Zend

I'm looking for a way to manage asynchronous, potentially long-running PHP jobs (ex. feed import and generation). One could start with a simple cron-based system, but this has a few drawbacks :

* Too much 'downtime' if you set the sample interval too long
* Overlapping jobs if jobs don't finish
* No ability to handle events or dependency issues

I've previously used AppWorx (appworx.com) in a large ETL operation. AppWorx is quite sophisticated with a distributed slave architecture, chains, forks and joins. But AppWorx is probably too complex for my needs.