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Currently in Numaflow, there are 3 CRDs introduced, each one has a corresponding controller.


The source code of the controllers is located at ./pkg/reconciler/.


Inter-Step Buffer Service Controller

Inter-Step Buffer Service Controller is used to watch InterStepBufferService object, depending on the spec of the object, it might install services (such as JetStream, or Redis) in the namespace, or simply provide the configuration of the InterStepBufferService (for example, when an external redis ISB Service is given).

Pipeline Controller

Pipeline Controller is used to watch Pipeline objects, it does following major things when there's a pipeline object created.

  • Spawn a Kubernetes Job to create buffers and buckets in the Inter-Step Buffer Services.
  • Create Vertex objects according to .spec.vertices defined in Pipeline object.
  • Create some other Kubernetes objects used for the Pipeline, such as a Deployment and a Service for daemon service application.

Vertex Controller

Vertex controller watches the Vertex objects, based on the replica defined in the spec, creates a number of pods to run the workloads.