Open Source Job Scheduler with REST API

ProActive Scheduler is an open source job scheduler.

• It is part of OW2 organization
• It is written in Java so it comes with a Java and a REST API
• It provides workflows that are set of tasks with dependencies and more (loop,replicate, branch), upon failures you can control if the task should be cancelled or restarted
• Parallelism and distribution is at the heart of it, with features like for instance

Commercial Support is provided by Activeeon, the company behind ProActive (full disclosure: I work for Activeeon).

JobScheduler would seem to meet your requirements:

• Open Source see: Open Source and Commercial Licenses
• Rest API see: Web Service Integration
• Parallelism see: Organisation of Jobs and Job Chains

I think that these areas are also covered (I downloaded and trialled the application): See here

• Tree like Job dependency
• Hold & Release
• Rerun failed steps

I'm not affiliated with SOS GmbH

You might be interested in DKron

Dkron is a system service that runs scheduled jobs at given intervals or times, just like the cron unix service but distributed in several machines in a cluster. If a machine fails (the leader), a follower will take over and keep running the scheduled jobs without human intervention. Dkron is Open Source and freely available.

http://dkron.io/