Revert "Revert "Revert "Revert "server: introduce ServerMetricRecorde… (#32301)

* Revert "Revert "Revert "Revert "server: introduce ServerMetricRecorder API and move per-call reporting from a C++ interceptor to a C-core filter (#32106)" (#32272)" (#32279)" (#32293)" This reverts commit 1f960697c5. * Do not create CallMetricRecorder if call is null.
2 years ago · b98f527260
parent c9b47f8584
commit b98f527260
43 changed files with 1195 additions and 634 deletions
--- a/37
+++ b/37
@ -762,6 +762,7 @@ grpc_cc_library(
        "grpc_base",
        # standard plugins
        "census",
        "//src/core:grpc_backend_metric_filter",
        "//src/core:grpc_deadline_filter",
        "//src/core:grpc_client_authority_filter",
        "//src/core:grpc_lb_policy_grpclb",
@ -1823,6 +1824,7 @@ grpc_cc_library(
        "grpc_security_base",
        "grpc_service_config_impl",
        "grpc_trace",
        "grpcpp_backend_metric_recorder",
        "grpcpp_call_metric_recorder",
        "grpcpp_status",
        "iomgr_timer",
@ -1838,6 +1840,7 @@ grpc_cc_library(
        "//src/core:error",
        "//src/core:gpr_atm",
        "//src/core:gpr_manual_constructor",
        "//src/core:grpc_backend_metric_provider",
        "//src/core:grpc_service_config",
        "//src/core:grpc_transport_inproc",
        "//src/core:json",
@ -1890,6 +1893,7 @@ grpc_cc_library(
        "grpc_service_config_impl",
        "grpc_trace",
        "grpc_unsecure",
        "grpcpp_backend_metric_recorder",
        "grpcpp_call_metric_recorder",
        "grpcpp_status",
        "iomgr_timer",
@ -1901,6 +1905,7 @@ grpc_cc_library(
        "//src/core:error",
        "//src/core:gpr_atm",
        "//src/core:gpr_manual_constructor",
        "//src/core:grpc_backend_metric_provider",
        "//src/core:grpc_insecure_credentials",
        "//src/core:grpc_service_config",
        "//src/core:grpc_transport_inproc",
@ -1978,45 +1983,42 @@ grpc_cc_library(
 grpc_cc_library(
    name = "grpcpp_call_metric_recorder",
    srcs = [
        "src/cpp/server/orca/call_metric_recorder.cc",
    ],
    external_deps = [
        "absl/strings",
        "absl/types:optional",
        "upb_lib",
    ],
    language = "c++",
    public_hdrs = [
        "include/grpcpp/ext/call_metric_recorder.h",
    ],
    visibility = ["@grpc:public"],
-    deps = [
+    deps = ["grpc++_public_hdrs"],
        "grpc++_public_hdrs",
        "xds_orca_upb",
        "//src/core:arena",
        "//src/core:grpc_backend_metric_data",
    ],
 )
 grpc_cc_library(
-    name = "grpcpp_orca_interceptor",
+    name = "grpcpp_backend_metric_recorder",
    srcs = [
-        "src/cpp/server/orca/orca_interceptor.cc",
+        "src/cpp/server/backend_metric_recorder.cc",
    ],
    hdrs = [
-        "src/cpp/server/orca/orca_interceptor.h",
+        "src/cpp/server/backend_metric_recorder.h",
    ],
    external_deps = [
        "absl/base:core_headers",
        "absl/strings",
        "absl/types:optional",
    ],
    language = "c++",
    public_hdrs = [
        "include/grpcpp/ext/server_metric_recorder.h",
    ],
    visibility = ["@grpc:public"],
    deps = [
-        "grpc++",
+        "gpr",
-        "grpc_base",
+        "grpc++_public_hdrs",
        "grpc_trace",
        "grpcpp_call_metric_recorder",
        "//src/core:grpc_backend_metric_data",
        "//src/core:grpc_backend_metric_provider",
    ],
 )
@ -2027,6 +2029,7 @@ grpc_cc_library(
    ],
    external_deps = [
        "absl/base:core_headers",
        "absl/strings",
        "absl/time",
        "absl/types:optional",
        "upb_lib",
@ -2042,11 +2045,13 @@ grpc_cc_library(
        "gpr",
        "grpc++",
        "grpc_base",
        "grpcpp_backend_metric_recorder",
        "protobuf_duration_upb",
        "ref_counted_ptr",
        "xds_orca_service_upb",
        "xds_orca_upb",
        "//src/core:default_event_engine",
        "//src/core:grpc_backend_metric_data",
        "//src/core:ref_counted",
        "//src/core:time",
    ],
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -1704,6 +1704,7 @@ endif()
 add_library(grpc
  src/core/ext/filters/backend_metrics/backend_metric_filter.cc
  src/core/ext/filters/census/grpc_context.cc
  src/core/ext/filters/channel_idle/channel_idle_filter.cc
  src/core/ext/filters/channel_idle/idle_filter_state.cc
@ -2721,6 +2722,7 @@ endif()
 endif()
 add_library(grpc_unsecure
  src/core/ext/filters/backend_metrics/backend_metric_filter.cc
  src/core/ext/filters/census/grpc_context.cc
  src/core/ext/filters/channel_idle/channel_idle_filter.cc
  src/core/ext/filters/channel_idle/idle_filter_state.cc
@ -3357,6 +3359,7 @@ add_library(grpc++
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -3364,7 +3367,6 @@ add_library(grpc++
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -3503,6 +3505,7 @@ foreach(_hdr
  include/grpcpp/create_channel_posix.h
  include/grpcpp/ext/call_metric_recorder.h
  include/grpcpp/ext/health_check_service_server_builder_option.h
  include/grpcpp/ext/server_metric_recorder.h
  include/grpcpp/generic/async_generic_service.h
  include/grpcpp/generic/generic_stub.h
  include/grpcpp/grpcpp.h
@ -4062,6 +4065,7 @@ add_library(grpc++_unsecure
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -4069,7 +4073,6 @@ add_library(grpc++_unsecure
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
  src/cpp/server/server_cc.cc
@ -4205,6 +4208,7 @@ foreach(_hdr
  include/grpcpp/create_channel_posix.h
  include/grpcpp/ext/call_metric_recorder.h
  include/grpcpp/ext/health_check_service_server_builder_option.h
  include/grpcpp/ext/server_metric_recorder.h
  include/grpcpp/generic/async_generic_service.h
  include/grpcpp/generic/generic_stub.h
  include/grpcpp/grpcpp.h
@ -7140,6 +7144,7 @@ add_executable(binder_transport_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -7147,7 +7152,6 @@ add_executable(binder_transport_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -8810,7 +8814,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/orca_load_report.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/orca_load_report.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/orca_load_report.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    src/cpp/server/orca/orca_service.cc
    test/core/util/test_lb_policies.cc
    test/cpp/end2end/client_lb_end2end_test.cc
@ -10035,6 +10038,7 @@ add_executable(endpoint_binder_pool_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -10042,7 +10046,6 @@ add_executable(endpoint_binder_pool_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -10729,6 +10732,7 @@ add_executable(fake_binder_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -10736,7 +10740,6 @@ add_executable(fake_binder_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -21526,6 +21529,7 @@ add_executable(transport_stream_receiver_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -21533,7 +21537,6 @@ add_executable(transport_stream_receiver_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -22204,6 +22207,7 @@ add_executable(wire_reader_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -22211,7 +22215,6 @@ add_executable(wire_reader_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -22304,6 +22307,7 @@ add_executable(wire_writer_test
  src/cpp/common/validate_service_config.cc
  src/cpp/common/version_cc.cc
  src/cpp/server/async_generic_service.cc
  src/cpp/server/backend_metric_recorder.cc
  src/cpp/server/channel_argument_option.cc
  src/cpp/server/create_default_thread_pool.cc
  src/cpp/server/external_connection_acceptor_impl.cc
@ -22311,7 +22315,6 @@ add_executable(wire_writer_test
  src/cpp/server/health/health_check_service.cc
  src/cpp/server/health/health_check_service_server_builder_option.cc
  src/cpp/server/insecure_server_credentials.cc
  src/cpp/server/orca/call_metric_recorder.cc
  src/cpp/server/secure_server_credentials.cc
  src/cpp/server/server_builder.cc
  src/cpp/server/server_callback.cc
@ -22756,7 +22759,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/connection_attempt_injector.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_cluster_end2end_test.cc
@ -23031,7 +23033,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/connection_attempt_injector.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_cluster_type_end2end_test.cc
@ -23280,7 +23281,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_core_end2end_test.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -23560,7 +23560,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/csds/csds.cc
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_csds_end2end_test.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -23744,7 +23743,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/tls.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/tls.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/tls.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -23979,7 +23977,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
    test/cpp/end2end/xds/xds_fault_injection_end2end_test.cc
@ -24674,7 +24671,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
    test/cpp/end2end/xds/xds_outlier_detection_end2end_test.cc
@ -24854,7 +24850,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
    test/cpp/end2end/xds/xds_override_host_end2end_test.cc
@ -25100,7 +25095,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/connection_attempt_injector.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -25277,7 +25271,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/rls_server.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -25570,7 +25563,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/string.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
    test/cpp/end2end/xds/xds_routing_end2end_test.cc
@ -25746,7 +25738,6 @@ if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/wrr_locality.grpc.pb.cc
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/wrr_locality.pb.h
    ${_gRPC_PROTO_GENS_DIR}/src/proto/grpc/testing/xds/v3/wrr_locality.grpc.pb.h
    src/cpp/server/orca/orca_interceptor.cc
    test/cpp/end2end/test_service_impl.cc
    test/cpp/end2end/xds/xds_end2end_test_lib.cc
    test/cpp/end2end/xds/xds_server.cc
--- a/2
+++ b/2
@ -959,6 +959,7 @@ endif
 # start of build recipe for library "grpc" (generated by makelib(lib) template function)
 LIBGRPC_SRC = \
    src/core/ext/filters/backend_metrics/backend_metric_filter.cc \
    src/core/ext/filters/census/grpc_context.cc \
    src/core/ext/filters/channel_idle/channel_idle_filter.cc \
    src/core/ext/filters/channel_idle/idle_filter_state.cc \
@ -1829,6 +1830,7 @@ endif
 # start of build recipe for library "grpc_unsecure" (generated by makelib(lib) template function)
 LIBGRPC_UNSECURE_SRC = \
    src/core/ext/filters/backend_metrics/backend_metric_filter.cc \
    src/core/ext/filters/census/grpc_context.cc \
    src/core/ext/filters/channel_idle/channel_idle_filter.cc \
    src/core/ext/filters/channel_idle/idle_filter_state.cc \
--- a/build_autogenerated.yaml
+++ b/build_autogenerated.yaml
@ -326,6 +326,8 @@ libs:
  - include/grpc/support/time.h
  - include/grpc/support/workaround_list.h
  headers:
  - src/core/ext/filters/backend_metrics/backend_metric_filter.h
  - src/core/ext/filters/backend_metrics/backend_metric_provider.h
  - src/core/ext/filters/channel_idle/channel_idle_filter.h
  - src/core/ext/filters/channel_idle/idle_filter_state.h
  - src/core/ext/filters/client_channel/backend_metric.h
@ -1096,6 +1098,7 @@ libs:
  - src/core/tsi/transport_security_interface.h
  - third_party/xxhash/xxhash.h
  src:
  - src/core/ext/filters/backend_metrics/backend_metric_filter.cc
  - src/core/ext/filters/census/grpc_context.cc
  - src/core/ext/filters/channel_idle/channel_idle_filter.cc
  - src/core/ext/filters/channel_idle/idle_filter_state.cc
@ -1991,6 +1994,8 @@ libs:
  - include/grpc/support/time.h
  - include/grpc/support/workaround_list.h
  headers:
  - src/core/ext/filters/backend_metrics/backend_metric_filter.h
  - src/core/ext/filters/backend_metrics/backend_metric_provider.h
  - src/core/ext/filters/channel_idle/channel_idle_filter.h
  - src/core/ext/filters/channel_idle/idle_filter_state.h
  - src/core/ext/filters/client_channel/backend_metric.h
@ -2375,6 +2380,7 @@ libs:
  - src/core/tsi/transport_security_interface.h
  - third_party/xxhash/xxhash.h
  src:
  - src/core/ext/filters/backend_metrics/backend_metric_filter.cc
  - src/core/ext/filters/census/grpc_context.cc
  - src/core/ext/filters/channel_idle/channel_idle_filter.cc
  - src/core/ext/filters/channel_idle/idle_filter_state.cc
@ -2882,6 +2888,7 @@ libs:
  - include/grpcpp/create_channel_posix.h
  - include/grpcpp/ext/call_metric_recorder.h
  - include/grpcpp/ext/health_check_service_server_builder_option.h
  - include/grpcpp/ext/server_metric_recorder.h
  - include/grpcpp/generic/async_generic_service.h
  - include/grpcpp/generic/generic_stub.h
  - include/grpcpp/grpcpp.h
@ -3026,6 +3033,7 @@ libs:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -3077,6 +3085,7 @@ libs:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -3084,7 +3093,6 @@ libs:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -3301,6 +3309,7 @@ libs:
  - include/grpcpp/create_channel_posix.h
  - include/grpcpp/ext/call_metric_recorder.h
  - include/grpcpp/ext/health_check_service_server_builder_option.h
  - include/grpcpp/ext/server_metric_recorder.h
  - include/grpcpp/generic/async_generic_service.h
  - include/grpcpp/generic/generic_stub.h
  - include/grpcpp/grpcpp.h
@ -3420,6 +3429,7 @@ libs:
  headers:
  - src/cpp/client/create_channel_internal.h
  - src/cpp/common/channel_filter.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -3444,6 +3454,7 @@ libs:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -3451,7 +3462,6 @@ libs:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
  - src/cpp/server/server_cc.cc
@ -5091,6 +5101,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -5142,6 +5153,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -5149,7 +5161,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -5980,7 +5991,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/core/util/test_lb_policies.h
  - test/cpp/end2end/connection_attempt_injector.h
  - test/cpp/end2end/test_service_impl.h
@ -5990,7 +6000,6 @@ targets:
  - src/proto/grpc/testing/echo_messages.proto
  - src/proto/grpc/testing/simple_messages.proto
  - src/proto/grpc/testing/xds/v3/orca_load_report.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - src/cpp/server/orca/orca_service.cc
  - test/core/util/test_lb_policies.cc
  - test/cpp/end2end/client_lb_end2end_test.cc
@ -6450,6 +6459,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -6501,6 +6511,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -6508,7 +6519,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -6872,6 +6882,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -6923,6 +6934,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -6930,7 +6942,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -12137,6 +12148,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -12187,6 +12199,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -12194,7 +12207,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -12441,6 +12453,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -12492,6 +12505,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -12499,7 +12513,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -12545,6 +12558,7 @@ targets:
  - src/cpp/client/secure_credentials.h
  - src/cpp/common/channel_filter.h
  - src/cpp/common/secure_auth_context.h
  - src/cpp/server/backend_metric_recorder.h
  - src/cpp/server/dynamic_thread_pool.h
  - src/cpp/server/external_connection_acceptor_impl.h
  - src/cpp/server/health/default_health_check_service.h
@ -12596,6 +12610,7 @@ targets:
  - src/cpp/common/validate_service_config.cc
  - src/cpp/common/version_cc.cc
  - src/cpp/server/async_generic_service.cc
  - src/cpp/server/backend_metric_recorder.cc
  - src/cpp/server/channel_argument_option.cc
