fix: [Flow Control]: Cleanup: Remove PriorityName from PriorityBandConfig

pkg/epp/flowcontrol/contracts/registry.go

@@ -219,9 +219,6 @@ type ShardStats struct {
 type PriorityBandStats struct {
 	// Priority is the numerical priority level this struct describes.
 	Priority int
-	// PriorityName is a human-readable name for the priority band (e.g., "Critical", "Sheddable").
-	// The registry configuration requires this field, so it is guaranteed to be non-empty.
-	PriorityName string
 	// CapacityBytes is the configured maximum total byte size for this priority band.
 	// When viewed via `AggregateStats`, this is the global limit. When viewed via `ShardStats`, this is the partitioned
 	// value for that specific shard.

pkg/epp/flowcontrol/controller/internal/processor.go

@@ -230,19 +230,11 @@ func (sp *ShardProcessor) enqueue(item *FlowItem) {
 		return
 	}
 
-	band, err := sp.shard.PriorityBandAccessor(key.Priority)
-	if err != nil {
-		finalErr := fmt.Errorf("configuration error: failed to get priority band for priority %d: %w", key.Priority, err)
-		sp.logger.Error(finalErr, "Rejecting item.", "flowKey", key, "reqID", req.ID())
-		item.FinalizeWithOutcome(types.QueueOutcomeRejectedOther, fmt.Errorf("%w: %w", types.ErrRejected, finalErr))
-		return
-	}
-
 	// --- Capacity Check ---
 	// This check is safe because it is performed by the single-writer Run goroutine.
 	if !sp.hasCapacity(key.Priority, req.ByteSize()) {
 		sp.logger.V(logutil.DEBUG).Info("Rejecting request, queue at capacity",
-			"flowKey", key, "reqID", req.ID(), "priorityName", band.PriorityName(), "reqByteSize", req.ByteSize())
+			"flowKey", key, "reqID", req.ID(), "priority", key.Priority, "reqByteSize", req.ByteSize())
 		item.FinalizeWithOutcome(types.QueueOutcomeRejectedCapacity, fmt.Errorf("%w: %w",
 			types.ErrRejected, types.ErrQueueAtCapacity))
 		return
@@ -253,12 +245,12 @@ func (sp *ShardProcessor) enqueue(item *FlowItem) {
 	if err := managedQ.Add(item); err != nil {
 		finalErr := fmt.Errorf("failed to add item to queue for flow key %s: %w", key, err)
 		sp.logger.Error(finalErr, "Rejecting item post-admission.",
-			"flowKey", key, "reqID", req.ID(), "priorityName", band.PriorityName())
+			"flowKey", key, "reqID", req.ID(), "priority", key.Priority)
 		item.FinalizeWithOutcome(types.QueueOutcomeRejectedOther, fmt.Errorf("%w: %w", types.ErrRejected, finalErr))
 		return
 	}
 	sp.logger.V(logutil.TRACE).Info("Item enqueued.",
-		"flowKey", key, "reqID", req.ID(), "priorityName", band.PriorityName())
+		"flowKey", key, "reqID", req.ID(), "priority", key.Priority)
 }
 
 // hasCapacity checks if the shard and the specific priority band have enough capacity.
@@ -301,7 +293,7 @@ func (sp *ShardProcessor) dispatchCycle(ctx context.Context) bool {
 		item, err := sp.selectItem(ctx, originalBand)
 		if err != nil {
 			sp.logger.Error(err, "Failed to select item, skipping priority band for this cycle",
-				"priority", priority, "priorityName", originalBand.PriorityName())
+				"priority", priority)
 			continue // Continue to the next band to maximize work conservation.
 		}
 		if item == nil {
@@ -313,7 +305,7 @@ func (sp *ShardProcessor) dispatchCycle(ctx context.Context) bool {
 		candidates := sp.podLocator.Locate(ctx, req.GetMetadata())
 		if sp.saturationDetector.IsSaturated(ctx, candidates) {
 			sp.logger.V(logutil.DEBUG).Info("Policy's chosen item is saturated; enforcing HoL blocking.",
-				"flowKey", req.FlowKey(), "reqID", req.ID(), "priorityName", originalBand.PriorityName())
+				"flowKey", req.FlowKey(), "reqID", req.ID(), "priority", priority)
 			// Stop the dispatch cycle entirely to respect strict policy decision and prevent priority inversion where
 			// lower-priority work might exacerbate the saturation affecting high-priority work.
 			return false
@@ -322,7 +314,7 @@ func (sp *ShardProcessor) dispatchCycle(ctx context.Context) bool {
 		// --- Dispatch ---
 		if err := sp.dispatchItem(item); err != nil {
 			sp.logger.Error(err, "Failed to dispatch item, skipping priority band for this cycle",
-				"flowKey", req.FlowKey(), "reqID", req.ID(), "priorityName", originalBand.PriorityName())
+				"flowKey", req.FlowKey(), "reqID", req.ID(), "priority", priority)
 			continue // Continue to the next band to maximize work conservation.
 		}
 		return true
@@ -483,7 +475,7 @@ func (sp *ShardProcessor) processAllQueuesConcurrently(
 	for _, priority := range sp.shard.AllOrderedPriorityLevels() {
 		band, err := sp.shard.PriorityBandAccessor(priority)
 		if err != nil {
-			logger.Error(err, "Failed to get PriorityBandAccessor", "priority", priority)
+			logger.Error(err, "Failed to get PriorityBandAccessor, skipping band", "priority", priority)
 			continue
 		}
 		band.IterateQueues(func(queue framework.FlowQueueAccessor) bool {

