[SEJeff]

How do you power cron from ZK? Do you use something like airbnb's chronos[1]?

[1] http://nerds.airbnb.com/introducing-chronos

[maplebed]

No, I took a different approach. Any normal cron job that wants to be run only once (per cluster) grabs a zookeeper lock. Those that fail to acquire the lock exit and try again during the next interval. This is implemented with a wrapper around the cron job that takes care of locking: https://github.com/ParsePlatform/Ops/blob/master/tools/get_z.... More details here: http://blog.parse.com/2013/03/11/implementing-failover-for-r...