BindingFilter

StreamFlow lets users map steps to multiple targets. A BindingFilter object implements a strategy to manipulate and reorder the list of targets bound to a given step before the StreamFlow Scheduler component evaluates them. The BindingFilter interface specified in the streamflow.core.deployment module contains a single get_targets method:

async def get_targets(
    self, job: Job, targets: MutableSequence[Target]
) -> MutableSequence[Target]:
    ...

The get_targets method receives a Job object and a list of Target objects, the list of targets specified by the user, and returns another list of Target objects. The Scheduler component will evaluate the returned list of targets to find an allocation for the Job object.

By default, if no BindingFilter is specified for a multi-target step binding, all the Target objects will be evaluated in the original order. In addition, StreamFlow defines a ShuffleBindingFilter implementation to randomise the evaluation order at any invocation.

Implementations

Type	Class
shuffle	streamflow.deployment.filter.shuffle.ShuffleBindingFilter