  - src/cpp/server/create_default_thread_pool.cc
  - src/cpp/server/external_connection_acceptor_impl.cc
@ -12603,7 +12618,6 @@ targets:
  - src/cpp/server/health/health_check_service.cc
  - src/cpp/server/health/health_check_service_server_builder_option.cc
  - src/cpp/server/insecure_server_credentials.cc
  - src/cpp/server/orca/call_metric_recorder.cc
  - src/cpp/server/secure_server_credentials.cc
  - src/cpp/server/server_builder.cc
  - src/cpp/server/server_callback.cc
@ -12728,7 +12742,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/connection_attempt_injector.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -12767,7 +12780,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/connection_attempt_injector.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_cluster_end2end_test.cc
@ -12814,7 +12826,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/connection_attempt_injector.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -12854,7 +12865,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/connection_attempt_injector.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_cluster_type_end2end_test.cc
@ -12905,7 +12915,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/core/util/scoped_env_var.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -12944,7 +12953,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_core_end2end_test.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -13011,7 +13019,6 @@ targets:
  language: c++
  headers:
  - src/cpp/server/csds/csds.h
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
  - test/cpp/end2end/xds/xds_end2end_test_lib.h
@ -13052,7 +13059,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/csds/csds.cc
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_csds_end2end_test.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -13070,7 +13076,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
  - test/cpp/end2end/xds/xds_end2end_test_lib.h
@ -13112,7 +13117,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/proto/grpc/testing/xds/v3/tls.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -13148,7 +13152,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
  - test/cpp/end2end/xds/xds_end2end_test_lib.h
@ -13188,7 +13191,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
  - test/cpp/end2end/xds/xds_fault_injection_end2end_test.cc
@ -13385,7 +13387,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
  - test/cpp/end2end/xds/xds_end2end_test_lib.h
@ -13425,7 +13426,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
  - test/cpp/end2end/xds/xds_outlier_detection_end2end_test.cc
@ -13442,7 +13442,6 @@ targets:
  build: test
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/core/util/scoped_env_var.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -13484,7 +13483,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/stateful_session.proto
  - src/proto/grpc/testing/xds/v3/stateful_session_cookie.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
  - test/cpp/end2end/xds/xds_override_host_end2end_test.cc
@ -13523,7 +13521,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/connection_attempt_injector.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -13563,7 +13560,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/connection_attempt_injector.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -13581,7 +13577,6 @@ targets:
  build: test
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/core/util/scoped_env_var.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/rls_server.h
@ -13623,7 +13618,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/rls_server.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -13684,7 +13678,6 @@ targets:
  run: false
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
  - test/cpp/end2end/xds/xds_end2end_test_lib.h
@ -13724,7 +13717,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/route.proto
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
  - test/cpp/end2end/xds/xds_routing_end2end_test.cc
@ -13741,7 +13733,6 @@ targets:
  build: test
  language: c++
  headers:
  - src/cpp/server/orca/orca_interceptor.h
  - test/core/util/scoped_env_var.h
  - test/cpp/end2end/counted_service.h
  - test/cpp/end2end/test_service_impl.h
@ -13782,7 +13773,6 @@ targets:
  - src/proto/grpc/testing/xds/v3/router.proto
  - src/proto/grpc/testing/xds/v3/string.proto
  - src/proto/grpc/testing/xds/v3/wrr_locality.proto
  - src/cpp/server/orca/orca_interceptor.cc
  - test/cpp/end2end/test_service_impl.cc
  - test/cpp/end2end/xds/xds_end2end_test_lib.cc
  - test/cpp/end2end/xds/xds_server.cc
--- a/config.m4
+++ b/config.m4
@ -40,6 +40,7 @@ if test "$PHP_GRPC" != "no"; then
  PHP_SUBST(GRPC_SHARED_LIBADD)
  PHP_NEW_EXTENSION(grpc,
    src/core/ext/filters/backend_metrics/backend_metric_filter.cc \
    src/core/ext/filters/census/grpc_context.cc \
    src/core/ext/filters/channel_idle/channel_idle_filter.cc \
    src/core/ext/filters/channel_idle/idle_filter_state.cc \
@ -1269,6 +1270,7 @@ if test "$PHP_GRPC" != "no"; then
    -DGRPC_XDS_USER_AGENT_NAME_SUFFIX='"\"PHP\""' \
    -DGRPC_XDS_USER_AGENT_VERSION_SUFFIX='"\"1.53.0dev\""')
  PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/backend_metrics)
  PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/census)
  PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/channel_idle)
  PHP_ADD_BUILD_DIR($ext_builddir/src/core/ext/filters/client_channel)
--- a/config.w32
+++ b/config.w32
@ -6,6 +6,7 @@ ARG_WITH("grpc", "grpc support", "no");
 if (PHP_GRPC != "no") {
  EXTENSION("grpc",
    "src\\core\\ext\\filters\\backend_metrics\\backend_metric_filter.cc " +
    "src\\core\\ext\\filters\\census\\grpc_context.cc " +
    "src\\core\\ext\\filters\\channel_idle\\channel_idle_filter.cc " +
    "src\\core\\ext\\filters\\channel_idle\\idle_filter_state.cc " +
@ -1267,6 +1268,7 @@ if (PHP_GRPC != "no") {
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\filters");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\filters\\backend_metrics");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\filters\\census");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\filters\\channel_idle");
  FSO.CreateFolder(base_dir+"\\ext\\grpc\\src\\core\\ext\\filters\\client_channel");
--- a/gRPC-C++.podspec
+++ b/gRPC-C++.podspec
@ -91,6 +91,7 @@ Pod::Spec.new do |s|
                      'include/grpcpp/create_channel_posix.h',
                      'include/grpcpp/ext/call_metric_recorder.h',
                      'include/grpcpp/ext/health_check_service_server_builder_option.h',
                      'include/grpcpp/ext/server_metric_recorder.h',
                      'include/grpcpp/generic/async_generic_service.h',
                      'include/grpcpp/generic/generic_stub.h',
                      'include/grpcpp/grpcpp.h',
@ -238,7 +239,9 @@ Pod::Spec.new do |s|
    ss.dependency 'abseil/types/variant', abseil_version
    ss.dependency 'abseil/utility/utility', abseil_version
-    ss.source_files = 'src/core/ext/filters/channel_idle/channel_idle_filter.h',
+    ss.source_files = 'src/core/ext/filters/backend_metrics/backend_metric_filter.h',
                      'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                      'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                      'src/core/ext/filters/channel_idle/idle_filter_state.h',
                      'src/core/ext/filters/client_channel/backend_metric.h',
                      'src/core/ext/filters/client_channel/backup_poller.h',
@ -1100,6 +1103,8 @@ Pod::Spec.new do |s|
                      'src/cpp/common/validate_service_config.cc',
                      'src/cpp/common/version_cc.cc',
                      'src/cpp/server/async_generic_service.cc',
                      'src/cpp/server/backend_metric_recorder.cc',
                      'src/cpp/server/backend_metric_recorder.h',
                      'src/cpp/server/channel_argument_option.cc',
                      'src/cpp/server/create_default_thread_pool.cc',
                      'src/cpp/server/dynamic_thread_pool.h',
@ -1110,7 +1115,6 @@ Pod::Spec.new do |s|
                      'src/cpp/server/health/health_check_service.cc',
                      'src/cpp/server/health/health_check_service_server_builder_option.cc',
                      'src/cpp/server/insecure_server_credentials.cc',
                      'src/cpp/server/orca/call_metric_recorder.cc',
                      'src/cpp/server/secure_server_credentials.cc',
                      'src/cpp/server/secure_server_credentials.h',
                      'src/cpp/server/server_builder.cc',
@ -1185,7 +1189,9 @@ Pod::Spec.new do |s|
                      'third_party/upb/upb/upb.hpp',
                      'third_party/xxhash/xxhash.h'
-    ss.private_header_files = 'src/core/ext/filters/channel_idle/channel_idle_filter.h',
+    ss.private_header_files = 'src/core/ext/filters/backend_metrics/backend_metric_filter.h',
                              'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                              'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                              'src/core/ext/filters/channel_idle/idle_filter_state.h',
                              'src/core/ext/filters/client_channel/backend_metric.h',
                              'src/core/ext/filters/client_channel/backup_poller.h',
@ -2003,6 +2009,7 @@ Pod::Spec.new do |s|
                              'src/cpp/client/secure_credentials.h',
                              'src/cpp/common/channel_filter.h',
                              'src/cpp/common/secure_auth_context.h',
                              'src/cpp/server/backend_metric_recorder.h',
                              'src/cpp/server/dynamic_thread_pool.h',
                              'src/cpp/server/external_connection_acceptor_impl.h',
                              'src/cpp/server/health/default_health_check_service.h',
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@ -206,7 +206,10 @@ Pod::Spec.new do |s|
    ss.dependency 'abseil/utility/utility', abseil_version
    ss.compiler_flags = '-DBORINGSSL_PREFIX=GRPC -Wno-unreachable-code -Wno-shorten-64-to-32'
-    ss.source_files = 'src/core/ext/filters/census/grpc_context.cc',
+    ss.source_files = 'src/core/ext/filters/backend_metrics/backend_metric_filter.cc',
                      'src/core/ext/filters/backend_metrics/backend_metric_filter.h',
                      'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                      'src/core/ext/filters/census/grpc_context.cc',
                      'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
                      'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                      'src/core/ext/filters/channel_idle/idle_filter_state.cc',
@ -1891,7 +1894,9 @@ Pod::Spec.new do |s|
                      'third_party/upb/upb/upb.h',
                      'third_party/upb/upb/upb.hpp',
                      'third_party/xxhash/xxhash.h'
-    ss.private_header_files = 'src/core/ext/filters/channel_idle/channel_idle_filter.h',
+    ss.private_header_files = 'src/core/ext/filters/backend_metrics/backend_metric_filter.h',
                              'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                              'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                              'src/core/ext/filters/channel_idle/idle_filter_state.h',
                              'src/core/ext/filters/client_channel/backend_metric.h',
                              'src/core/ext/filters/client_channel/backup_poller.h',
--- a/grpc.gemspec
+++ b/grpc.gemspec
@ -115,6 +115,9 @@ Gem::Specification.new do |s|
  s.files += %w( include/grpc/support/thd_id.h )
  s.files += %w( include/grpc/support/time.h )
  s.files += %w( include/grpc/support/workaround_list.h )
  s.files += %w( src/core/ext/filters/backend_metrics/backend_metric_filter.cc )
  s.files += %w( src/core/ext/filters/backend_metrics/backend_metric_filter.h )
  s.files += %w( src/core/ext/filters/backend_metrics/backend_metric_provider.h )
  s.files += %w( src/core/ext/filters/census/grpc_context.cc )
  s.files += %w( src/core/ext/filters/channel_idle/channel_idle_filter.cc )
  s.files += %w( src/core/ext/filters/channel_idle/channel_idle_filter.h )
--- a/grpc.gyp
+++ b/grpc.gyp
@ -372,6 +372,7 @@
        'upb',
      ],
      'sources': [
        'src/core/ext/filters/backend_metrics/backend_metric_filter.cc',
        'src/core/ext/filters/census/grpc_context.cc',
        'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
        'src/core/ext/filters/channel_idle/idle_filter_state.cc',
@ -1184,6 +1185,7 @@
        'upb',
      ],
      'sources': [
        'src/core/ext/filters/backend_metrics/backend_metric_filter.cc',
        'src/core/ext/filters/census/grpc_context.cc',
        'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
        'src/core/ext/filters/channel_idle/idle_filter_state.cc',
@ -1623,6 +1625,7 @@
        'src/cpp/common/validate_service_config.cc',
        'src/cpp/common/version_cc.cc',
        'src/cpp/server/async_generic_service.cc',
        'src/cpp/server/backend_metric_recorder.cc',
        'src/cpp/server/channel_argument_option.cc',
        'src/cpp/server/create_default_thread_pool.cc',
        'src/cpp/server/external_connection_acceptor_impl.cc',
@ -1630,7 +1633,6 @@
        'src/cpp/server/health/health_check_service.cc',
        'src/cpp/server/health/health_check_service_server_builder_option.cc',
        'src/cpp/server/insecure_server_credentials.cc',
        'src/cpp/server/orca/call_metric_recorder.cc',
        'src/cpp/server/secure_server_credentials.cc',
        'src/cpp/server/server_builder.cc',
        'src/cpp/server/server_callback.cc',
@ -1756,6 +1758,7 @@
        'src/cpp/common/validate_service_config.cc',
        'src/cpp/common/version_cc.cc',
        'src/cpp/server/async_generic_service.cc',
        'src/cpp/server/backend_metric_recorder.cc',
        'src/cpp/server/channel_argument_option.cc',
        'src/cpp/server/create_default_thread_pool.cc',
        'src/cpp/server/external_connection_acceptor_impl.cc',
@ -1763,7 +1766,6 @@
        'src/cpp/server/health/health_check_service.cc',
        'src/cpp/server/health/health_check_service_server_builder_option.cc',
        'src/cpp/server/insecure_server_credentials.cc',
        'src/cpp/server/orca/call_metric_recorder.cc',
        'src/cpp/server/server_builder.cc',
        'src/cpp/server/server_callback.cc',
        'src/cpp/server/server_cc.cc',
--- a/include/grpc/impl/grpc_types.h
+++ b/include/grpc/impl/grpc_types.h
@ -141,6 +141,9 @@ typedef struct {
 #define GRPC_ARG_ENABLE_CENSUS "grpc.census"
 /** If non-zero, enable load reporting. */
 #define GRPC_ARG_ENABLE_LOAD_REPORTING "grpc.loadreporting"
 /** If non-zero, call metric recording is enabled. */
 #define GRPC_ARG_SERVER_CALL_METRIC_RECORDING \
  "grpc.server_call_metric_recording"
 /** Request that optional features default to off (regardless of what they
    usually default to) - to enable tight control over what gets enabled */
 #define GRPC_ARG_MINIMAL_STACK "grpc.minimal_stack"
--- a/include/grpcpp/ext/call_metric_recorder.h
+++ b/include/grpcpp/ext/call_metric_recorder.h
@ -28,43 +28,30 @@
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/support/slice.h>
 namespace grpc_core {
 class Arena;
 struct BackendMetricData;
 }  // namespace grpc_core
 namespace grpc {
 class ServerBuilder;
 namespace experimental {
 class OrcaServerInterceptor;
 // Registers the per-rpc orca load reporter into the \a ServerBuilder.
 // Once this is done, the server will automatically send the load metrics
 // after each RPC as they were reported. In order to report load metrics,
 // call the \a ServerContext::ExperimentalGetCallMetricRecorder() method to
 // retrieve the recorder for the current call.
 void EnableCallMetricRecording(ServerBuilder*);
 /// Records call metrics for the purpose of load balancing.
