fredlock - Redis RedLock based distributed locking tool

fredlock distributed locking utility

fredlock is a distributed locking tool based on Redis RedLock algorithm intended as a replacement for "flock" command line utility, it allows to run commands on multiple machines with a guarantee that no two instances will be running at the same time.

fredlock requires a shared Redis instance to provide locking

Release Notes

• 0.1.3 - No Changes (testing auto-release)

• 0.1.2 - No Changes (testing auto-release)

• 0.1.1 - Bugfixes

  • Removed --redis_ssl and --redis-unix-socket-path command line options for now, not compatible with older redis clients
  • Fixed sleep after acquire/before release

• 0.1.0 - Initial version

  • Features
    • Auto-release of a lock after x seconds if command does not complete in allotted time. (--auto-release-time x)
    • Specify how long to wait for lock
      • Indefinitely (--wait-timeout -1)
      • Limited Time (--wait-timeout x (x > 0))
      • Do not wait (--wait-timeout 0)
    • Custom Optional Delays:
      • After lock acquire, before command execution (--delay-after-acquire x)
      • After command execution, before lock release ( --delay-before-release x)

TODOs:

Some other ideas/desired features:

• Quiet timeouts (no output/failure if not run due to timeout trying to get lock)
• Config file (currently we support cli and env variables)
• Redis Cluster support
• Lock Namespacing

Installation

From PyPi:

pip install fredlock

Usage

Full build-in usage is available with --help flag.

Run command with automatically-generated name lock

Simplest usage to run a command command arg1 arg2 with lock command:

fredlock run command arg1 arg2

Run command with a specified name lock

Simplest usage to run a command command arg1 arg2 with lock lockname:

fredlock --name lockname run command arg1 arg2