feat: update default scheduler to priority for agentrm (#9385)

docs/reference/deploy/master-config-reference.rst

@@ -284,7 +284,7 @@ behavior specified here. For more on scheduling behavior in Determined, see :ref
 ^^^^^^^^
 
    The scheduling policy to use when allocating resources between different tasks (experiments,
-   notebooks, etc.). Defaults to ``fair_share``.
+   notebooks, etc.). Defaults to ``priority``.
 
    -  ``fair_share``: Tasks receive a proportional amount of the available resources depending on
       the resource they require and their weight.

docs/release-notes/feature-clean-up.rst

@@ -8,13 +8,18 @@ out-of-the-box with minimal customization required.
 
 Agent Resource Manager:
 
--  Container Runtimes: We will limit support to Docker for Agent Resource Managers.
+-  Container Runtimes: Due to limited usage, we will limit supported container runtimes to Docker
+   for the Agent Resource Manager. This does not impact Kubernetes, Slurm or PBS environments.
 
--  Job Scheduling: Moving a job will require adjusting its priority; jobs cannot be shifted within
-   the same priority group. Support for round-robin and fair share schedulers is discontinued. We
-   recommend using the priority scheduler, as it meets most scheduling needs and simplifies
-   configuration.
+-  Job Scheduling: The default scheduler is now ``priority``. Support for round-robin and fair share
+   schedulers has been discontinued. We recommend using the priority scheduler, as it meets most
+   scheduling needs and simplifies configuration. To move a job, you will need to adjust its
+   priority; jobs cannot be shifted within the same priority group.
 
--  AMD GPUs: Support will continue only for Nvidia GPUs.
+-  AMD GPUs: Due to limited usage, we will limit supported accelerators to NVIDIA GPUs. If you have
+   a use case requiring AMD GPU support with the Agent Resource Manager, please reach out to us via
+   a `GitHub Issue <https://github.com/determined-ai/determined/issues>`__ or `community slack
+   <https://join.slack.com/t/determined-community/shared_invite/zt-1f4hj60z5-JMHb~wSr2xksLZVBN61g_Q>`__!
+   This does not impact Kubernetes or Slurm environments.
 
 Machine Architectures: PPC64/POWER builds across all environments are no longer supported.

master/cmd/determined-master/root.go

@@ -193,18 +193,21 @@ func applyBackwardsCompatibility(configMap map[string]interface{}) (map[string]i
 	vProvisioner, provisionerExisted := configMap["provisioner"]
 
 	// Ensure we use either the old schema or the new one.
-	if (rmExisted || rpsExisted) && (schedulerExisted || provisionerExisted) {
+	oldRMConfig := schedulerExisted || provisionerExisted
+	newRMConfig := rmExisted || rpsExisted
+	if newRMConfig && oldRMConfig {
 		return nil, errors.New(
 			"cannot use the old and the new configuration schema at the same time",
 		)
 	}
-	if rmExisted || rpsExisted {
+	if !oldRMConfig {
+		// Use configMap if RMs are not defined at all, or if they are defined using the new schema.
 		return configMap, nil
 	}
 
 	// If use the old schema, convert it to the new one.
 	newScheduler := map[string]interface{}{
-		"type":           "fair_share",
+		"type":           "priority",
 		"fitting_policy": "best",
 	}
 	newRM := map[string]interface{}{

master/cmd/determined-master/root_test.go

@@ -147,7 +147,7 @@ func TestApplyBackwardsCompatibility(t *testing.T) {
 					"type": "agent",
 					"scheduler": map[string]interface{}{
 						"fitting_policy": "best",
-						"type":           "fair_share",
+						"type":           "priority",
 					},
 					"default_cpu_resource_pool": "default",
 					"default_gpu_resource_pool": "default",
@@ -178,7 +178,7 @@ func TestApplyBackwardsCompatibility(t *testing.T) {
 					"type": "kubernetes",
 					"scheduler": map[string]interface{}{
 						"fitting_policy": "best",
-						"type":           "fair_share",
+						"type":           "priority",
 					},
 					"master_service_name": "k8s-det",
 				},

master/internal/config/scheduler_config.go

@@ -26,8 +26,12 @@ const (
 
 // DefaultSchedulerConfig returns the default fair share configuration for the scheduler.
 func DefaultSchedulerConfig() *SchedulerConfig {
+	tmp := DefaultSchedulingPriority
 	return &SchedulerConfig{
-		FairShare:     &FairShareSchedulerConfig{},
+		Priority: &PrioritySchedulerConfig{
+			Preemption:      false,
+			DefaultPriority: &tmp,
+		},
 		FittingPolicy: defaultFitPolicy,
 	}
 }