 /// During an RPC, call \a ServerContext::ExperimentalGetCallMetricRecorder()
 /// method to retrive the recorder for the current call.
 class CallMetricRecorder {
 public:
-  explicit CallMetricRecorder(grpc_core::Arena* arena);
+  virtual ~CallMetricRecorder() = default;
  ~CallMetricRecorder();
  /// Records a call metric measurement for CPU utilization.
  /// Multiple calls to this method will override the stored value.
-  CallMetricRecorder& RecordCpuUtilizationMetric(double value);
+  /// Values outside of the valid range [0, 1] are ignored.
  virtual CallMetricRecorder& RecordCpuUtilizationMetric(double value) = 0;
  /// Records a call metric measurement for memory utilization.
  /// Multiple calls to this method will override the stored value.
-  CallMetricRecorder& RecordMemoryUtilizationMetric(double value);
+  /// Values outside of the valid range [0, 1] are ignored.
  virtual CallMetricRecorder& RecordMemoryUtilizationMetric(double value) = 0;
-  /// Records a call metric measurement for QPS.
+  /// Records a call metric measurement for queries per second.
  /// Multiple calls to this method will override the stored value.
-  CallMetricRecorder& RecordQpsMetric(double value);
+  /// Values outside of the valid range [0, infy) are ignored.
  virtual CallMetricRecorder& RecordQpsMetric(double value) = 0;
  /// Records a call metric measurement for utilization.
  /// Multiple calls to this method with the same name will
@ -73,7 +60,9 @@ class CallMetricRecorder {
  /// itself, since it's going to be sent as trailers after the RPC
  /// finishes. It is assumed the strings are common names that
  /// are global constants.
-  CallMetricRecorder& RecordUtilizationMetric(string_ref name, double value);
+  /// Values outside of the valid range [0, 1] are ignored.
  virtual CallMetricRecorder& RecordUtilizationMetric(string_ref name,
                                                      double value) = 0;
  /// Records a call metric measurement for request cost.
  /// Multiple calls to this method with the same name will
@ -82,14 +71,8 @@ class CallMetricRecorder {
  /// itself, since it's going to be sent as trailers after the RPC
  /// finishes. It is assumed the strings are common names that
  /// are global constants.
-  CallMetricRecorder& RecordRequestCostMetric(string_ref name, double value);
+  virtual CallMetricRecorder& RecordRequestCostMetric(string_ref name,
-
+                                                      double value) = 0;
 private:
  absl::optional<std::string> CreateSerializedReport();
  internal::Mutex mu_;
  grpc_core::BackendMetricData* backend_metric_data_ ABSL_GUARDED_BY(&mu_);
  friend class experimental::OrcaServerInterceptor;
 };
 }  // namespace experimental
--- a/include/grpcpp/ext/orca_service.h
+++ b/include/grpcpp/ext/orca_service.h
@ -23,6 +23,7 @@
 #include "absl/time/time.h"
 #include "absl/types/optional.h"
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/impl/service_type.h>
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/server_builder.h>
@ -48,38 +49,22 @@ class OrcaService : public Service {
    }
  };
-  explicit OrcaService(Options options);
+  // ServerMetricRecorder is required.
-
+  OrcaService(ServerMetricRecorder* const server_metric_recorder,
-  // Sets or removes the CPU utilization value to be reported to clients.
+              Options options);
  void SetCpuUtilization(double cpu_utilization);
  void DeleteCpuUtilization();
  // Sets of removes the memory utilization value to be reported to clients.
  void SetMemoryUtilization(double memory_utilization);
  void DeleteMemoryUtilization();
  // Sets of removes the QPS value to be reported to clients.
  void SetQps(double qps);
  void DeleteQps();
  // Sets or removed named utilization values to be reported to clients.
  void SetNamedUtilization(std::string name, double utilization);
  void DeleteNamedUtilization(const std::string& name);
  void SetAllNamedUtilization(std::map<std::string, double> named_utilization);
 private:
  class Reactor;
  Slice GetOrCreateSerializedResponse();
  const ServerMetricRecorder* const server_metric_recorder_;
  const absl::Duration min_report_duration_;
  grpc::internal::Mutex mu_;
-  double cpu_utilization_ ABSL_GUARDED_BY(&mu_) = -1;
+  // Contains the last serialized metrics from server_metric_recorder_.
-  double memory_utilization_ ABSL_GUARDED_BY(&mu_) = -1;
+  absl::optional<Slice> response_slice_ ABSL_GUARDED_BY(mu_);
-  double qps_ ABSL_GUARDED_BY(&mu_) = -1;
+  // The update sequence number of metrics serialized in response_slice_.
-  std::map<std::string, double> named_utilization_ ABSL_GUARDED_BY(&mu_);
+  absl::optional<uint64_t> response_slice_seq_ ABSL_GUARDED_BY(mu_);
  absl::optional<Slice> response_slice_ ABSL_GUARDED_BY(&mu_);
 };
 }  // namespace experimental
--- a/include/grpcpp/ext/server_metric_recorder.h
+++ b/include/grpcpp/ext/server_metric_recorder.h
@ -0,0 +1,108 @@
 //
 //
 // Copyright 2023 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.
 //
 //
 #ifndef GRPCPP_EXT_SERVER_METRIC_RECORDER_H
 #define GRPCPP_EXT_SERVER_METRIC_RECORDER_H
 #include <functional>
 #include <map>
 #include <memory>
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/support/string_ref.h>
 namespace grpc_core {
 struct BackendMetricData;
 }  // namespace grpc_core
 namespace grpc {
 class BackendMetricState;
 namespace experimental {
 /// Records server wide metrics to be reported to the client.
 /// Server implementation creates an instance and reports server metrics to it,
 /// and then passes it to
 /// ServerBuilder::experimental_type::EnableCallMetricRecording or
 /// experimental::OrcaService that read metrics to include in the report.
 class ServerMetricRecorder {
 public:
  // Factory method. Use this to create.
  static std::unique_ptr<ServerMetricRecorder> Create();
  /// Records the server CPU utilization in the range [0, 1].
  /// Values outside of the valid range are rejected.
  /// Overrides the stored value when called again with a valid value.
  void SetCpuUtilization(double value);
  /// Records the server memory utilization in the range [0, 1].
  /// Values outside of the valid range are rejected.
  /// Overrides the stored value when called again with a valid value.
  void SetMemoryUtilization(double value);
  /// Records number of queries per second to the server in the range [0, infy).
  /// Values outside of the valid range are rejected.
  /// Overrides the stored value when called again with a valid value.
  void SetQps(double value);
  /// Records a named resource utilization value in the range [0, 1].
  /// Values outside of the valid range are rejected.
  /// Overrides the stored value when called again with the same name.
  /// The name string should remain valid while this utilization remains
  /// in this recorder. It is assumed that strings are common names that are
  /// global constants.
  void SetNamedUtilization(string_ref name, double value);
  /// Replaces all named resource utilization values. No range validation.
  /// The name strings should remain valid while utilization values remain
  /// in this recorder. It is assumed that strings are common names that are
  /// global constants.
  void SetAllNamedUtilization(std::map<string_ref, double> named_utilization);
  /// Clears the server CPU utilization if recorded.
  void ClearCpuUtilization();
  /// Clears the server memory utilization if recorded.
  void ClearMemoryUtilization();
  /// Clears number of queries per second to the server if recorded.
  void ClearQps();
  /// Clears a named utilization value if exists.
  void ClearNamedUtilization(string_ref name);
 private:
  // To access GetMetrics().
  friend class grpc::BackendMetricState;
  friend class OrcaService;
  struct BackendMetricDataState;
  // No direct creation, use the factory method Create() above.
  ServerMetricRecorder();
  // Updates the metric state by applying `updater` to the data and incrementing
  // the sequence number.
  void UpdateBackendMetricDataState(
      std::function<void(grpc_core::BackendMetricData*)> updater);
  grpc_core::BackendMetricData GetMetrics() const;
  // Returned metric data is guaranteed to be identical between two calls if the
  // sequence numbers match.
  std::shared_ptr<const BackendMetricDataState> GetMetricsIfChanged() const;
  mutable grpc::internal::Mutex mu_;
  std::shared_ptr<const BackendMetricDataState> metric_state_
      ABSL_GUARDED_BY(mu_);
 };
 }  // namespace experimental
 }  // namespace grpc
 #endif  // GRPCPP_EXT_SERVER_METRIC_RECORDER_H
--- a/include/grpcpp/server.h
+++ b/include/grpcpp/server.h
@ -183,7 +183,8 @@ class Server : public ServerInterface, private internal::GrpcLibrary {
         std::vector<
             std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
             interceptor_creators = std::vector<std::unique_ptr<
-                 experimental::ServerInterceptorFactoryInterface>>());
+                 experimental::ServerInterceptorFactoryInterface>>(),
         experimental::ServerMetricRecorder* server_metric_recorder = nullptr);
  /// Start the server.
  ///
@ -255,6 +256,14 @@ class Server : public ServerInterface, private internal::GrpcLibrary {
    return max_receive_message_size_;
  }
  bool call_metric_recording_enabled() const override {
    return call_metric_recording_enabled_;
  }
  experimental::ServerMetricRecorder* server_metric_recorder() const override {
    return server_metric_recorder_;
  }
  CompletionQueue* CallbackCQ() ABSL_LOCKS_EXCLUDED(mu_) override;
  ServerInitializer* initializer();
@ -338,6 +347,12 @@ class Server : public ServerInterface, private internal::GrpcLibrary {
  // Shutdown.  Even though this is only used with NDEBUG, instantiate it in all
  // cases since otherwise the size will be inconsistent.
  std::vector<CompletionQueue*> cq_list_;
  // Whetner per-call load reporting is enabled.
  bool call_metric_recording_enabled_ = false;
  // Interface to read or update server-wide metrics. Optional.
  experimental::ServerMetricRecorder* server_metric_recorder_ = nullptr;
 };
 }  // namespace grpc
--- a/include/grpcpp/server_builder.h
+++ b/include/grpcpp/server_builder.h
@ -59,7 +59,6 @@ class ExternalConnectionAcceptorImpl;
 class CallbackGenericService;
 namespace experimental {
 class OrcaServerInterceptorFactory;
 // EXPERIMENTAL API:
 // Interface for a grpc server to build transports with connections created out
 // of band.
@ -283,6 +282,16 @@ class ServerBuilder {
        std::shared_ptr<experimental::AuthorizationPolicyProviderInterface>
            provider);
    /// Enables per-call load reporting. The server will automatically send the
    /// load metrics after each RPC. The caller can report load metrics for the
    /// current call to what ServerContext::ExperimentalGetCallMetricRecorder()
    /// returns. The server merges metrics from the optional
    /// server_metric_recorder when provided where the call metric recorder take
    /// a higher precedence. The caller owns and must ensure the server metric
    /// recorder outlives the server.
    void EnableCallMetricRecording(
        experimental::ServerMetricRecorder* server_metric_recorder = nullptr);
   private:
    ServerBuilder* builder_;
  };
@ -355,7 +364,6 @@ class ServerBuilder {
 private:
  friend class grpc::testing::ServerBuilderPluginTest;
  friend class grpc::experimental::OrcaServerInterceptorFactory;
  struct SyncServerSettings {
    SyncServerSettings()
@ -406,14 +414,12 @@ class ServerBuilder {
  std::vector<
      std::unique_ptr<grpc::experimental::ServerInterceptorFactoryInterface>>
      interceptor_creators_;
  std::vector<
      std::unique_ptr<grpc::experimental::ServerInterceptorFactoryInterface>>
      internal_interceptor_creators_;
  std::vector<std::shared_ptr<grpc::internal::ExternalConnectionAcceptorImpl>>
      acceptors_;
  grpc_server_config_fetcher* server_config_fetcher_ = nullptr;
  std::shared_ptr<experimental::AuthorizationPolicyProviderInterface>
      authorization_provider_;
  experimental::ServerMetricRecorder* server_metric_recorder_ = nullptr;
 };
 }  // namespace grpc
--- a/include/grpcpp/server_context.h
+++ b/include/grpcpp/server_context.h
@ -116,8 +116,8 @@ class DefaultReactorTestPeer;
 }  // namespace testing
 namespace experimental {
 class OrcaServerInterceptor;
 class CallMetricRecorder;
 class ServerMetricRecorder;
 }  // namespace experimental
 /// Base class of ServerContext.
@ -404,7 +404,6 @@ class ServerContextBase {
  friend class grpc::ClientContext;
  friend class grpc::GenericServerContext;
  friend class grpc::GenericCallbackServerContext;
  friend class grpc::experimental::OrcaServerInterceptor;
  /// Prevent copying.
  ServerContextBase(const ServerContextBase&);
@ -418,7 +417,13 @@ class ServerContextBase {
  /// Return the tag queued by BeginCompletionOp()
  grpc::internal::CompletionQueueTag* GetCompletionOpTag();
-  void set_call(grpc_call* call) { call_.call = call; }
+  void set_call(grpc_call* call, bool call_metric_recording_enabled,
                experimental::ServerMetricRecorder* server_metric_recorder) {
    call_.call = call;
    if (call_metric_recording_enabled) {
      CreateCallMetricRecorder(server_metric_recorder);
    }
  }
  void BindDeadlineAndMetadata(gpr_timespec deadline, grpc_metadata_array* arr);
@ -445,7 +450,10 @@ class ServerContextBase {
    }
  }
-  void CreateCallMetricRecorder();
+  // This should be called only once and only when call metric recording is
  // enabled.
  void CreateCallMetricRecorder(
      experimental::ServerMetricRecorder* server_metric_recorder = nullptr);
  struct CallWrapper {
    ~CallWrapper();
--- a/include/grpcpp/server_interface.h
+++ b/include/grpcpp/server_interface.h
@ -54,6 +54,7 @@ class CallbackGenericService;
 namespace experimental {
 class ServerInterceptorFactoryInterface;
 class ServerMetricRecorder;
 }  // namespace experimental
 class ServerInterface : public internal::CallHook {
@ -185,6 +186,8 @@ class ServerInterface : public internal::CallHook {
    internal::Call call_wrapper_;
    internal::InterceptorBatchMethodsImpl interceptor_methods_;
    bool done_intercepting_;
    bool call_metric_recording_enabled_;
    experimental::ServerMetricRecorder* server_metric_recorder_;
  };
  /// RegisteredAsyncRequest is not part of the C++ API
@ -350,6 +353,13 @@ class ServerInterface : public internal::CallHook {
    return nullptr;
  }
  // Whether per-call load reporting is enabled.
  virtual bool call_metric_recording_enabled() const = 0;
  // Interface to read or update server-wide metrics. Returns null when not set.
  virtual experimental::ServerMetricRecorder* server_metric_recorder()
      const = 0;
  // A method to get the callbackable completion queue associated with this
  // server. If the return value is nullptr, this server doesn't support
  // callback operations.
