// Copyright 2022 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Local copy of Envoy xDS proto file, used for testing only.

syntax = "proto3";

package xds.service.orca.v3;

import "src/proto/grpc/testing/xds/v3/orca_load_report.proto";

import "google/protobuf/duration.proto";

// See section `Out-of-band (OOB) reporting` of the design document in
// :ref:`https://github.com/envoyproxy/envoy/issues/6614`.

// Out-of-band (OOB) load reporting service for the additional load reporting
// agent that does not sit in the request path. Reports are periodically sampled
// with sufficient frequency to provide temporal association with requests.
// OOB reporting compensates the limitation of in-band reporting in revealing
// costs for backends that do not provide a steady stream of telemetry such as
// long running stream operations and zero QPS services. This is a server
// streaming service, client needs to terminate current RPC and initiate
// a new call to change backend reporting frequency.
service OpenRcaService {
  rpc StreamCoreMetrics(OrcaLoadReportRequest) returns (stream xds.data.orca.v3.OrcaLoadReport);
}

message OrcaLoadReportRequest {
  // Interval for generating Open RCA core metric responses.
  google.protobuf.Duration report_interval = 1;
  // Request costs to collect. If this is empty, all known requests costs tracked by
  // the load reporting agent will be returned. This provides an opportunity for
  // the client to selectively obtain a subset of tracked costs.
  repeated string request_cost_names = 2;
}