syntax = "proto3";

package envoy.config.overload.v3;

import "google/protobuf/any.proto";
import "google/protobuf/duration.proto";
import "google/protobuf/struct.proto";

import "udpa/annotations/status.proto";
import "udpa/annotations/versioning.proto";
import "validate/validate.proto";

option java_package = "io.envoyproxy.envoy.config.overload.v3";
option java_outer_classname = "OverloadProto";
option java_multiple_files = true;
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: Overload Manager]

// The Overload Manager provides an extensible framework to protect Envoy instances
// from overload of various resources (memory, cpu, file descriptors, etc).
// It monitors a configurable set of resources and notifies registered listeners
// when triggers related to those resources fire.

message ResourceMonitor {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.overload.v2alpha.ResourceMonitor";

  reserved 2;

  reserved "config";

  // The name of the resource monitor to instantiate. Must match a registered
  // resource monitor type. The built-in resource monitors are:
  //
  // * :ref:`envoy.resource_monitors.fixed_heap
  //   <envoy_api_msg_config.resource_monitor.fixed_heap.v2alpha.FixedHeapConfig>`
  // * :ref:`envoy.resource_monitors.injected_resource
  //   <envoy_api_msg_config.resource_monitor.injected_resource.v2alpha.InjectedResourceConfig>`
  string name = 1 [(validate.rules).string = {min_bytes: 1}];

  // Configuration for the resource monitor being instantiated.
  oneof config_type {
    google.protobuf.Any typed_config = 3;
  }
}

message ThresholdTrigger {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.overload.v2alpha.ThresholdTrigger";

  // If the resource pressure is greater than or equal to this value, the trigger
  // will enter saturation.
  double value = 1 [(validate.rules).double = {lte: 1.0 gte: 0.0}];
}

message ScaledTrigger {
  // If the resource pressure is greater than this value, the trigger will be in the
  // :ref:`scaling <arch_overview_overload_manager-triggers-state>` state with value
  // `(pressure - scaling_threshold) / (saturation_threshold - scaling_threshold)`.
  double scaling_threshold = 1 [(validate.rules).double = {lte: 1.0 gte: 0.0}];

  // If the resource pressure is greater than this value, the trigger will enter saturation.
  double saturation_threshold = 2 [(validate.rules).double = {lte: 1.0 gte: 0.0}];
}

message Trigger {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.overload.v2alpha.Trigger";

  // The name of the resource this is a trigger for.
  string name = 1 [(validate.rules).string = {min_bytes: 1}];

  oneof trigger_oneof {
    option (validate.required) = true;

    ThresholdTrigger threshold = 2;

    ScaledTrigger scaled = 3;
  }
}

message OverloadAction {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.overload.v2alpha.OverloadAction";

  // The name of the overload action. This is just a well-known string that listeners can
  // use for registering callbacks. Custom overload actions should be named using reverse
  // DNS to ensure uniqueness.
  string name = 1 [(validate.rules).string = {min_bytes: 1}];

  // A set of triggers for this action. The state of the action is the maximum
  // state of all triggers, which can be scaling between 0 and 1 or saturated. Listeners
  // are notified when the overload action changes state.
  repeated Trigger triggers = 2 [(validate.rules).repeated = {min_items: 1}];
}

message OverloadManager {
  option (udpa.annotations.versioning).previous_message_type =
      "envoy.config.overload.v2alpha.OverloadManager";

  // The interval for refreshing resource usage.
  google.protobuf.Duration refresh_interval = 1;

  // The set of resources to monitor.
  repeated ResourceMonitor resource_monitors = 2 [(validate.rules).repeated = {min_items: 1}];

  // The set of overload actions.
  repeated OverloadAction actions = 3;
}