Target Execution Ordering

When executing a job, Flowman normally figures out the correct execution order of all targets automatically. This is implemented by looking at the different targets inputs and outputs, such that Flowman ensures that first all the inputs of a target is build before the target itself is executed.

Cyclic Dependencies

But sometimes, this does not give you the desired result, or Flowman might even detect a cyclic dependency between your targets. Although this might indicate an issue at the conceptional level, there are completely valid use cases where apparently cyclic dependencies are not an actual problem. But Flowman would still refuse to execute a job with cyclic dependencies in its default configuration.

Manual Scheduler

To overcome issues with a wrong (or unsolvable) execution order, Flowman provides a mechanism to turn off the automatic execution ordering. This is achieved by setting the following configuration variable

  - flowman.execution.scheduler.class=com.dimajix.flowman.execution.ManualScheduler

This setting will replace the usual dependency scheduler by a manual scheduler, where all targets are executed precisely in the order as specified within a job. This also implies that when using the ManualScheduler, the developer is both in complete control of execution order but also fully responsible for a correct execution order.