The scheduler has the concept of an algorithm provider and an algorithm. Together, they let you use the substantial functionality of the built-in scheduler in order to replace the core scheduling algorithm.
The algorithm provider lets you register new algorithm providers with the factory. There is already one custom provider registered, called ClusterAutoScalerProvider. We will see later how the scheduler knows which algorithm provider to use. The key file is as follows:
The init() function calls the registerAlgorithmProvider(), which you should extend to include your algorithm provider in addition to the default and autoscaler providers:
func registerAlgorithmProvider(predSet, priSet sets.String) {
// Registers algorithm providers. By default we use 'DefaultProvider'
// but user can specify one to be used by specifying flag.
factory.RegisterAlgorithmProvider(factory.DefaultProvider, predSet, priSet)
// Cluster autoscaler friendly scheduling algorithm.
factory.RegisterAlgorithmProvider(ClusterAutoscalerProvider, predSet,
copyAndReplace(priSet, "LeastRequestedPriority", "MostRequestedPriority"))
}
In addition to registering the provider, you also need to register a fit predicate and a priority function, which are used to actually perform the scheduling.
You can use the factory's RegisterFitPredicate() and RegisterPriorityFunction2() functions.