LRS changes for federation (#28504)

* Passing xds server object instead of just a string name

* Adding xds server to policy

* Refactor ToJson

* Using XdsServer for load reporting

* code review comments

* fixing code review comments

* Taking care of lifetime of the XdsServer key

* code review comments

* Fixing channel_state storage and re-run tests (1 assert hit)

* Checking for server in the bootstrap file

* Adding LRS test

* adding a bootstrap file ToJson and parse test

* fixing code review comments

* fixing code review comments.

* fixing test

* break out the federation lrs test

* Fixed last bit of code review comments

* fixing error message to be more precise

src/core/ext/filters/client_channel/lb_policy/xds/cds.cc

@@ -366,9 +366,9 @@ bool CdsLb::GenerateDiscoveryMechanismForCluster(
       GPR_ASSERT(0);
       break;
   }
-  if (state.update->lrs_load_reporting_server_name.has_value()) {
+  if (state.update->lrs_load_reporting_server.has_value()) {
-    mechanism["lrsLoadReportingServerName"] =
+    mechanism["lrsLoadReportingServer"] =
-        state.update->lrs_load_reporting_server_name.value();
+        state.update->lrs_load_reporting_server->ToJson();
   }
   discovery_mechanisms->emplace_back(std::move(mechanism));
   return true;

src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc

@@ -119,14 +119,13 @@ class XdsClusterImplLbConfig : public LoadBalancingPolicy::Config {
   XdsClusterImplLbConfig(
       RefCountedPtr<LoadBalancingPolicy::Config> child_policy,
       std::string cluster_name, std::string eds_service_name,
-      absl::optional<std::string> lrs_load_reporting_server_name,
+      absl::optional<XdsBootstrap::XdsServer> lrs_load_reporting_server,
       uint32_t max_concurrent_requests,
       RefCountedPtr<XdsEndpointResource::DropConfig> drop_config)
       : child_policy_(std::move(child_policy)),
         cluster_name_(std::move(cluster_name)),
         eds_service_name_(std::move(eds_service_name)),
-        lrs_load_reporting_server_name_(
+        lrs_load_reporting_server_(std::move(lrs_load_reporting_server)),
-            std::move(lrs_load_reporting_server_name)),
         max_concurrent_requests_(max_concurrent_requests),
         drop_config_(std::move(drop_config)) {}
 
