LB policy: add client-side weighted round robin LB policy config (#24520)

Signed-off-by: Mark D. Roth <roth@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 136c258dc29d1aa12be1d1c11a00800b38c7bbad

envoy/extensions/load_balancing_policies/client_side_weighted_round_robin/v3/BUILD

@@ -0,0 +1,9 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    deps = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+)

envoy/extensions/load_balancing_policies/client_side_weighted_round_robin/v3/client_side_weighted_round_robin.proto

@@ -0,0 +1,59 @@
+syntax = "proto3";
+
+package envoy.extensions.load_balancing_policies.client_side_weighted_round_robin.v3;
+
+import "google/protobuf/duration.proto";
+import "google/protobuf/wrappers.proto";
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.load_balancing_policies.client_side_weighted_round_robin.v3";
+option java_outer_classname = "ClientSideWeightedRoundRobinProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/load_balancing_policies/client_side_weighted_round_robin/v3;client_side_weighted_round_robinv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Client-Side Weighted Round Robin Load Balancing Policy]
+// [#not-implemented-hide:]
+
+// Configuration for the client_side_weighted_round_robin LB policy.
+//
+// This policy differs from the built-in ROUND_ROBIN policy in terms of
+// how the endpoint weights are determined. In the ROUND_ROBIN policy,
+// the endpoint weights are sent by the control plane via EDS. However,
+// in this policy, the endpoint weights are instead determined via
+// qps and CPU utilization metrics sent by the endpoint using the Open
+// Request Cost Aggregation (ORCA) protocol. The weight of a given endpoint
+// is computed as qps / cpu_utilization.
+//
+// See the :ref:`load balancing architecture overview<arch_overview_load_balancing_types>` for more information.
+//
+// [#next-free-field: 6]
+message ClientSideWeightedRoundRobin {
+  // Whether to enable out-of-band utilization reporting collection from
+  // the endpoints. By default, per-request utilization reporting is used.
+  google.protobuf.BoolValue enable_oob_load_report = 1;
+
+  // Load reporting interval to request from the server. Note that the
+  // server may not provide reports as frequently as the client requests.
+  // Used only when enable_oob_load_report is true. Default is 10 seconds.
+  google.protobuf.Duration oob_reporting_period = 2;
+
+  // A given endpoint must report load metrics continuously for at least
+  // this long before the endpoint weight will be used. This avoids
+  // churn when the set of endpoint addresses changes. Takes effect
+  // both immediately after we establish a connection to an endpoint and
+  // after weight_expiration_period has caused us to stop using the most
+  // recent load metrics. Default is 10 seconds.
+  google.protobuf.Duration blackout_period = 3;
+
+  // If a given endpoint has not reported load metrics in this long,
+  // then we stop using the reported weight. This ensures that we do
+  // not continue to use very stale weights. Once we stop using a stale
+  // value, if we later start seeing fresh reports again, the
+  // blackout_period applies. Defaults to 3 minutes.
+  google.protobuf.Duration weight_expiration_period = 4;
+
+  // How often endpoint weights are recalculated.  Default is 1 second.
+  google.protobuf.Duration weight_update_period = 5;
+}

versioning/BUILD

@@ -184,6 +184,7 @@ proto_library(
         "//envoy/extensions/internal_redirect/previous_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/safe_cross_scheme/v3:pkg",
         "//envoy/extensions/key_value/file_based/v3:pkg",
+        "//envoy/extensions/load_balancing_policies/client_side_weighted_round_robin/v3:pkg",
         "//envoy/extensions/load_balancing_policies/common/v3:pkg",
         "//envoy/extensions/load_balancing_policies/least_request/v3:pkg",
         "//envoy/extensions/load_balancing_policies/maglev/v3:pkg",