--- a/package.xml
+++ b/package.xml
@ -97,6 +97,9 @@
    <file baseinstalldir="/" name="include/grpc/support/thd_id.h" role="src" />
    <file baseinstalldir="/" name="include/grpc/support/time.h" role="src" />
    <file baseinstalldir="/" name="include/grpc/support/workaround_list.h" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/backend_metrics/backend_metric_filter.cc" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/backend_metrics/backend_metric_filter.h" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/backend_metrics/backend_metric_provider.h" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/census/grpc_context.cc" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/channel_idle_filter.cc" role="src" />
    <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/channel_idle_filter.h" role="src" />
--- a/src/core/BUILD
+++ b/src/core/BUILD
@ -3685,6 +3685,14 @@ grpc_cc_library(
    deps = ["//:gpr_platform"],
 )
 grpc_cc_library(
    name = "grpc_backend_metric_provider",
    hdrs = [
        "ext/filters/backend_metrics/backend_metric_provider.h",
    ],
    language = "c++",
 )
 grpc_cc_library(
    name = "grpc_lb_policy_rls",
    srcs = [
@ -4715,6 +4723,41 @@ grpc_cc_library(
    alwayslink = 1,
 )
 grpc_cc_library(
    name = "grpc_backend_metric_filter",
    srcs = [
        "ext/filters/backend_metrics/backend_metric_filter.cc",
    ],
    hdrs = [
        "ext/filters/backend_metrics/backend_metric_filter.h",
    ],
    external_deps = [
        "absl/status:statusor",
        "absl/strings",
        "absl/types:optional",
        "upb_lib",
    ],
    language = "c++",
    deps = [
        "arena_promise",
        "channel_args",
        "channel_fwd",
        "channel_stack_type",
        "context",
        "grpc_backend_metric_data",
        "grpc_backend_metric_provider",
        "map",
        "slice",
        "//:channel_stack_builder",
        "//:config",
        "//:gpr",
        "//:gpr_platform",
        "//:grpc_base",
        "//:grpc_trace",
        "//:xds_orca_upb",
    ],
 )
 grpc_cc_library(
    name = "polling_resolver",
    srcs = [
--- a/src/core/ext/filters/backend_metrics/backend_metric_filter.cc
+++ b/src/core/ext/filters/backend_metrics/backend_metric_filter.cc
@ -0,0 +1,148 @@
 // Copyright 2023 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.
 #include <grpc/support/port_platform.h>
 #include "src/core/ext/filters/backend_metrics/backend_metric_filter.h"
 #include <inttypes.h>
 #include <limits.h>
 #include <stddef.h>
 #include <functional>
 #include <map>
 #include <memory>
 #include <utility>
 #include "absl/strings/string_view.h"
 #include "upb/upb.h"
 #include "upb/upb.hpp"
 #include "xds/data/orca/v3/orca_load_report.upb.h"
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 #include "src/core/ext/filters/client_channel/lb_policy/backend_metric_data.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/channel/context.h"
 #include "src/core/lib/config/core_configuration.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/promise/context.h"
 #include "src/core/lib/promise/map.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/surface/channel_stack_type.h"
 #include "src/core/lib/transport/metadata_batch.h"
 namespace grpc_core {
 TraceFlag grpc_backend_metric_filter_trace(false, "backend_metric_filter");
 absl::optional<std::string> BackendMetricFilter::MaybeSerializeBackendMetrics(
    BackendMetricProvider* provider) const {
  if (provider == nullptr) return absl::nullopt;
  BackendMetricData data = provider->GetBackendMetricData();
  upb::Arena arena;
  xds_data_orca_v3_OrcaLoadReport* response =
      xds_data_orca_v3_OrcaLoadReport_new(arena.ptr());
  bool has_data = false;
  if (data.cpu_utilization != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_cpu_utilization(response,
                                                        data.cpu_utilization);
    has_data = true;
  }
  if (data.mem_utilization != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_mem_utilization(response,
                                                        data.mem_utilization);
    has_data = true;
  }
  if (data.qps != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_rps_fractional(response, data.qps);
    has_data = true;
  }
  for (const auto& p : data.request_cost) {
    xds_data_orca_v3_OrcaLoadReport_request_cost_set(
        response,
        upb_StringView_FromDataAndSize(p.first.data(), p.first.size()),
        p.second, arena.ptr());
    has_data = true;
  }
  for (const auto& p : data.utilization) {
    xds_data_orca_v3_OrcaLoadReport_utilization_set(
        response,
        upb_StringView_FromDataAndSize(p.first.data(), p.first.size()),
        p.second, arena.ptr());
    has_data = true;
  }
  if (!has_data) {
    return absl::nullopt;
  }
  size_t len;
  char* buf =
      xds_data_orca_v3_OrcaLoadReport_serialize(response, arena.ptr(), &len);
  return std::string(buf, len);
 }
 const grpc_channel_filter BackendMetricFilter::kFilter =
    MakePromiseBasedFilter<BackendMetricFilter, FilterEndpoint::kServer>(
        "backend_metric");
 absl::StatusOr<BackendMetricFilter> BackendMetricFilter::Create(
    const ChannelArgs&, ChannelFilter::Args) {
  return BackendMetricFilter();
 }
 ArenaPromise<ServerMetadataHandle> BackendMetricFilter::MakeCallPromise(
    CallArgs call_args, NextPromiseFactory next_promise_factory) {
  return ArenaPromise<ServerMetadataHandle>(Map(
      next_promise_factory(std::move(call_args)),
      [this](ServerMetadataHandle trailing_metadata) {
        auto* ctx = &GetContext<
            grpc_call_context_element>()[GRPC_CONTEXT_BACKEND_METRIC_PROVIDER];
        if (ctx == nullptr) {
          if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_filter_trace)) {
            gpr_log(GPR_INFO, "[%p] No BackendMetricProvider.", this);
          }
          return trailing_metadata;
        }
        absl::optional<std::string> serialized = MaybeSerializeBackendMetrics(
            reinterpret_cast<BackendMetricProvider*>(ctx->value));
        if (serialized.has_value() && !serialized->empty()) {
          if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_filter_trace)) {
            gpr_log(GPR_INFO,
                    "[%p] Backend metrics serialized. size: %" PRIuPTR, this,
                    serialized->size());
          }
          trailing_metadata->Set(
              EndpointLoadMetricsBinMetadata(),
              Slice::FromCopiedString(std::move(*serialized)));
        } else if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_filter_trace)) {
          gpr_log(GPR_INFO, "[%p] No backend metrics.", this);
        }
        return trailing_metadata;
      }));
 }
 void RegisterBackendMetricFilter(CoreConfiguration::Builder* builder) {
  builder->channel_init()->RegisterStage(
      GRPC_SERVER_CHANNEL, INT_MAX, [](ChannelStackBuilder* builder) {
        if (builder->channel_args().Contains(
                GRPC_ARG_SERVER_CALL_METRIC_RECORDING)) {
          builder->PrependFilter(&BackendMetricFilter::kFilter);
        }
        return true;
      });
 }
 }  // namespace grpc_core
--- a/src/core/ext/filters/backend_metrics/backend_metric_filter.h
+++ b/src/core/ext/filters/backend_metrics/backend_metric_filter.h
@ -0,0 +1,52 @@
 // Copyright 2023 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.
 #ifndef GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_FILTER_H
 #define GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_FILTER_H
 #include <grpc/support/port_platform.h>
 #include <string>
 #include "absl/status/statusor.h"
 #include "absl/types/optional.h"
 #include "src/core/ext/filters/backend_metrics/backend_metric_provider.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_fwd.h"
 #include "src/core/lib/channel/promise_based_filter.h"
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/transport/transport.h"
 namespace grpc_core {
 class BackendMetricFilter : public ChannelFilter {
 public:
  static const grpc_channel_filter kFilter;
  static absl::StatusOr<BackendMetricFilter> Create(const ChannelArgs& args,
                                                    ChannelFilter::Args);
  // Construct a promise for one call.
  ArenaPromise<ServerMetadataHandle> MakeCallPromise(
      CallArgs call_args, NextPromiseFactory next_promise_factory) override;
 private:
  absl::optional<std::string> MaybeSerializeBackendMetrics(
      BackendMetricProvider* provider) const;
 };
 }  // namespace grpc_core
 #endif  // GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_FILTER_H
--- a/src/core/ext/filters/backend_metrics/backend_metric_provider.h
+++ b/src/core/ext/filters/backend_metrics/backend_metric_provider.h
@ -0,0 +1,29 @@
 // Copyright 2023 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.
 #ifndef GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_PROVIDER_H
 #define GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_PROVIDER_H
 namespace grpc_core {
 struct BackendMetricData;
 class BackendMetricProvider {
 public:
  virtual ~BackendMetricProvider() = default;
  virtual BackendMetricData GetBackendMetricData() = 0;
 };
 }  // namespace grpc_core
 #endif  // GRPC_SRC_CORE_EXT_FILTERS_BACKEND_METRICS_BACKEND_METRIC_PROVIDER_H
--- a/src/core/lib/channel/context.h
+++ b/src/core/lib/channel/context.h
@ -45,6 +45,10 @@ typedef enum {
  /// Holds a pointer to ServiceConfigCallData associated with this call.
  GRPC_CONTEXT_SERVICE_CONFIG_CALL_DATA,
  /// Holds a pointer to BackendMetricProvider associated with this call on
  /// the server.
  GRPC_CONTEXT_BACKEND_METRIC_PROVIDER,
  GRPC_CONTEXT_COUNT
 } grpc_context_index;
--- a/src/core/plugin_registry/grpc_plugin_registry.cc
+++ b/src/core/plugin_registry/grpc_plugin_registry.cc
@ -50,6 +50,7 @@ extern void RegisterServiceConfigChannelArgFilter(
 extern void RegisterExtraFilters(CoreConfiguration::Builder* builder);
 extern void RegisterResourceQuota(CoreConfiguration::Builder* builder);
 extern void FaultInjectionFilterRegister(CoreConfiguration::Builder* builder);
 extern void RegisterBackendMetricFilter(CoreConfiguration::Builder* builder);
 extern void RegisterNativeDnsResolver(CoreConfiguration::Builder* builder);
 extern void RegisterAresDnsResolver(CoreConfiguration::Builder* builder);
 extern void RegisterSockaddrResolver(CoreConfiguration::Builder* builder);
@ -110,6 +111,7 @@ void BuildCoreConfiguration(CoreConfiguration::Builder* builder) {
 #endif  // !GRPC_NO_RLS
  // Run last so it gets a consistent location.
  // TODO(ctiller): Is this actually necessary?
  RegisterBackendMetricFilter(builder);
  RegisterSecurityFilters(builder);
  RegisterExtraFilters(builder);
  RegisterBuiltins(builder);
--- a/src/cpp/server/backend_metric_recorder.cc
+++ b/src/cpp/server/backend_metric_recorder.cc
@ -0,0 +1,311 @@
 //
 // Copyright 2023 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.
 //
 #include "src/cpp/server/backend_metric_recorder.h"
 #include <inttypes.h>
 #include <functional>
 #include <memory>
 #include <string>
 #include <type_traits>
 #include <utility>
 #include <grpc/support/log.h>
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include "src/core/ext/filters/client_channel/lb_policy/backend_metric_data.h"
 #include "src/core/lib/debug/trace.h"
 using grpc_core::BackendMetricData;
 namespace {
 // All utilization values must be in [0, 1].
 bool IsUtilizationValid(double utilization) {
  return utilization >= 0.0 && utilization <= 1.0;
 }
 // QPS must be in [0, infy).
 bool IsQpsValid(double qps) { return qps >= 0.0; }
 grpc_core::TraceFlag grpc_backend_metric_trace(false, "backend_metric");
 }  // namespace
 namespace grpc {
 namespace experimental {
 std::unique_ptr<ServerMetricRecorder> ServerMetricRecorder::Create() {
  return std::unique_ptr<ServerMetricRecorder>(new ServerMetricRecorder());
 }
 ServerMetricRecorder::ServerMetricRecorder()
    : metric_state_(std::make_shared<const BackendMetricDataState>()) {}
 void ServerMetricRecorder::UpdateBackendMetricDataState(
    std::function<void(BackendMetricData*)> updater) {
  internal::MutexLock lock(&mu_);
  auto new_state = std::make_shared<BackendMetricDataState>(*metric_state_);
  updater(&new_state->data);
  ++new_state->sequence_number;
  metric_state_ = std::move(new_state);
 }
 void ServerMetricRecorder::SetCpuUtilization(double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] CPU utilization rejected: %f", this, value);
    }
    return;
  }
  UpdateBackendMetricDataState(
      [value](BackendMetricData* data) { data->cpu_utilization = value; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] CPU utilization set: %f", this, value);
  }
 }
 void ServerMetricRecorder::SetMemoryUtilization(double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] Mem utilization rejected: %f", this, value);
    }
    return;
  }
  UpdateBackendMetricDataState(
      [value](BackendMetricData* data) { data->mem_utilization = value; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Mem utilization set: %f", this, value);
  }
 }
 void ServerMetricRecorder::SetQps(double value) {
  if (!IsQpsValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] QPS rejected: %f", this, value);
    }
    return;
  }
  UpdateBackendMetricDataState(
      [value](BackendMetricData* data) { data->qps = value; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] QPS set: %f", this, value);
  }
 }
 void ServerMetricRecorder::SetNamedUtilization(string_ref name, double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] Named utilization rejected: %f name: %s", this,
              value, std::string(name.data(), name.size()).c_str());
    }
    return;
  }
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Named utilization set: %f name: %s", this, value,
            std::string(name.data(), name.size()).c_str());
  }
  UpdateBackendMetricDataState([name, value](BackendMetricData* data) {
    data->utilization[absl::string_view(name.data(), name.size())] = value;
  });
 }
 void ServerMetricRecorder::SetAllNamedUtilization(
    std::map<string_ref, double> named_utilization) {
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] All named utilization updated. size: %" PRIuPTR,
            this, named_utilization.size());
  }
  UpdateBackendMetricDataState(
      [utilization = std::move(named_utilization)](BackendMetricData* data) {
        data->utilization.clear();
        for (const auto& u : utilization) {
          data->utilization[absl::string_view(u.first.data(), u.first.size())] =
              u.second;
        }
      });
 }
 void ServerMetricRecorder::ClearCpuUtilization() {
  UpdateBackendMetricDataState(
      [](BackendMetricData* data) { data->cpu_utilization = -1; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] CPU utilization cleared.", this);
  }
 }
 void ServerMetricRecorder::ClearMemoryUtilization() {
  UpdateBackendMetricDataState(
      [](BackendMetricData* data) { data->mem_utilization = -1; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Mem utilization cleared.", this);
  }
 }
 void ServerMetricRecorder::ClearQps() {
  UpdateBackendMetricDataState([](BackendMetricData* data) { data->qps = -1; });
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] QPS utilization cleared.", this);
  }
 }
 void ServerMetricRecorder::ClearNamedUtilization(string_ref name) {
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Named utilization cleared. name: %s", this,
            std::string(name.data(), name.size()).c_str());
  }
  UpdateBackendMetricDataState([name](BackendMetricData* data) {
    data->utilization.erase(absl::string_view(name.data(), name.size()));
  });
 }
 grpc_core::BackendMetricData ServerMetricRecorder::GetMetrics() const {
  auto result = GetMetricsIfChanged();
  return result->data;
 }
 std::shared_ptr<const ServerMetricRecorder::BackendMetricDataState>
 ServerMetricRecorder::GetMetricsIfChanged() const {
  std::shared_ptr<const BackendMetricDataState> result;
  {
    internal::MutexLock lock(&mu_);
    result = metric_state_;
  }
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    const auto& data = result->data;
    gpr_log(GPR_INFO,
            "[%p] GetMetrics() returned: seq:%" PRIu64
            " cpu:%f mem:%f qps:%f utilization size: %" PRIuPTR,
            this, result->sequence_number, data.cpu_utilization,
            data.mem_utilization, data.qps, data.utilization.size());
  }
  return result;
 }
 }  // namespace experimental
 experimental::CallMetricRecorder&
 BackendMetricState::RecordCpuUtilizationMetric(double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] CPU utilization value rejected: %f", this, value);
    }
    return *this;
  }
  cpu_utilization_.store(value, std::memory_order_relaxed);
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] CPU utilization recorded: %f", this, value);
  }
  return *this;
 }
 experimental::CallMetricRecorder&
 BackendMetricState::RecordMemoryUtilizationMetric(double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] Mem utilization value rejected: %f", this, value);
    }
    return *this;
  }
  mem_utilization_.store(value, std::memory_order_relaxed);
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Mem utilization recorded: %f", this, value);
  }
  return *this;
 }
 experimental::CallMetricRecorder& BackendMetricState::RecordQpsMetric(
    double value) {
  if (!IsQpsValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] QPS value rejected: %f", this, value);
    }
    return *this;
  }
  qps_.store(value, std::memory_order_relaxed);
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] QPS recorded: %f", this, value);
  }
  return *this;
 }
 experimental::CallMetricRecorder& BackendMetricState::RecordUtilizationMetric(
    string_ref name, double value) {
  if (!IsUtilizationValid(value)) {
    if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
      gpr_log(GPR_INFO, "[%p] Utilization value rejected: %s %f", this,
              std::string(name.data(), name.length()).c_str(), value);
    }
    return *this;
  }
  internal::MutexLock lock(&mu_);
  absl::string_view name_sv(name.data(), name.length());
  utilization_[name_sv] = value;
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Utilization recorded: %s %f", this,
            std::string(name_sv).c_str(), value);
  }
  return *this;
 }
 experimental::CallMetricRecorder& BackendMetricState::RecordRequestCostMetric(
    string_ref name, double value) {
  internal::MutexLock lock(&mu_);
  absl::string_view name_sv(name.data(), name.length());
  request_cost_[name_sv] = value;
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO, "[%p] Request cost recorded: %s %f", this,
            std::string(name_sv).c_str(), value);
  }
  return *this;
 }
 BackendMetricData BackendMetricState::GetBackendMetricData() {
  // Merge metrics from the ServerMetricRecorder first since metrics recorded
  // to CallMetricRecorder takes a higher precedence.
