[minimax]

I don't think it's uncommon at all to roll your own job scheduler. I know I've done it at the last two places I have worked, though neither had nearly as fancy a front-end as Chronos appears to have. This particular scheduler (Chronos) looks like a cross between traditional cron and HPC cluster job scheduling systems (a la Sun Grid Engine). It looks like a really cool project.

[tptacek]

That depends on what you mean by job scheduling, right? Lots of people would call Resque a job scheduling system, but they still reach for cron when they want to run something every 5 minutes.

[minimax]

I'm about as unaware of the Ruby ecosystem as anyone who regularly reads HN can be, so while I've heard of Resque I'm not really sure where it fits in.

I suppose the definition of job scheduling is dependent on what your workload entails. Is it something you expect to complete in less than a second, a minute, or a big resource intensive HPC job you expect to run for hours? What sorts of dependencies do you have between the things you want to run? Will it run in the main event loop, separate thread, separate process, or on a separate host? I think this will reflect in the tool you choose for scheduling, or cause you to write your own.

It sounds to me like the target workload for Chronos is big slow batch jobs (ETL, data analysis). HPC job schedulers take care of things like resource management (run this job on this machine because it has the lowest load) and dependency management (don't run job b until job a completes), whereas cron handles running periodic tasks and that's about it. Chronos is nice because it looks like it is combining the two and includes a nice looking web based control panel to boot.