feat: add admission control and adaptive concurrency

api/v1alpha1/adaptive_concurrency_types.go

@@ -0,0 +1,132 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// AdaptiveConcurrency defines the adaptive concurrency configuration for backend traffic.
+// This feature dynamically adjusts the number of concurrent requests to optimize
+// performance and prevent overload based on downstream response times.
+//
+// +optional
+type AdaptiveConcurrency struct {
+	// Enabled enables or disables adaptive concurrency. Defaults to false.
+	//
+	// +optional
+	// +kubebuilder:default=false
+	Enabled *bool `json:"enabled,omitempty"`
+
+	// GradientController defines the gradient controller configuration for adaptive concurrency.
+	//
+	// +optional
+	GradientController *AdaptiveConcurrencyGradientController `json:"gradientController,omitempty"`
+
+	// MinRTTCalculation defines the minimum RTT calculation parameters.
+	//
+	// +optional
+	MinRTTCalculation *AdaptiveConcurrencyMinRTTCalculation `json:"minRTTCalculation,omitempty"`
+
+	// ConcurrencyLimitParams defines the concurrency limit parameters.
+	//
+	// +optional
+	ConcurrencyLimitParams *AdaptiveConcurrencyLimitParams `json:"concurrencyLimitParams,omitempty"`
+}
+
+// AdaptiveConcurrencyGradientController defines the gradient controller configuration.
+//
+// +optional
+type AdaptiveConcurrencyGradientController struct {
+	// SampleAggregatePercentile defines the percentile of request latencies to sample.
+	// This should be a value between 0 and 100.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=0
+	// +kubebuilder:validation:Maximum=100
+	// +kubebuilder:default=90
+	SampleAggregatePercentile *float64 `json:"sampleAggregatePercentile,omitempty"`
+
+	// ConcurrencyLimitParams defines the concurrency limit parameters.
+	//
+	// +optional
+	ConcurrencyLimitParams *AdaptiveConcurrencyLimitParams `json:"concurrencyLimitParams,omitempty"`
+
+	// MinRTTCalculation defines the minimum RTT calculation parameters.
+	//
+	// +optional
+	MinRTTCalculation *AdaptiveConcurrencyMinRTTCalculation `json:"minRTTCalculation,omitempty"`
+}
+
+// AdaptiveConcurrencyLimitParams defines the concurrency limit parameters.
+//
+// +optional
+type AdaptiveConcurrencyLimitParams struct {
+	// ConcurrencyUpdateInterval defines the interval at which the concurrency limit is updated.
+	//
+	// +optional
+	// +kubebuilder:default="0.1s"
+	ConcurrencyUpdateInterval *metav1.Duration `json:"concurrencyUpdateInterval,omitempty"`
+
+	// MaxConcurrencyLimit defines the maximum concurrency limit.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=1
+	// +kubebuilder:default=1000
+	MaxConcurrencyLimit *uint32 `json:"maxConcurrencyLimit,omitempty"`
+
+	// MinConcurrencyLimit defines the minimum concurrency limit.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=1
+	// +kubebuilder:default=1
+	MinConcurrencyLimit *uint32 `json:"minConcurrencyLimit,omitempty"`
+
+	// ConcurrencyUpdateRatio defines the ratio by which the concurrency limit is updated.
+	// This should be a value between 0.0 and 1.0.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=0.0
+	// +kubebuilder:validation:Maximum=1.0
+	// +kubebuilder:default=0.1
+	ConcurrencyUpdateRatio *float64 `json:"concurrencyUpdateRatio,omitempty"`
+}
+
+// AdaptiveConcurrencyMinRTTCalculation defines the minimum RTT calculation parameters.
+//
+// +optional
+type AdaptiveConcurrencyMinRTTCalculation struct {
+	// Interval defines the interval at which the minimum RTT is recalculated.
+	//
+	// +optional
+	// +kubebuilder:default="60s"
+	Interval *metav1.Duration `json:"interval,omitempty"`
+
+	// RequestCount defines the number of requests to use for minimum RTT calculation.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=1
+	// +kubebuilder:default=50
+	RequestCount *uint32 `json:"requestCount,omitempty"`
+
+	// Jitter defines the jitter to apply to the minimum RTT calculation interval.
+	// This should be a value between 0 and 100 representing a percentage.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=0
+	// +kubebuilder:validation:Maximum=100
+	// +kubebuilder:default=10
+	Jitter *float64 `json:"jitter,omitempty"`
+
+	// Buffer defines the buffer to apply to the minimum RTT calculation.
+	// This should be a value between 0 and 100 representing a percentage.
+	//
+	// +optional
+	// +kubebuilder:validation:Minimum=0
+	// +kubebuilder:validation:Maximum=100
+	// +kubebuilder:default=25
+	Buffer *float64 `json:"buffer,omitempty"`
+}