  BackendMetricData data;
  if (server_metric_recorder_ != nullptr) {
    data = server_metric_recorder_->GetMetrics();
  }
  // Only overwrite if the value is set i.e. in the valid range.
  const double cpu = cpu_utilization_.load(std::memory_order_relaxed);
  if (IsUtilizationValid(cpu)) {
    data.cpu_utilization = cpu;
  }
  const double mem = mem_utilization_.load(std::memory_order_relaxed);
  if (IsUtilizationValid(mem)) {
    data.mem_utilization = mem;
  }
  const double qps = qps_.load(std::memory_order_relaxed);
  if (IsQpsValid(qps)) {
    data.qps = qps;
  }
  {
    internal::MutexLock lock(&mu_);
    data.utilization = std::move(utilization_);
    data.request_cost = std::move(request_cost_);
  }
  if (GRPC_TRACE_FLAG_ENABLED(grpc_backend_metric_trace)) {
    gpr_log(GPR_INFO,
            "[%p] Backend metric data returned: cpu:%f mem:%f qps:%f "
            "utilization size:%" PRIuPTR " request_cost size:%" PRIuPTR,
            this, data.cpu_utilization, data.mem_utilization, data.qps,
            data.utilization.size(), data.request_cost.size());
  }
  return data;
 }
 }  // namespace grpc
--- a/src/cpp/server/backend_metric_recorder.h
+++ b/src/cpp/server/backend_metric_recorder.h
@ -0,0 +1,81 @@
 //
 //
 // Copyright 2023 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.
 //
 //
 #ifndef GRPC_SRC_CPP_SERVER_BACKEND_METRIC_RECORDER_H
 #define GRPC_SRC_CPP_SERVER_BACKEND_METRIC_RECORDER_H
 #include <stdint.h>
 #include <atomic>
 #include <map>
 #include "absl/base/thread_annotations.h"
 #include "absl/strings/string_view.h"
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/support/string_ref.h>
 #include "src/core/ext/filters/backend_metrics/backend_metric_provider.h"
 #include "src/core/ext/filters/client_channel/lb_policy/backend_metric_data.h"
 namespace grpc {
 namespace experimental {
 // Backend metrics and an associated update sequence number.
 struct ServerMetricRecorder::BackendMetricDataState {
  grpc_core::BackendMetricData data;
  uint64_t sequence_number = 0;
 };
 }  // namespace experimental
 class BackendMetricState : public grpc_core::BackendMetricProvider,
                           public experimental::CallMetricRecorder {
 public:
  // `server_metric_recorder` is optional. When set, GetBackendMetricData()
  // merges metrics from `server_metric_recorder` with metrics recorded to this.
  explicit BackendMetricState(
      experimental::ServerMetricRecorder* server_metric_recorder)
      : server_metric_recorder_(server_metric_recorder) {}
  experimental::CallMetricRecorder& RecordCpuUtilizationMetric(
      double value) override;
  experimental::CallMetricRecorder& RecordMemoryUtilizationMetric(
      double value) override;
  experimental::CallMetricRecorder& RecordQpsMetric(double value) override;
  experimental::CallMetricRecorder& RecordUtilizationMetric(
      string_ref name, double value) override;
  experimental::CallMetricRecorder& RecordRequestCostMetric(
      string_ref name, double value) override;
  // This clears metrics currently recorded. Don't call twice.
  grpc_core::BackendMetricData GetBackendMetricData() override;
 private:
  experimental::ServerMetricRecorder* server_metric_recorder_;
  std::atomic<double> cpu_utilization_{-1.0};
  std::atomic<double> mem_utilization_{-1.0};
  std::atomic<double> qps_{-1.0};
  internal::Mutex mu_;
  std::map<absl::string_view, double> utilization_ ABSL_GUARDED_BY(mu_);
  std::map<absl::string_view, double> request_cost_ ABSL_GUARDED_BY(mu_);
 };
 }  // namespace grpc
 #endif  // GRPC_SRC_CPP_SERVER_BACKEND_METRIC_RECORDER_H
--- a/src/cpp/server/orca/call_metric_recorder.cc
+++ b/src/cpp/server/orca/call_metric_recorder.cc
@ -1,125 +0,0 @@
 //
 // 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.
 //
 #include <stddef.h>
 #include <map>
 #include <string>
 #include <utility>
 #include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 #include "upb/upb.h"
 #include "upb/upb.hpp"
 #include "xds/data/orca/v3/orca_load_report.upb.h"
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/support/string_ref.h>
 #include "src/core/ext/filters/client_channel/lb_policy/backend_metric_data.h"
 #include "src/core/lib/resource_quota/arena.h"
 namespace grpc {
 namespace experimental {
 CallMetricRecorder::CallMetricRecorder(grpc_core::Arena* arena)
    : backend_metric_data_(arena->New<grpc_core::BackendMetricData>()) {}
 CallMetricRecorder::~CallMetricRecorder() {
  backend_metric_data_->~BackendMetricData();
 }
 CallMetricRecorder& CallMetricRecorder::RecordCpuUtilizationMetric(
    double value) {
  internal::MutexLock lock(&mu_);
  backend_metric_data_->cpu_utilization = value;
  return *this;
 }
 CallMetricRecorder& CallMetricRecorder::RecordMemoryUtilizationMetric(
    double value) {
  internal::MutexLock lock(&mu_);
  backend_metric_data_->mem_utilization = value;
  return *this;
 }
 CallMetricRecorder& CallMetricRecorder::RecordQpsMetric(double value) {
  internal::MutexLock lock(&mu_);
  backend_metric_data_->qps = value;
  return *this;
 }
 CallMetricRecorder& CallMetricRecorder::RecordUtilizationMetric(
    grpc::string_ref name, double value) {
  internal::MutexLock lock(&mu_);
  absl::string_view name_sv(name.data(), name.length());
  backend_metric_data_->utilization[name_sv] = value;
  return *this;
 }
 CallMetricRecorder& CallMetricRecorder::RecordRequestCostMetric(
    grpc::string_ref name, double value) {
  internal::MutexLock lock(&mu_);
  absl::string_view name_sv(name.data(), name.length());
  backend_metric_data_->request_cost[name_sv] = value;
  return *this;
 }
 absl::optional<std::string> CallMetricRecorder::CreateSerializedReport() {
  upb::Arena arena;
  internal::MutexLock lock(&mu_);
  bool has_data = backend_metric_data_->cpu_utilization != -1 ||
                  backend_metric_data_->mem_utilization != -1 ||
                  !backend_metric_data_->utilization.empty() ||
                  !backend_metric_data_->request_cost.empty();
  if (!has_data) {
    return absl::nullopt;
  }
  xds_data_orca_v3_OrcaLoadReport* response =
      xds_data_orca_v3_OrcaLoadReport_new(arena.ptr());
  if (backend_metric_data_->cpu_utilization != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_cpu_utilization(
        response, backend_metric_data_->cpu_utilization);
  }
  if (backend_metric_data_->mem_utilization != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_mem_utilization(
        response, backend_metric_data_->mem_utilization);
  }
  if (backend_metric_data_->qps != -1) {
    xds_data_orca_v3_OrcaLoadReport_set_rps_fractional(
        response, backend_metric_data_->qps);
  }
  for (const auto& p : backend_metric_data_->request_cost) {
    xds_data_orca_v3_OrcaLoadReport_request_cost_set(
        response,
        upb_StringView_FromDataAndSize(p.first.data(), p.first.size()),
        p.second, arena.ptr());
  }
  for (const auto& p : backend_metric_data_->utilization) {
    xds_data_orca_v3_OrcaLoadReport_utilization_set(
        response,
        upb_StringView_FromDataAndSize(p.first.data(), p.first.size()),
        p.second, arena.ptr());
  }
  size_t buf_length;
  char* buf = xds_data_orca_v3_OrcaLoadReport_serialize(response, arena.ptr(),
                                                        &buf_length);
  return std::string(buf, buf_length);
 }
 }  // namespace experimental
 }  // namespace grpc
--- a/src/cpp/server/orca/orca_interceptor.cc
+++ b/src/cpp/server/orca/orca_interceptor.cc
@ -1,76 +0,0 @@
 //
 // 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.
 //
 #include "src/cpp/server/orca/orca_interceptor.h"
 #include <algorithm>
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 #include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/server_builder.h>
 #include <grpcpp/server_context.h>
 #include "src/core/lib/transport/metadata_batch.h"
 namespace grpc {
 namespace experimental {
 void OrcaServerInterceptor::Intercept(InterceptorBatchMethods* methods) {
  if (methods->QueryInterceptionHookPoint(
          InterceptionHookPoints::POST_RECV_INITIAL_METADATA)) {
    auto context = info_->server_context();
    context->CreateCallMetricRecorder();
  } else if (methods->QueryInterceptionHookPoint(
                 InterceptionHookPoints::PRE_SEND_STATUS)) {
    auto trailers = methods->GetSendTrailingMetadata();
    if (trailers != nullptr) {
      auto context = info_->server_context();
      auto* recorder = context->call_metric_recorder_;
      auto serialized = recorder->CreateSerializedReport();
      if (serialized.has_value() && !serialized->empty()) {
        std::string key =
            std::string(grpc_core::EndpointLoadMetricsBinMetadata::key());
        trailers->emplace(
            std::make_pair(std::move(key), std::move(serialized.value())));
      }
    }
  }
  methods->Proceed();
 }
 Interceptor* OrcaServerInterceptorFactory::CreateServerInterceptor(
    ServerRpcInfo* info) {
  return new OrcaServerInterceptor(info);
 }
 void OrcaServerInterceptorFactory::Register(grpc::ServerBuilder* builder) {
  builder->internal_interceptor_creators_.push_back(
      std::make_unique<OrcaServerInterceptorFactory>());
 }
 void EnableCallMetricRecording(grpc::ServerBuilder* builder) {
  OrcaServerInterceptorFactory::Register(builder);
 }
 }  // namespace experimental
 }  // namespace grpc
--- a/src/cpp/server/orca/orca_interceptor.h
+++ b/src/cpp/server/orca/orca_interceptor.h
@ -1,49 +0,0 @@
 //
 // 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.
