve Python packaging - Donate today!
Project Description

BeatCop is a simple cluster singleton manager. It ensures that a managed process runs on exactly one node in a cluster at a time, no more, no less (assuming there is at least one node left alive).

It was created for managing Celery beat in an autoscaling pool of Celery workers but was written as generic process manager and can therefore be used for pretty much anything. It uses Redis to communicate.


BeatCop uses an expiring Redis key (SET EX NX) as a lock, which it continually refreshes while the controlled process is running. If the BeatCop or the whole node dies for any reason, drops off the network or loses connection to Redis, the lock expires and a waiting BeatCop on another node will then acquire the lock and launch a new process.

The lock is acquired (via SET NX) and refreshed (via a short LUA script) atomically, so there should be no race conditions.

BeatCop also tries very hard to make sure that if anything goes wrong, the monitored process is stopped.


  • A server running Redis 2.6.12 or higher to which all nodes can connect.


# Make a virtualenv if you like first
pip install -r requirements.txt
./ /path/to/beatcop.ini

It is typically a good idea to run BeatCop in something that will restart it if it dies, such as daemon-tools or the dreaded Upstart.


See example beatcop.ini.


BeatCop relies on Redis connectivity. If Redis updates fail, BeatCop will stop the controlled process and exit, hoping that at least one other node can still talk to Redis and spawn a new process. If all nodes lose Redis connectivity, this will obviously fail. BeatCop now supports Redis Cluster (see example beatcop.ini), which means Redis no longer has to be the single point of failure.

BeatCop does not currently work via nutcracker (twemproxy).


MIT - see LICENSE file.

Release History

Release History


This version

History Node

TODO: Figure out how to actually get changelog content.

Changelog content for this version goes here.

Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur. Donec ut libero sed arcu vehicula ultricies a non tortor. Lorem ipsum dolor sit amet, consectetur adipiscing elit.

Show More

Download Files

Download Files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

File Name & Checksum SHA256 Checksum Help Version File Type Upload Date
BeatCop-1.0.tar.gz (5.5 kB) Copy SHA256 Checksum SHA256 Source Jun 24, 2016

Supported By

WebFaction WebFaction Technical Writing Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Rackspace Rackspace Cloud Servers DreamHost DreamHost Log Hosting