Which of the following components are involved in Nova scheduling in OpenStack?

This question is best treated as a multiple-correct-answer item, because official OpenStack documentation shows that Nova-Scheduler and Placement are both directly involved in the scheduling workflow. The Nova scheduling reference explains that the scheduler receives a request specification and then sends the requirements to Placement , which determines the resource providers capable of satisfying the request. Placement returns candidate resource information, and Nova-Scheduler performs filtering, weighing, and final host selection.

OpenStack documentation also notes that the nova-scheduler and placement services are responsible for tracking resources and deciding which compute node instances should be on . That makes A and D the directly scheduling-related components. While Nova-Conductor and Nova-API participate in the broader instance build flow by receiving requests and coordinating actions, they are not the core components that actually perform the scheduling decision itself.

So, for strict technical accuracy based on official OpenStack architecture, the verified answer is A and D . If your exam system forces only one option, then A (Nova-Scheduler) is the closest single best answer, but the documentation supports A and D together.

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