api/v1alpha1/admission_control_types.go

@@ -0,0 +1,116 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// AdmissionControl defines the admission control configuration for backend traffic.
+// This feature rejects a portion of requests when the success rate falls below
+// a specified threshold to prevent cascading failures.
+//
+// +optional
+type AdmissionControl struct {
+	// Enabled enables or disables admission control. Defaults to false.
+	//
+	// +optional
+	// +kubebuilder:default=false
+	Enabled *bool `json:"enabled,omitempty"`
+
+	// SuccessCriteria defines the criteria for determining request success.
+	//
+	// +optional
+	SuccessCriteria *AdmissionControlSuccessCriteria `json:"successCriteria,omitempty"`
+
+	// SamplingWindow defines the time window for sampling requests.
+	// Defaults to "30s".
+	//
+	// +optional
+	// +kubebuilder:default="30s"
+	SamplingWindow *metav1.Duration `json:"samplingWindow,omitempty"`
+
+	// Aggression defines how aggressively to reject requests when success rate is low.
+	// Must be between 1.0 and 10.0. Defaults to 1.0.
+	//
+	// +optional
+	// +kubebuilder:default=1.0
+	// +kubebuilder:validation:Minimum=1.0
+	// +kubebuilder:validation:Maximum=10.0
+	Aggression *float64 `json:"aggression,omitempty"`
+
+	// SRThreshold defines the success rate threshold below which admission control activates.
+	// Must be between 0.0 and 1.0. Defaults to 0.95.
+	//
+	// +optional
+	// +kubebuilder:default=0.95
+	// +kubebuilder:validation:Minimum=0.0
+	// +kubebuilder:validation:Maximum=1.0
+	SRThreshold *float64 `json:"srThreshold,omitempty"`
+
+	// RPSThreshold defines the minimum requests per second required for admission control.
+	// Defaults to 5.0.
+	//
+	// +optional
+	// +kubebuilder:default=5.0
+	// +kubebuilder:validation:Minimum=0.0
+	RPSThreshold *float64 `json:"rpsThreshold,omitempty"`
+
+	// MaxRejectionProbability defines the maximum probability of rejecting a request.
+	// Must be between 0.0 and 1.0. Defaults to 0.8.
+	//
+	// +optional
+	// +kubebuilder:default=0.8
+	// +kubebuilder:validation:Minimum=0.0
+	// +kubebuilder:validation:Maximum=1.0
+	MaxRejectionProbability *float64 `json:"maxRejectionProbability,omitempty"`
+}
+
+// AdmissionControlSuccessCriteria defines the criteria for determining request success.
+type AdmissionControlSuccessCriteria struct {
+	// HTTP defines success criteria for HTTP requests.
+	//
+	// +optional
+	HTTP *AdmissionControlHTTPSuccessCriteria `json:"http,omitempty"`
+
+	// GRPC defines success criteria for gRPC requests.
+	//
+	// +optional
+	GRPC *AdmissionControlGRPCSuccessCriteria `json:"grpc,omitempty"`
+}
+
+// AdmissionControlHTTPSuccessCriteria defines success criteria for HTTP requests.
+type AdmissionControlHTTPSuccessCriteria struct {
+	// HTTPSuccessStatus defines the HTTP status codes considered successful.
+	// If not specified, defaults to 200-299 range.
+	//
+	// +optional
+	HTTPSuccessStatus []AdmissionControlStatusRange `json:"httpSuccessStatus,omitempty"`
+}
+
+// AdmissionControlGRPCSuccessCriteria defines success criteria for gRPC requests.
+type AdmissionControlGRPCSuccessCriteria struct {
+	// GRPCSuccessStatus defines the gRPC status codes considered successful.
+	// If not specified, defaults to OK (0).
+	//
+	// +optional
+	GRPCSuccessStatus []AdmissionControlStatusRange `json:"grpcSuccessStatus,omitempty"`
+}
+
+// AdmissionControlStatusRange defines a range of status codes.
+type AdmissionControlStatusRange struct {
+	// Start defines the start of the status code range (inclusive).
+	//
+	// +kubebuilder:validation:Minimum=0
+	// +kubebuilder:validation:Maximum=999
+	Start int32 `json:"start"`
+
+	// End defines the end of the status code range (inclusive).
+	//
+	// +kubebuilder:validation:Minimum=0
+	// +kubebuilder:validation:Maximum=999
+	End int32 `json:"end"`
+}

api/v1alpha1/backendtrafficpolicy_types.go

@@ -121,6 +121,20 @@ type BackendTrafficPolicySpec struct {
 	//
 	// +optional
 	Telemetry *BackendTelemetry `json:"telemetry,omitempty"`
+
+	// AdmissionControl configures admission control for backend traffic.
+	// This feature rejects a portion of requests when the success rate falls below
+	// a specified threshold to prevent cascading failures.
+	//
+	// +optional
+	AdmissionControl *AdmissionControl `json:"admissionControl,omitempty"`
+
+	// AdaptiveConcurrency configures adaptive concurrency for backend traffic.
+	// This feature dynamically adjusts the number of concurrent requests to optimize
+	// performance and prevent overload based on downstream response times.
+	//
+	// +optional
+	AdaptiveConcurrency *AdaptiveConcurrency `json:"adaptiveConcurrency,omitempty"`
 }
 
 type BackendTelemetry struct {