 //
 #ifndef GRPC_SRC_CPP_SERVER_ORCA_ORCA_INTERCEPTOR_H
 #define GRPC_SRC_CPP_SERVER_ORCA_ORCA_INTERCEPTOR_H
 #include <grpcpp/support/interceptor.h>
 #include <grpcpp/support/server_interceptor.h>
 namespace grpc {
 class ServerBuilder;
 namespace experimental {
 class ServerRpcInfo;
 class OrcaServerInterceptor : public Interceptor {
 public:
  explicit OrcaServerInterceptor(ServerRpcInfo* info) : info_(info) {}
  void Intercept(InterceptorBatchMethods* methods) override;
 private:
  ServerRpcInfo* info_;
 };
 class OrcaServerInterceptorFactory : public ServerInterceptorFactoryInterface {
 public:
  static void Register(ServerBuilder* builder);
  Interceptor* CreateServerInterceptor(ServerRpcInfo* info) override;
 };
 }  // namespace experimental
 }  // namespace grpc
 #endif  // GRPC_SRC_CPP_SERVER_ORCA_ORCA_INTERCEPTOR_H
--- a/src/cpp/server/orca/orca_service.cc
+++ b/src/cpp/server/orca/orca_service.cc
@ -15,13 +15,14 @@
 //
 #include <stddef.h>
 #include <stdint.h>
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include "absl/base/thread_annotations.h"
 #include "absl/strings/string_view.h"
 #include "absl/time/time.h"
 #include "absl/types/optional.h"
 #include "google/protobuf/duration.upb.h"
@ -33,6 +34,7 @@
 #include <grpc/event_engine/event_engine.h>
 #include <grpc/support/log.h>
 #include <grpcpp/ext/orca_service.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/impl/rpc_method.h>
 #include <grpcpp/impl/rpc_service_method.h>
 #include <grpcpp/impl/server_callback_handlers.h>
@ -43,12 +45,14 @@
 #include <grpcpp/support/slice.h>
 #include <grpcpp/support/status.h>
 #include "src/core/ext/filters/client_channel/lb_policy/backend_metric_data.h"
 #include "src/core/lib/event_engine/default_event_engine.h"
 #include "src/core/lib/gprpp/debug_location.h"
 #include "src/core/lib/gprpp/ref_counted.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/gprpp/time.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/cpp/server/backend_metric_recorder.h"
 namespace grpc {
 namespace experimental {
@ -166,8 +170,11 @@ class OrcaService::Reactor : public ServerWriteReactor<ByteBuffer>,
 // OrcaService
 //
-OrcaService::OrcaService(OrcaService::Options options)
+OrcaService::OrcaService(ServerMetricRecorder* const server_metric_recorder,
-    : min_report_duration_(options.min_report_duration) {
+                         Options options)
    : server_metric_recorder_(server_metric_recorder),
      min_report_duration_(options.min_report_duration) {
  GPR_ASSERT(server_metric_recorder_ != nullptr);
  AddMethod(new internal::RpcServiceMethod(
      "/xds.service.orca.v3.OpenRcaService/StreamCoreMetrics",
      internal::RpcMethod::SERVER_STREAMING, /*handler=*/nullptr));
@ -178,88 +185,38 @@ OrcaService::OrcaService(OrcaService::Options options)
             }));
 }
 void OrcaService::SetCpuUtilization(double cpu_utilization) {
  grpc::internal::MutexLock lock(&mu_);
  cpu_utilization_ = cpu_utilization;
  response_slice_.reset();
 }
 void OrcaService::DeleteCpuUtilization() {
  grpc::internal::MutexLock lock(&mu_);
  cpu_utilization_ = -1;
  response_slice_.reset();
 }
 void OrcaService::SetMemoryUtilization(double memory_utilization) {
  grpc::internal::MutexLock lock(&mu_);
  memory_utilization_ = memory_utilization;
  response_slice_.reset();
 }
 void OrcaService::DeleteMemoryUtilization() {
  grpc::internal::MutexLock lock(&mu_);
  memory_utilization_ = -1;
  response_slice_.reset();
 }
 void OrcaService::SetQps(double qps) {
  grpc::internal::MutexLock lock(&mu_);
  qps_ = qps;
  response_slice_.reset();
 }
 void OrcaService::DeleteQps() {
  grpc::internal::MutexLock lock(&mu_);
  qps_ = -1;
  response_slice_.reset();
 }
 void OrcaService::SetNamedUtilization(std::string name, double utilization) {
  grpc::internal::MutexLock lock(&mu_);
  named_utilization_[std::move(name)] = utilization;
  response_slice_.reset();
 }
 void OrcaService::DeleteNamedUtilization(const std::string& name) {
  grpc::internal::MutexLock lock(&mu_);
  named_utilization_.erase(name);
  response_slice_.reset();
 }
 void OrcaService::SetAllNamedUtilization(
    std::map<std::string, double> named_utilization) {
  grpc::internal::MutexLock lock(&mu_);
  named_utilization_ = std::move(named_utilization);
  response_slice_.reset();
 }
 Slice OrcaService::GetOrCreateSerializedResponse() {
  grpc::internal::MutexLock lock(&mu_);
-  if (!response_slice_.has_value()) {
+  std::shared_ptr<const ServerMetricRecorder::BackendMetricDataState> result =
      server_metric_recorder_->GetMetricsIfChanged();
  if (!response_slice_seq_.has_value() ||
      *response_slice_seq_ != result->sequence_number) {
    const auto& data = result->data;
    upb::Arena arena;
    xds_data_orca_v3_OrcaLoadReport* response =
        xds_data_orca_v3_OrcaLoadReport_new(arena.ptr());
-    if (cpu_utilization_ != -1) {
+    if (data.cpu_utilization != -1) {
      xds_data_orca_v3_OrcaLoadReport_set_cpu_utilization(response,
-                                                          cpu_utilization_);
+                                                          data.cpu_utilization);
    }
-    if (memory_utilization_ != -1) {
+    if (data.mem_utilization != -1) {
      xds_data_orca_v3_OrcaLoadReport_set_mem_utilization(response,
-                                                          memory_utilization_);
+                                                          data.mem_utilization);
    }
-    if (qps_ != -1) {
+    if (data.qps != -1) {
-      xds_data_orca_v3_OrcaLoadReport_set_rps_fractional(response, qps_);
+      xds_data_orca_v3_OrcaLoadReport_set_rps_fractional(response, data.qps);
    }
-    for (const auto& p : named_utilization_) {
+    for (const auto& u : data.utilization) {
      xds_data_orca_v3_OrcaLoadReport_utilization_set(
          response,
-          upb_StringView_FromDataAndSize(p.first.data(), p.first.size()),
+          upb_StringView_FromDataAndSize(u.first.data(), u.first.size()),
-          p.second, arena.ptr());
+          u.second, arena.ptr());
    }
    size_t buf_length;
    char* buf = xds_data_orca_v3_OrcaLoadReport_serialize(response, arena.ptr(),
                                                          &buf_length);
    response_slice_.emplace(buf, buf_length);
    response_slice_seq_ = result->sequence_number;
  }
  return Slice(*response_slice_);
 }
--- a/src/cpp/server/server_builder.cc
+++ b/src/cpp/server/server_builder.cc
@ -21,7 +21,6 @@
 #include <string.h>
 #include <algorithm>
 #include <iterator>
 #include <memory>
 #include <string>
 #include <utility>
@ -158,6 +157,13 @@ void ServerBuilder::experimental_type::SetAuthorizationPolicyProvider(
  builder_->authorization_provider_ = std::move(provider);
 }
 void ServerBuilder::experimental_type::EnableCallMetricRecording(
    experimental::ServerMetricRecorder* server_metric_recorder) {
  builder_->AddChannelArgument(GRPC_ARG_SERVER_CALL_METRIC_RECORDING, 1);
  GPR_ASSERT(builder_->server_metric_recorder_ == nullptr);
  builder_->server_metric_recorder_ = server_metric_recorder;
 }
 ServerBuilder& ServerBuilder::SetOption(
    std::unique_ptr<ServerBuilderOption> option) {
  options_.push_back(std::move(option));
@ -355,18 +361,11 @@ std::unique_ptr<grpc::Server> ServerBuilder::BuildAndStart() {
    gpr_log(GPR_INFO, "Callback server.");
  }
  // Merge the application and internal interceptors together.
  // Internal interceptors go first.
  auto creators = std::move(internal_interceptor_creators_);
  creators.insert(creators.end(),
                  std::make_move_iterator(interceptor_creators_.begin()),
                  std::make_move_iterator(interceptor_creators_.end()));
  std::unique_ptr<grpc::Server> server(new grpc::Server(
      &args, sync_server_cqs, sync_server_settings_.min_pollers,
      sync_server_settings_.max_pollers, sync_server_settings_.cq_timeout_msec,
      std::move(acceptors_), server_config_fetcher_, resource_quota_,
-      std::move(creators)));
+      std::move(interceptor_creators_), server_metric_recorder_));
  ServerInitializer* initializer = server->initializer();
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@ -155,6 +155,8 @@ ServerInterface::BaseAsyncRequest::BaseAsyncRequest(
  interceptor_methods_.SetCall(&call_wrapper_);
  interceptor_methods_.SetReverse();
  call_cq_->RegisterAvalanching();  // This op will trigger more ops
  call_metric_recording_enabled_ = server_->call_metric_recording_enabled();
  server_metric_recorder_ = server_->server_metric_recorder();
 }
 ServerInterface::BaseAsyncRequest::~BaseAsyncRequest() {
@ -170,7 +172,8 @@ bool ServerInterface::BaseAsyncRequest::FinalizeResult(void** tag,
    }
    return true;
  }
-  context_->set_call(call_);
+  context_->set_call(call_, call_metric_recording_enabled_,
                     server_metric_recorder_);
  context_->cq_ = call_cq_;
  if (call_wrapper_.call() == nullptr) {
    // Fill it since it is empty.
@ -408,7 +411,8 @@ class Server::SyncRequest final : public grpc::internal::CompletionQueueTag {
        call_, server_, &cq_, server_->max_receive_message_size(),
        ctx_->ctx.set_server_rpc_info(method_->name(), method_->method_type(),
                                      server_->interceptor_creators_));
-    ctx_->ctx.set_call(call_);
+    ctx_->ctx.set_call(call_, server_->call_metric_recording_enabled(),
                       server_->server_metric_recorder());
    ctx_->ctx.cq_ = &cq_;
    request_metadata_.count = 0;
@ -636,7 +640,9 @@ class Server::CallbackRequest final
      }
      // Bind the call, deadline, and metadata from what we got
-      req_->ctx_->set_call(req_->call_);
+      req_->ctx_->set_call(req_->call_,
                           req_->server_->call_metric_recording_enabled(),
                           req_->server_->server_metric_recorder());
      req_->ctx_->cq_ = req_->cq_;
      req_->ctx_->BindDeadlineAndMetadata(req_->deadline_,
                                          &req_->request_metadata_);
@ -878,7 +884,8 @@ Server::Server(
    grpc_resource_quota* server_rq,
    std::vector<
        std::unique_ptr<grpc::experimental::ServerInterceptorFactoryInterface>>
-        interceptor_creators)
+        interceptor_creators,
    experimental::ServerMetricRecorder* server_metric_recorder)
    : acceptors_(std::move(acceptors)),
      interceptor_creators_(std::move(interceptor_creators)),
      max_receive_message_size_(INT_MIN),
@ -888,7 +895,8 @@ Server::Server(
      shutdown_notified_(false),
      server_(nullptr),
      server_initializer_(new ServerInitializer(this)),
-      health_check_service_disabled_(false) {
+      health_check_service_disabled_(false),
      server_metric_recorder_(server_metric_recorder) {
  gpr_once_init(&grpc::g_once_init_callbacks, grpc::InitGlobalCallbacks);
  global_callbacks_ = grpc::g_callbacks;
  global_callbacks_->UpdateArguments(args);
@ -935,6 +943,10 @@ Server::Server(
        strcmp(channel_args.args[i].key, GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH)) {
      max_receive_message_size_ = channel_args.args[i].value.integer;
    }
    if (0 == strcmp(channel_args.args[i].key,
                    GRPC_ARG_SERVER_CALL_METRIC_RECORDING)) {
      call_metric_recording_enabled_ = channel_args.args[i].value.integer;
    }
  }
  server_ = grpc_server_create(&channel_args, nullptr);
  grpc_server_set_config_fetcher(server_, server_config_fetcher);
--- a/src/cpp/server/server_context.cc
+++ b/src/cpp/server/server_context.cc
@ -41,6 +41,7 @@
 #include <grpc/support/time.h>
 #include <grpcpp/completion_queue.h>
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/impl/call.h>
 #include <grpcpp/impl/call_op_set.h>
 #include <grpcpp/impl/call_op_set_interface.h>
@ -54,11 +55,13 @@
 #include <grpcpp/support/server_interceptor.h>
 #include <grpcpp/support/string_ref.h>
 #include "src/core/lib/channel/context.h"
 #include "src/core/lib/gprpp/crash.h"
 #include "src/core/lib/gprpp/ref_counted.h"
 #include "src/core/lib/gprpp/sync.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/surface/call.h"
 #include "src/cpp/server/backend_metric_recorder.h"
 namespace grpc {
@ -398,10 +401,16 @@ void ServerContextBase::SetLoadReportingCosts(
  }
 }
-void ServerContextBase::CreateCallMetricRecorder() {
+void ServerContextBase::CreateCallMetricRecorder(
    experimental::ServerMetricRecorder* server_metric_recorder) {
  if (call_.call == nullptr) return;
  GPR_ASSERT(call_metric_recorder_ == nullptr);
  grpc_core::Arena* arena = grpc_call_get_arena(call_.call);
-  call_metric_recorder_ = arena->New<experimental::CallMetricRecorder>(arena);
+  auto* backend_metric_state =
      arena->New<BackendMetricState>(server_metric_recorder);
  call_metric_recorder_ = backend_metric_state;
  grpc_call_context_set(call_.call, GRPC_CONTEXT_BACKEND_METRIC_PROVIDER,
                        backend_metric_state, nullptr);
 }
 grpc::string_ref ServerContextBase::ExperimentalGetAuthority() const {
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@ -15,6 +15,7 @@
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc_core_dependencies.py.template`!!!
 CORE_SOURCE_FILES = [
    'src/core/ext/filters/backend_metrics/backend_metric_filter.cc',
    'src/core/ext/filters/census/grpc_context.cc',
    'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
    'src/core/ext/filters/channel_idle/idle_filter_state.cc',
--- a/test/cpp/end2end/BUILD
+++ b/test/cpp/end2end/BUILD
@ -495,7 +495,8 @@ grpc_cc_test(
        "//:gpr",
        "//:grpc",
        "//:grpc++",
-        "//:grpcpp_orca_interceptor",
+        "//:grpcpp_backend_metric_recorder",
        "//:grpcpp_call_metric_recorder",
        "//:grpcpp_orca_service",
        "//src/core:channel_args",
        "//src/proto/grpc/testing:echo_messages_proto",
@ -946,6 +947,8 @@ grpc_cc_test(
    ],
    deps = [
        "//:grpc++",
        "//:grpcpp_backend_metric_recorder",
        "//:grpcpp_call_metric_recorder",
        "//:grpcpp_orca_service",
        "//src/proto/grpc/testing/xds/v3:orca_service_proto",
        "//test/core/util:grpc_test_util",
--- a/test/cpp/end2end/client_lb_end2end_test.cc
+++ b/test/cpp/end2end/client_lb_end2end_test.cc
@ -41,6 +41,7 @@
 #include <grpcpp/create_channel.h>
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/ext/orca_service.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/health_check_service_interface.h>
 #include <grpcpp/impl/sync.h>
 #include <grpcpp/server.h>
@ -94,44 +95,29 @@ class MyTestServiceImpl : public TestServiceImpl {
      ++request_count_;
    }
    AddClient(context->peer());
    absl::optional<xds::data::orca::v3::OrcaLoadReport> load_report;
    {
      grpc_core::MutexLock lock(&load_report_mu_);
      load_report = load_report_;
    }
    if (request->has_param() && request->param().has_backend_metrics()) {
      if (!load_report.has_value()) load_report.emplace();
      const auto& request_metrics = request->param().backend_metrics();
      auto* recorder = context->ExperimentalGetCallMetricRecorder();
      EXPECT_NE(recorder, nullptr);
      // Do not record when zero since it indicates no test per-call report.