pkg/epp/flowcontrol/controller/internal/processor_test.go

@@ -592,19 +592,7 @@ func TestShardProcessor(t *testing.T) {
 						assert.ErrorIs(t, item.FinalState().Err, testErr, "The underlying error should be preserved")
 					},
 				},
-				{
-					name: "should reject item on registry priority band lookup failure",
-					setupHarness: func(h *testHarness) {
-						h.addQueue(testFlow)
-						h.PriorityBandAccessorFunc = func(int) (framework.PriorityBandAccessor, error) { return nil, testErr }
-					},
-					assert: func(t *testing.T, h *testHarness, item *FlowItem) {
-						assert.Equal(t, types.QueueOutcomeRejectedOther, item.FinalState().Outcome,
-							"Outcome should be RejectedOther")
-						require.Error(t, item.FinalState().Err, "An error should be returned")
-						assert.ErrorIs(t, item.FinalState().Err, testErr, "The underlying error should be preserved")
-					},
-				},
+
 				{
 					name: "should reject item on queue add failure",
 					setupHarness: func(h *testHarness) {

pkg/epp/flowcontrol/framework/accessors.go

@@ -55,9 +55,6 @@ type PriorityBandAccessor interface {
 	// Priority returns the numerical priority level of this group.
 	Priority() int
 
-	// PriorityName returns the human-readable name of this priority band.
-	PriorityName() string
-
 	// FlowKeys returns the list of identities for every flow currently active within this group.
 	// The caller can use the ID field from each key to look up a specific queue via the Queue(id) method.
 	// The order of keys is not guaranteed unless specified by the implementation.

pkg/epp/flowcontrol/framework/mocks/mocks.go

@@ -72,16 +72,14 @@ var _ framework.FlowQueueAccessor = &MockFlowQueueAccessor{}
 // This avoids collision with the interface method of the same name.
 type MockPriorityBandAccessor struct {
 	PriorityV         int
-	PriorityNameV     string
 	PolicyStateV      any
 	FlowKeysFunc      func() []types.FlowKey
 	QueueFunc         func(flowID string) framework.FlowQueueAccessor
 	IterateQueuesFunc func(callback func(flow framework.FlowQueueAccessor) (keepIterating bool))
 }
 
-func (m *MockPriorityBandAccessor) Priority() int        { return m.PriorityV }
-func (m *MockPriorityBandAccessor) PriorityName() string { return m.PriorityNameV }
-func (m *MockPriorityBandAccessor) PolicyState() any     { return m.PolicyStateV }
+func (m *MockPriorityBandAccessor) Priority() int    { return m.PriorityV }
+func (m *MockPriorityBandAccessor) PolicyState() any { return m.PolicyStateV }
 
 func (m *MockPriorityBandAccessor) FlowKeys() []types.FlowKey {
 	if m.FlowKeysFunc != nil {

pkg/epp/flowcontrol/registry/config.go

@@ -21,8 +21,6 @@ import (
 	"fmt"
 	"time"
 
-	"k8s.io/apimachinery/pkg/util/sets"
-
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontrol/contracts"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontrol/framework"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontrol/framework/plugins/interflow"
@@ -158,11 +156,6 @@ type PriorityBandConfig struct {
 	// Required.
 	Priority int
 