      if (request_metrics.cpu_utilization() > 0) {
-        load_report->set_cpu_utilization(request_metrics.cpu_utilization());
+        recorder->RecordCpuUtilizationMetric(request_metrics.cpu_utilization());
      }
      if (request_metrics.mem_utilization() > 0) {
-        load_report->set_mem_utilization(request_metrics.mem_utilization());
+        recorder->RecordMemoryUtilizationMetric(
            request_metrics.mem_utilization());
      }
      if (request_metrics.rps_fractional() > 0) {
-        load_report->set_rps_fractional(request_metrics.rps_fractional());
+        recorder->RecordQpsMetric(request_metrics.rps_fractional());
      }
      for (const auto& p : request_metrics.request_cost()) {
        (*load_report->mutable_request_cost())[p.first] = p.second;
      }
      for (const auto& p : request_metrics.utilization()) {
        (*load_report->mutable_utilization())[p.first] = p.second;
      }
    }
    if (load_report.has_value()) {
      auto* recorder = context->ExperimentalGetCallMetricRecorder();
      EXPECT_NE(recorder, nullptr);
      recorder->RecordCpuUtilizationMetric(load_report->cpu_utilization())
          .RecordMemoryUtilizationMetric(load_report->mem_utilization())
          .RecordQpsMetric(load_report->rps_fractional());
      for (const auto& p : load_report->request_cost()) {
        char* key = static_cast<char*>(
            grpc_call_arena_alloc(context->c_call(), p.first.size() + 1));
        strncpy(key, p.first.data(), p.first.size());
        key[p.first.size()] = '\0';
        recorder->RecordRequestCostMetric(key, p.second);
      }
-      for (const auto& p : load_report->utilization()) {
+      for (const auto& p : request_metrics.utilization()) {
        char* key = static_cast<char*>(
            grpc_call_arena_alloc(context->c_call(), p.first.size() + 1));
        strncpy(key, p.first.data(), p.first.size());
@ -142,7 +128,7 @@ class MyTestServiceImpl : public TestServiceImpl {
    return TestServiceImpl::Echo(context, request, response);
  }
-  int request_count() {
+  size_t request_count() {
    grpc_core::MutexLock lock(&mu_);
    return request_count_;
  }
@ -157,15 +143,6 @@ class MyTestServiceImpl : public TestServiceImpl {
    return clients_;
  }
  // TODO(roth): Once the backend utilization APIs are updated, change
  // this to use those instead of manually constructing the data for
  // each call.
  void SetLoadReport(
      absl::optional<xds::data::orca::v3::OrcaLoadReport> load_report) {
    grpc_core::MutexLock lock(&load_report_mu_);
    load_report_ = std::move(load_report);
  }
 private:
  void AddClient(const std::string& client) {
    grpc_core::MutexLock lock(&clients_mu_);
@ -173,14 +150,10 @@ class MyTestServiceImpl : public TestServiceImpl {
  }
  grpc_core::Mutex mu_;
-  int request_count_ ABSL_GUARDED_BY(&mu_) = 0;
+  size_t request_count_ ABSL_GUARDED_BY(&mu_) = 0;
  grpc_core::Mutex clients_mu_;
  std::set<std::string> clients_ ABSL_GUARDED_BY(&clients_mu_);
  grpc_core::Mutex load_report_mu_;
  absl::optional<xds::data::orca::v3::OrcaLoadReport> load_report_
      ABSL_GUARDED_BY(&load_report_mu_);
 };
 class FakeResolverResponseGeneratorWrapper {
@ -278,16 +251,6 @@ class ClientLbEnd2endTest : public ::testing::Test {
        creds_(new SecureChannelCredentials(
            grpc_fake_transport_security_credentials_create())) {}
  static void SetUpTestSuite() {
    // Make the backup poller poll very frequently in order to pick up
    // updates from all the subchannels's FDs.
    GPR_GLOBAL_CONFIG_SET(grpc_client_channel_backup_poll_interval_ms, 1);
 #if TARGET_OS_IPHONE
    // Workaround Apple CFStream bug
    grpc_core::SetEnv("grpc_cfstream", "0");
 #endif
  }
  void SetUp() override {
    grpc_init();
    bool localhost_resolves_to_ipv4 = false;
@ -418,14 +381,16 @@ class ClientLbEnd2endTest : public ::testing::Test {
      const grpc_core::DebugLocation& debug_location,
      const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub,
      std::function<bool(const Status&)> continue_predicate,
-      int timeout_ms = 15000) {
+      EchoRequest* request_ptr = nullptr, int timeout_ms = 15000) {
    absl::Time deadline = absl::InfiniteFuture();
    if (timeout_ms != 0) {
      deadline = absl::Now() +
                 (absl::Milliseconds(timeout_ms) * grpc_test_slowdown_factor());
    }
    while (true) {
-      Status status = SendRpc(stub);
+      Status status =
          SendRpc(stub, /*response=*/nullptr, /*timeout_ms=*/1000,
                  /*wait_for_ready=*/false, /*request=*/request_ptr);
      if (!continue_predicate(status)) return;
      EXPECT_LE(absl::Now(), deadline)
          << debug_location.file() << ":" << debug_location.line();
@ -437,6 +402,7 @@ class ClientLbEnd2endTest : public ::testing::Test {
    const int port_;
    std::unique_ptr<Server> server_;
    MyTestServiceImpl service_;
    std::unique_ptr<experimental::ServerMetricRecorder> server_metric_recorder_;
    experimental::OrcaService orca_service_;
    std::unique_ptr<std::thread> thread_;
@ -447,7 +413,11 @@ class ClientLbEnd2endTest : public ::testing::Test {
    explicit ServerData(int port = 0)
        : port_(port > 0 ? port : grpc_pick_unused_port_or_die()),
-          orca_service_(experimental::OrcaService::Options()) {}
+          server_metric_recorder_(experimental::ServerMetricRecorder::Create()),
          orca_service_(
              server_metric_recorder_.get(),
              experimental::OrcaService::Options().set_min_report_duration(
                  absl::Seconds(0.1))) {}
    void Start(const std::string& server_host) {
      gpr_log(GPR_INFO, "starting server on port %d", port_);
@ -466,12 +436,13 @@ class ClientLbEnd2endTest : public ::testing::Test {
      std::ostringstream server_address;
      server_address << server_host << ":" << port_;
      ServerBuilder builder;
      experimental::EnableCallMetricRecording(&builder);
      std::shared_ptr<ServerCredentials> creds(new SecureServerCredentials(
          grpc_fake_transport_security_server_credentials_create()));
      builder.AddListeningPort(server_address.str(), std::move(creds));
      builder.RegisterService(&service_);
      builder.RegisterService(&orca_service_);
      grpc::ServerBuilder::experimental_type(&builder)
          .EnableCallMetricRecording(server_metric_recorder_.get());
      server_ = builder.BuildAndStart();
      grpc_core::MutexLock lock(&mu_);
      server_ready_ = true;
@ -2552,8 +2523,12 @@ TEST_F(ClientLbInterceptTrailingMetadataTest, BackendMetricData) {
  (*request_cost)["foo"] = 0.8;
  (*request_cost)["bar"] = 1.4;
  auto* utilization = load_report.mutable_utilization();
-  (*utilization)["baz"] = 1.1;
+  (*utilization)["baz"] = 1.0;
  (*utilization)["quux"] = 0.9;
  // This will be rejected.
  (*utilization)["out_of_range_invalid"] = 1.1;
  auto expected = load_report;
  expected.mutable_utilization()->erase("out_of_range_invalid");
  auto response_generator = BuildResolverResponseGenerator();
  auto channel =
      BuildChannel("intercept_trailing_metadata_lb", response_generator);
@ -2565,19 +2540,19 @@ TEST_F(ClientLbInterceptTrailingMetadataTest, BackendMetricData) {
    ASSERT_TRUE(actual.has_value());
    // TODO(roth): Change this to use EqualsProto() once that becomes
    // available in OSS.
-    EXPECT_EQ(actual->cpu_utilization(), load_report.cpu_utilization());
+    EXPECT_EQ(actual->cpu_utilization(), expected.cpu_utilization());
-    EXPECT_EQ(actual->mem_utilization(), load_report.mem_utilization());
+    EXPECT_EQ(actual->mem_utilization(), expected.mem_utilization());
-    EXPECT_EQ(actual->rps_fractional(), load_report.rps_fractional());
+    EXPECT_EQ(actual->rps_fractional(), expected.rps_fractional());
-    EXPECT_EQ(actual->request_cost().size(), load_report.request_cost().size());
+    EXPECT_EQ(actual->request_cost().size(), expected.request_cost().size());
    for (const auto& p : actual->request_cost()) {
-      auto it = load_report.request_cost().find(p.first);
+      auto it = expected.request_cost().find(p.first);
-      ASSERT_NE(it, load_report.request_cost().end());
+      ASSERT_NE(it, expected.request_cost().end());
      EXPECT_EQ(it->second, p.second);
    }
-    EXPECT_EQ(actual->utilization().size(), load_report.utilization().size());
+    EXPECT_EQ(actual->utilization().size(), expected.utilization().size());
    for (const auto& p : actual->utilization()) {
-      auto it = load_report.utilization().find(p.first);
+      auto it = expected.utilization().find(p.first);
-      ASSERT_NE(it, load_report.utilization().end());
+      ASSERT_NE(it, expected.utilization().end());
      EXPECT_EQ(it->second, p.second);
    }
  }
@ -2736,10 +2711,10 @@ TEST_F(OobBackendMetricTest, Basic) {
  StartServers(1);
  // Set initial backend metric data on server.
  constexpr char kMetricName[] = "foo";
-  servers_[0]->orca_service_.SetCpuUtilization(0.1);
+  servers_[0]->server_metric_recorder_->SetCpuUtilization(0.1);
-  servers_[0]->orca_service_.SetMemoryUtilization(0.2);
+  servers_[0]->server_metric_recorder_->SetMemoryUtilization(0.2);
-  servers_[0]->orca_service_.SetQps(0.3);
+  servers_[0]->server_metric_recorder_->SetQps(0.3);
-  servers_[0]->orca_service_.SetNamedUtilization(kMetricName, 0.4);
+  servers_[0]->server_metric_recorder_->SetNamedUtilization(kMetricName, 0.4);
  // Start client.
  auto response_generator = BuildResolverResponseGenerator();
  auto channel = BuildChannel("oob_backend_metric_test_lb", response_generator);
@ -2751,6 +2726,7 @@ TEST_F(OobBackendMetricTest, Basic) {
  EXPECT_EQ("oob_backend_metric_test_lb",
            channel->GetLoadBalancingPolicyName());
  // Check report seen by client.
  bool report_seen = false;
  for (size_t i = 0; i < 5; ++i) {
    auto report = GetBackendMetricReport();
    if (report.has_value()) {
@ -2761,19 +2737,22 @@ TEST_F(OobBackendMetricTest, Basic) {
      EXPECT_THAT(
          report->second.utilization(),
          ::testing::UnorderedElementsAre(::testing::Pair(kMetricName, 0.4)));
      report_seen = true;
      break;
    }
    gpr_sleep_until(grpc_timeout_seconds_to_deadline(1));
  }
  ASSERT_TRUE(report_seen);
  // Now update the utilization data on the server.
  // Note that the server may send a new report while we're updating these,
  // so we set them in reverse order, so that we know we'll get all new
  // data once we see a report with the new CPU utilization value.
-  servers_[0]->orca_service_.SetNamedUtilization(kMetricName, 0.7);
+  servers_[0]->server_metric_recorder_->SetNamedUtilization(kMetricName, 0.7);
-  servers_[0]->orca_service_.SetQps(0.6);
+  servers_[0]->server_metric_recorder_->SetQps(0.6);
-  servers_[0]->orca_service_.SetMemoryUtilization(0.5);
+  servers_[0]->server_metric_recorder_->SetMemoryUtilization(0.5);
-  servers_[0]->orca_service_.SetCpuUtilization(0.4);
+  servers_[0]->server_metric_recorder_->SetCpuUtilization(0.4);
  // Wait for client to see new report.
  report_seen = false;
  for (size_t i = 0; i < 5; ++i) {
    auto report = GetBackendMetricReport();
    if (report.has_value()) {
@ -2785,11 +2764,13 @@ TEST_F(OobBackendMetricTest, Basic) {
        EXPECT_THAT(
            report->second.utilization(),
            ::testing::UnorderedElementsAre(::testing::Pair(kMetricName, 0.7)));
        report_seen = true;
        break;
      }
    }
    gpr_sleep_until(grpc_timeout_seconds_to_deadline(1));
  }
  ASSERT_TRUE(report_seen);
 }
 //
@ -2882,97 +2863,125 @@ TEST_F(ControlPlaneStatusRewritingTest, RewritesFromConfigSelector) {
 // WeightedRoundRobinTest
 //
-using WeightedRoundRobinTest = ClientLbEnd2endTest;
+const char kServiceConfigPerCall[] =
    "{\n"
    "  \"loadBalancingConfig\": [\n"
    "    {\"weighted_round_robin_experimental\": {\n"
    "      \"blackoutPeriod\": \"0s\",\n"
    "      \"weightUpdatePeriod\": \"0.1s\"\n"
    "    }}\n"
    "  ]\n"
    "}";
 const char kServiceConfigOob[] =
    "{\n"
    "  \"loadBalancingConfig\": [\n"
    "    {\"weighted_round_robin_experimental\": {\n"
    "      \"blackoutPeriod\": \"0s\",\n"
    "      \"weightUpdatePeriod\": \"0.1s\",\n"
    "      \"enableOobLoadReport\": true\n"
    "    }}\n"
    "  ]\n"
    "}";
 class WeightedRoundRobinTest : public ClientLbEnd2endTest {
 protected:
  void ExpectWeightedRoundRobinPicks(
      const grpc_core::DebugLocation& location,
      const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub,
      const std::vector<size_t>& expected_weights, size_t total_passes = 3,
      EchoRequest* request_ptr = nullptr) {
    GPR_ASSERT(expected_weights.size() == servers_.size());
    size_t total_picks_per_pass = 0;
    for (size_t picks : expected_weights) {
      total_picks_per_pass += picks;
    }
    size_t num_picks = 0;
    size_t num_passes = 0;
    SendRpcsUntil(
        location, stub,
        [&](const Status&) {
          if (++num_picks == total_picks_per_pass) {
            bool match = true;
            for (size_t i = 0; i < expected_weights.size(); ++i) {
              if (servers_[i]->service_.request_count() !=
                  expected_weights[i]) {
                match = false;
                break;
              }
            }
            if (match) {
              if (++num_passes == total_passes) return false;
            } else {
              num_passes = 0;
            }
            num_picks = 0;
            ResetCounters();
          }
          return true;
        },
        request_ptr);
  }
 };
-TEST_F(WeightedRoundRobinTest, Basic) {
+TEST_F(WeightedRoundRobinTest, CallAndServerMetric) {
  const int kNumServers = 3;
  StartServers(kNumServers);
-  // Tell each server to report the appropriate CPU utilization.
+  // Report server metrics that should give 1:2:4 WRR picks.
-  xds::data::orca::v3::OrcaLoadReport load_report;
+  servers_[0]->server_metric_recorder_->SetCpuUtilization(0.9);
-  load_report.set_rps_fractional(100);
+  servers_[0]->server_metric_recorder_->SetQps(9);
-  load_report.set_cpu_utilization(0.9);
+  servers_[1]->server_metric_recorder_->SetCpuUtilization(0.3);
-  servers_[0]->service_.SetLoadReport(load_report);
+  servers_[1]->server_metric_recorder_->SetQps(6);
-  load_report.set_cpu_utilization(0.3);
+  servers_[2]->server_metric_recorder_->SetCpuUtilization(0.3);
-  servers_[1]->service_.SetLoadReport(load_report);
+  servers_[2]->server_metric_recorder_->SetQps(12);
  servers_[2]->service_.SetLoadReport(load_report);
  // Create channel.
  auto response_generator = BuildResolverResponseGenerator();
  auto channel = BuildChannel("", response_generator);
  auto stub = BuildStub(channel);
-  const char kServiceConfig[] =
+  response_generator.SetNextResolution(GetServersPorts(),
-      "{\n"
+                                       kServiceConfigPerCall);
-      "  \"loadBalancingConfig\": [\n"
+  // Send requests with per-call reported QPS set to 100.