-	// PriorityName is a human-readable name for this priority band (e.g., "Critical", "Standard").
-	// It must be unique across all priority bands in the configuration.
-	// Required.
-	PriorityName string
-
 	// IntraFlowDispatchPolicy specifies the default name of the policy used to select a request from within a single
 	// flow's queue in this band.
 	// Optional: Defaults to defaultIntraFlowDispatchPolicy ("FCFS").
@@ -348,11 +341,11 @@ func NewConfig(handle fwkplugin.Handle, opts ...ConfigOption) (*Config, error) {
 	builder := &configBuilder{
 		config: &Config{
 			MaxBytes:               0, // no limit enforced
+			PriorityBands:          make(map[int]*PriorityBandConfig),
 			InitialShardCount:      defaultInitialShardCount,
 			FlowGCTimeout:          defaultFlowGCTimeout,
 			PriorityBandGCTimeout:  defaultPriorityBandGCTimeout,
 			EventChannelBufferSize: defaultEventChannelBufferSize,
-			PriorityBands:          make(map[int]*PriorityBandConfig),
 		},
 		checker: &runtimeCapabilityChecker{},
 	}
@@ -366,7 +359,7 @@ func NewConfig(handle fwkplugin.Handle, opts ...ConfigOption) (*Config, error) {
 	// Initialize DefaultPriorityBand if missing.
 	// This ensures we always have a template for dynamic provisioning.
 	if builder.config.DefaultPriorityBand == nil {
-		template, err := NewPriorityBandConfig(handle, 0, "Dynamic-Default")
+		template, err := NewPriorityBandConfig(handle, 0)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create default priority band: %w", err)
 		}
@@ -395,12 +388,10 @@ func NewConfig(handle fwkplugin.Handle, opts ...ConfigOption) (*Config, error) {
 func NewPriorityBandConfig(
 	handle fwkplugin.Handle,
 	priority int,
-	name string,
 	opts ...PriorityBandConfigOption,
 ) (*PriorityBandConfig, error) {
 	pb := &PriorityBandConfig{
-		Priority:     priority,
-		PriorityName: name,
+		Priority: priority,
 	}
 
 	if err := pb.applyDefaults(handle); err != nil {
@@ -440,9 +431,6 @@ func (p *PriorityBandConfig) applyDefaults(handle fwkplugin.Handle) error {
 
 // validate checks the integrity of a single band's configuration.
 func (p *PriorityBandConfig) validate(checker capabilityChecker) error {
-	if p.PriorityName == "" {
-		return fmt.Errorf("PriorityName is required for priority band %d", p.Priority)
-	}
 	if p.IntraFlowDispatchPolicy == "" {
 		return fmt.Errorf("IntraFlowDispatchPolicy required for priority band %d", p.Priority)
 	}
@@ -454,8 +442,7 @@ func (p *PriorityBandConfig) validate(checker capabilityChecker) error {
 	}
 	if checker != nil {
 		if err := checker.CheckCompatibility(p.IntraFlowDispatchPolicy, p.Queue); err != nil {
-			return fmt.Errorf("priority band %d (%s) configuration error: %w",
-				p.Priority, p.PriorityName, err)
+			return fmt.Errorf("priority band %d configuration error: %w", p.Priority, err)
 		}
 	}
 	return nil
@@ -488,13 +475,7 @@ func (c *Config) validate(checker capabilityChecker) error {
 	}
 
 	// Validate statically configured bands.
-	names := sets.New[string]()
 	for _, band := range c.PriorityBands {
-		if names.Has(band.PriorityName) {
-			return fmt.Errorf("duplicate priority name %q found", band.PriorityName)
-		}
-		names.Insert(band.PriorityName)
-
 		if err := band.validate(checker); err != nil {
 			return err
 		}
@@ -522,7 +503,6 @@ func (c *Config) partition(shardIndex, totalShards int) *ShardConfig {
 	for _, template := range c.PriorityBands {
 		shardBand := &PriorityBandConfig{
 			Priority:                template.Priority,
-			PriorityName:            template.PriorityName,
 			IntraFlowDispatchPolicy: template.IntraFlowDispatchPolicy,
 			FairnessPolicy:          template.FairnessPolicy,
 			Queue:                   template.Queue,