-      "    {\"weighted_round_robin_experimental\": {\n"
+  // This should override per-server QPS above and give 1:3:3 WRR picks.
-      "      \"blackoutPeriod\": \"0s\"\n"
+  EchoRequest request;
-      "    }}\n"
+  request.mutable_param()->mutable_backend_metrics()->set_rps_fractional(100);
-      "  ]\n"
+  ExpectWeightedRoundRobinPicks(DEBUG_LOCATION, stub,
-      "}";
+                                /*expected_weights=*/{1, 3, 3},
-  response_generator.SetNextResolution(GetServersPorts(), kServiceConfig);
+                                /*total_passes=*/3, &request);
-  // Wait for the right set of WRR picks.
+  // Now send requests without per-call reported QPS.
-  size_t num_picks = 0;
+  // This should change WRR picks back to 1:2:4.
-  SendRpcsUntil(DEBUG_LOCATION, stub, [&](const Status&) {
+  ExpectWeightedRoundRobinPicks(DEBUG_LOCATION, stub,
-    if (++num_picks == 7) {
+                                /*expected_weights=*/{1, 2, 4});
      gpr_log(GPR_INFO, "request counts: %d %d %d",
              servers_[0]->service_.request_count(),
              servers_[1]->service_.request_count(),
              servers_[2]->service_.request_count());
      if (servers_[0]->service_.request_count() == 1 &&
          servers_[1]->service_.request_count() == 3 &&
          servers_[2]->service_.request_count() == 3) {
        return false;
      }
      num_picks = 0;
      ResetCounters();
    }
    return true;
  });
  // Check LB policy name for the channel.
  EXPECT_EQ("weighted_round_robin_experimental",
            channel->GetLoadBalancingPolicyName());
 }
-TEST_F(WeightedRoundRobinTest, OobReporting) {
+class WeightedRoundRobinParamTest
    : public WeightedRoundRobinTest,
      public ::testing::WithParamInterface<const char*> {};
 INSTANTIATE_TEST_SUITE_P(WeightedRoundRobin, WeightedRoundRobinParamTest,
                         ::testing::Values(kServiceConfigPerCall,
                                           kServiceConfigOob));
 TEST_P(WeightedRoundRobinParamTest, Basic) {
  const int kNumServers = 3;
  StartServers(kNumServers);
-  // Tell each server to report the appropriate CPU utilization.
+  // Report server metrics that should give 1:3:3 WRR picks.
-  servers_[0]->orca_service_.SetCpuUtilization(0.9);
+  servers_[0]->server_metric_recorder_->SetCpuUtilization(0.9);
-  servers_[0]->orca_service_.SetQps(100);
+  servers_[0]->server_metric_recorder_->SetQps(100);
-  servers_[1]->orca_service_.SetCpuUtilization(0.3);
+  servers_[1]->server_metric_recorder_->SetCpuUtilization(0.3);
-  servers_[1]->orca_service_.SetQps(100);
+  servers_[1]->server_metric_recorder_->SetQps(100);
-  servers_[2]->orca_service_.SetCpuUtilization(0.3);
+  servers_[2]->server_metric_recorder_->SetCpuUtilization(0.3);
-  servers_[2]->orca_service_.SetQps(100);
+  servers_[2]->server_metric_recorder_->SetQps(100);
  // Create channel.
  auto response_generator = BuildResolverResponseGenerator();
  auto channel = BuildChannel("", response_generator);
  auto stub = BuildStub(channel);
-  const char kServiceConfig[] =
+  response_generator.SetNextResolution(GetServersPorts(), GetParam());
      "{\n"
      "  \"loadBalancingConfig\": [\n"
      "    {\"weighted_round_robin_experimental\": {\n"
      "      \"blackoutPeriod\": \"0s\",\n"
      "      \"enableOobLoadReport\": true\n"
      "    }}\n"
      "  ]\n"
      "}";
  response_generator.SetNextResolution(GetServersPorts(), kServiceConfig);
  // Wait for the right set of WRR picks.
-  size_t num_picks = 0;
+  ExpectWeightedRoundRobinPicks(DEBUG_LOCATION, stub,
-  SendRpcsUntil(DEBUG_LOCATION, stub, [&](const Status&) {
+                                /*expected_weights=*/{1, 3, 3});
    if (++num_picks == 7) {
      gpr_log(GPR_INFO, "request counts: %d %d %d",
              servers_[0]->service_.request_count(),
              servers_[1]->service_.request_count(),
              servers_[2]->service_.request_count());
      if (servers_[0]->service_.request_count() == 1 &&
          servers_[1]->service_.request_count() == 3 &&
          servers_[2]->service_.request_count() == 3) {
        return false;
      }
      num_picks = 0;
      ResetCounters();
    }
    return true;
  });
  // Check LB policy name for the channel.
  EXPECT_EQ("weighted_round_robin_experimental",
            channel->GetLoadBalancingPolicyName());
@ -2984,6 +2993,13 @@ TEST_F(WeightedRoundRobinTest, OobReporting) {
 int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);
  // Make the backup poller poll very frequently in order to pick up
  // updates from all the subchannels's FDs.
  GPR_GLOBAL_CONFIG_SET(grpc_client_channel_backup_poll_interval_ms, 1);
 #if TARGET_OS_IPHONE
  // Workaround Apple CFStream bug
  grpc_core::SetEnv("grpc_cfstream", "0");
 #endif
  grpc::testing::TestEnvironment env(&argc, argv);
  grpc_init();
  grpc::testing::ConnectionAttemptInjector::Init();
--- a/test/cpp/end2end/orca_service_end2end_test.cc
+++ b/test/cpp/end2end/orca_service_end2end_test.cc
@ -24,7 +24,9 @@
 #include <grpcpp/channel.h>
 #include <grpcpp/client_context.h>
 #include <grpcpp/create_channel.h>
 #include <grpcpp/ext/call_metric_recorder.h>
 #include <grpcpp/ext/orca_service.h>
 #include <grpcpp/ext/server_metric_recorder.h>
 #include <grpcpp/server.h>
 #include <grpcpp/server_builder.h>
 #include <grpcpp/server_context.h>
@ -44,6 +46,7 @@ namespace testing {
 namespace {
 using experimental::OrcaService;
 using experimental::ServerMetricRecorder;
 class OrcaServiceEnd2endTest : public ::testing::Test {
 protected:
@ -91,8 +94,10 @@ class OrcaServiceEnd2endTest : public ::testing::Test {
  };
  OrcaServiceEnd2endTest()
-      : orca_service_(OrcaService::Options().set_min_report_duration(
+      : server_metric_recorder_(ServerMetricRecorder::Create()),
-            absl::ZeroDuration())) {
+        orca_service_(server_metric_recorder_.get(),
                      OrcaService::Options().set_min_report_duration(
                          absl::ZeroDuration())) {
    std::string server_address =
        absl::StrCat("localhost:", grpc_pick_unused_port_or_die());
    ServerBuilder builder;
@ -107,6 +112,7 @@ class OrcaServiceEnd2endTest : public ::testing::Test {
  ~OrcaServiceEnd2endTest() override { server_->Shutdown(); }
  std::string server_address_;
  std::unique_ptr<ServerMetricRecorder> server_metric_recorder_;
  OrcaService orca_service_;
  std::unique_ptr<Server> server_;
  std::unique_ptr<OpenRcaService::Stub> stub_;
@ -140,24 +146,24 @@ TEST_F(OrcaServiceEnd2endTest, Basic) {
    EXPECT_THAT(response.utilization(), ::testing::UnorderedElementsAre());
  });
  // Now set CPU utilization on the server.
-  orca_service_.SetCpuUtilization(0.5);
+  server_metric_recorder_->SetCpuUtilization(0.5);
  ReadResponses([](const OrcaLoadReport& response) {
    EXPECT_EQ(response.cpu_utilization(), 0.5);
    EXPECT_EQ(response.mem_utilization(), 0);
    EXPECT_THAT(response.utilization(), ::testing::UnorderedElementsAre());
  });
  // Update CPU utilization and set memory utilization.
-  orca_service_.SetCpuUtilization(0.8);
+  server_metric_recorder_->SetCpuUtilization(0.8);
-  orca_service_.SetMemoryUtilization(0.4);
+  server_metric_recorder_->SetMemoryUtilization(0.4);
  ReadResponses([](const OrcaLoadReport& response) {
    EXPECT_EQ(response.cpu_utilization(), 0.8);
    EXPECT_EQ(response.mem_utilization(), 0.4);
    EXPECT_THAT(response.utilization(), ::testing::UnorderedElementsAre());
  });
  // Unset CPU and memory utilization and set a named utilization.
-  orca_service_.DeleteCpuUtilization();
+  server_metric_recorder_->ClearCpuUtilization();
-  orca_service_.DeleteMemoryUtilization();
+  server_metric_recorder_->ClearMemoryUtilization();
-  orca_service_.SetNamedUtilization(kMetricName1, 0.3);
+  server_metric_recorder_->SetNamedUtilization(kMetricName1, 0.3);
  ReadResponses([&](const OrcaLoadReport& response) {
    EXPECT_EQ(response.cpu_utilization(), 0);
    EXPECT_EQ(response.mem_utilization(), 0);
@ -166,9 +172,9 @@ TEST_F(OrcaServiceEnd2endTest, Basic) {
        ::testing::UnorderedElementsAre(::testing::Pair(kMetricName1, 0.3)));
  });
  // Unset the previous named utilization and set two new ones.
-  orca_service_.DeleteNamedUtilization(kMetricName1);
+  server_metric_recorder_->ClearNamedUtilization(kMetricName1);
-  orca_service_.SetNamedUtilization(kMetricName2, 0.2);
+  server_metric_recorder_->SetNamedUtilization(kMetricName2, 0.2);
-  orca_service_.SetNamedUtilization(kMetricName3, 0.1);
+  server_metric_recorder_->SetNamedUtilization(kMetricName3, 0.1);
  ReadResponses([&](const OrcaLoadReport& response) {
    EXPECT_EQ(response.cpu_utilization(), 0);
    EXPECT_EQ(response.mem_utilization(), 0);
@ -178,7 +184,7 @@ TEST_F(OrcaServiceEnd2endTest, Basic) {
                                        ::testing::Pair(kMetricName3, 0.1)));
  });
  // Replace the entire named metric map at once.
-  orca_service_.SetAllNamedUtilization(
+  server_metric_recorder_->SetAllNamedUtilization(
      {{kMetricName2, 0.5}, {kMetricName4, 0.9}});
  ReadResponses([&](const OrcaLoadReport& response) {
    EXPECT_EQ(response.cpu_utilization(), 0);
--- a/test/cpp/end2end/xds/BUILD
+++ b/test/cpp/end2end/xds/BUILD
@ -59,7 +59,6 @@ grpc_cc_library(
        "//:grpc",
        "//:grpc++",
        "//:grpc_resolver_fake",
        "//:grpcpp_orca_interceptor",
        "//src/proto/grpc/testing:echo_messages_proto",
        "//src/proto/grpc/testing:echo_proto",
        "//src/proto/grpc/testing/duplicate:echo_duplicate_proto",
--- a/test/cpp/end2end/xds/xds_end2end_test_lib.cc
+++ b/test/cpp/end2end/xds/xds_end2end_test_lib.cc
@ -251,7 +251,7 @@ XdsEnd2endTest::BackendServerThread::Credentials() {
 void XdsEnd2endTest::BackendServerThread::RegisterAllServices(
    ServerBuilder* builder) {
-  experimental::EnableCallMetricRecording(builder);
+  ServerBuilder::experimental_type(builder).EnableCallMetricRecording();
  builder->RegisterService(&backend_service_);
  builder->RegisterService(&backend_service1_);
  builder->RegisterService(&backend_service2_);
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@ -952,6 +952,7 @@ include/grpcpp/create_channel_binder.h \
 include/grpcpp/create_channel_posix.h \
 include/grpcpp/ext/call_metric_recorder.h \
 include/grpcpp/ext/health_check_service_server_builder_option.h \
 include/grpcpp/ext/server_metric_recorder.h \
 include/grpcpp/generic/async_generic_service.h \
 include/grpcpp/generic/generic_stub.h \
 include/grpcpp/grpcpp.h \
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@ -952,6 +952,7 @@ include/grpcpp/create_channel_binder.h \
 include/grpcpp/create_channel_posix.h \
 include/grpcpp/ext/call_metric_recorder.h \
 include/grpcpp/ext/health_check_service_server_builder_option.h \
 include/grpcpp/ext/server_metric_recorder.h \
 include/grpcpp/generic/async_generic_service.h \
 include/grpcpp/generic/generic_stub.h \
 include/grpcpp/grpcpp.h \
@ -1071,6 +1072,9 @@ include/grpcpp/support/time.h \
 include/grpcpp/support/validate_service_config.h \
 include/grpcpp/version_info.h \
 include/grpcpp/xds_server_builder.h \
 src/core/ext/filters/backend_metrics/backend_metric_filter.cc \
 src/core/ext/filters/backend_metrics/backend_metric_filter.h \
 src/core/ext/filters/backend_metrics/backend_metric_provider.h \
 src/core/ext/filters/census/grpc_context.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.h \
@ -2724,6 +2728,8 @@ src/cpp/common/tls_credentials_options.cc \
 src/cpp/common/validate_service_config.cc \
 src/cpp/common/version_cc.cc \
 src/cpp/server/async_generic_service.cc \
 src/cpp/server/backend_metric_recorder.cc \
 src/cpp/server/backend_metric_recorder.h \
 src/cpp/server/channel_argument_option.cc \
 src/cpp/server/create_default_thread_pool.cc \
 src/cpp/server/dynamic_thread_pool.h \
@ -2734,7 +2740,6 @@ src/cpp/server/health/default_health_check_service.h \
 src/cpp/server/health/health_check_service.cc \
 src/cpp/server/health/health_check_service_server_builder_option.cc \
 src/cpp/server/insecure_server_credentials.cc \
 src/cpp/server/orca/call_metric_recorder.cc \
 src/cpp/server/secure_server_credentials.cc \
 src/cpp/server/secure_server_credentials.h \
 src/cpp/server/server_builder.cc \
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@ -877,6 +877,9 @@ include/grpc/support/time.h \
 include/grpc/support/workaround_list.h \
 src/core/README.md \
 src/core/ext/README.md \
 src/core/ext/filters/backend_metrics/backend_metric_filter.cc \
 src/core/ext/filters/backend_metrics/backend_metric_filter.h \
 src/core/ext/filters/backend_metrics/backend_metric_provider.h \
 src/core/ext/filters/census/grpc_context.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.h \