@@ -137,8 +136,9 @@ class XdsClusterImplLbConfig : public LoadBalancingPolicy::Config {
   }
   const std::string& cluster_name() const { return cluster_name_; }
   const std::string& eds_service_name() const { return eds_service_name_; }
-  const absl::optional<std::string>& lrs_load_reporting_server_name() const {
+  const absl::optional<XdsBootstrap::XdsServer>& lrs_load_reporting_server()
-    return lrs_load_reporting_server_name_;
+      const {
+    return lrs_load_reporting_server_;
   };
   uint32_t max_concurrent_requests() const { return max_concurrent_requests_; }
   RefCountedPtr<XdsEndpointResource::DropConfig> drop_config() const {
@@ -149,7 +149,7 @@ class XdsClusterImplLbConfig : public LoadBalancingPolicy::Config {
   RefCountedPtr<LoadBalancingPolicy::Config> child_policy_;
   std::string cluster_name_;
   std::string eds_service_name_;
-  absl::optional<std::string> lrs_load_reporting_server_name_;
+  absl::optional<XdsBootstrap::XdsServer> lrs_load_reporting_server_;
   uint32_t max_concurrent_requests_;
   RefCountedPtr<XdsEndpointResource::DropConfig> drop_config_;
 };
@@ -462,10 +462,19 @@ void XdsClusterImplLb::UpdateLocked(UpdateArgs args) {
   config_ = std::move(args.config);
   // On initial update, create drop stats.
   if (is_initial_update) {
-    if (config_->lrs_load_reporting_server_name().has_value()) {
+    if (config_->lrs_load_reporting_server().has_value()) {
       drop_stats_ = xds_client_->AddClusterDropStats(
-          config_->lrs_load_reporting_server_name().value(),
+          config_->lrs_load_reporting_server().value(), config_->cluster_name(),
-          config_->cluster_name(), config_->eds_service_name());
+          config_->eds_service_name());
+      if (drop_stats_ == nullptr) {
+        gpr_log(GPR_ERROR,
+                "[xds_cluster_impl_lb %p] Failed to get cluster drop stats for "
+                "LRS server %s, cluster %s, EDS service name %s, load "
+                "reporting for drops will not be done.",
+                this, config_->lrs_load_reporting_server()->server_uri.c_str(),
+                config_->cluster_name().c_str(),
+                config_->eds_service_name().c_str());
+      }
     }
     call_counter_ = g_call_counter_map->GetOrCreate(
         config_->cluster_name(), config_->eds_service_name());
@@ -475,8 +484,8 @@ void XdsClusterImplLb::UpdateLocked(UpdateArgs args) {
     // swapped out if that happens.
     GPR_ASSERT(config_->cluster_name() == old_config->cluster_name());
     GPR_ASSERT(config_->eds_service_name() == old_config->eds_service_name());
-    GPR_ASSERT(config_->lrs_load_reporting_server_name() ==
+    GPR_ASSERT(config_->lrs_load_reporting_server() ==
-               old_config->lrs_load_reporting_server_name());
+               old_config->lrs_load_reporting_server());
   }
   // Update picker if max_concurrent_requests has changed.
   if (is_initial_update || config_->max_concurrent_requests() !=
@@ -575,7 +584,7 @@ RefCountedPtr<SubchannelInterface> XdsClusterImplLb::Helper::CreateSubchannel(
   if (xds_cluster_impl_policy_->shutting_down_) return nullptr;
   // If load reporting is enabled, wrap the subchannel such that it
   // includes the locality stats object, which will be used by the EdsPicker.
-  if (xds_cluster_impl_policy_->config_->lrs_load_reporting_server_name()
+  if (xds_cluster_impl_policy_->config_->lrs_load_reporting_server()
           .has_value()) {
     RefCountedPtr<XdsLocalityName> locality_name;
     auto* attribute = address.GetAttribute(kXdsLocalityNameAttributeKey);
@@ -586,16 +595,27 @@ RefCountedPtr<SubchannelInterface> XdsClusterImplLb::Helper::CreateSubchannel(
     }
     RefCountedPtr<XdsClusterLocalityStats> locality_stats =
         xds_cluster_impl_policy_->xds_client_->AddClusterLocalityStats(
-            *xds_cluster_impl_policy_->config_
+            xds_cluster_impl_policy_->config_->lrs_load_reporting_server()
-                 ->lrs_load_reporting_server_name(),
+                .value(),
             xds_cluster_impl_policy_->config_->cluster_name(),
             xds_cluster_impl_policy_->config_->eds_service_name(),
             std::move(locality_name));
+    if (locality_stats != nullptr) {
       return MakeRefCounted<StatsSubchannelWrapper>(
           xds_cluster_impl_policy_->channel_control_helper()->CreateSubchannel(
               std::move(address), args),
           std::move(locality_stats));
     }
+    gpr_log(GPR_ERROR,
+            "[xds_cluster_impl_lb %p] Failed to get locality stats object for "
+            "LRS server %s, cluster %s, EDS service name %s; load reports will "
+            "not be generated (not wrapping subchannel)",
+            this,
+            xds_cluster_impl_policy_->config_->lrs_load_reporting_server()
+                ->server_uri.c_str(),
+            xds_cluster_impl_policy_->config_->cluster_name().c_str(),
+            xds_cluster_impl_policy_->config_->eds_service_name().c_str());
+  }
   // Load reporting not enabled, so don't wrap the subchannel.
   return xds_cluster_impl_policy_->channel_control_helper()->CreateSubchannel(
       std::move(address), args);
@@ -715,14 +735,21 @@ class XdsClusterImplLbFactory : public LoadBalancingPolicyFactory {
       }
     }
     // LRS load reporting server name.
-    absl::optional<std::string> lrs_load_reporting_server_name;
+    absl::optional<XdsBootstrap::XdsServer> lrs_load_reporting_server;
-    it = json.object_value().find("lrsLoadReportingServerName");
+    it = json.object_value().find("lrsLoadReportingServer");
     if (it != json.object_value().end()) {
-      if (it->second.type() != Json::Type::STRING) {
+      if (it->second.type() != Json::Type::OBJECT) {
         error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:lrsLoadReportingServerName error:type should be string"));
+            "field:lrsLoadReportingServer error:type should be object"));
       } else {
-        lrs_load_reporting_server_name = it->second.string_value();
+        grpc_error_handle parser_error;
+        lrs_load_reporting_server = XdsBootstrap::XdsServer::Parse(
+            it->second.object_value(), &parser_error);
+        if (parser_error != GRPC_ERROR_NONE) {
+          error_list.push_back(GRPC_ERROR_CREATE_FROM_CPP_STRING(
+              absl::StrCat("errors parsing lrs_load_reporting_server")));
+          error_list.push_back(parser_error);
+        }
       }
     }
     // Max concurrent requests.
@@ -758,7 +785,7 @@ class XdsClusterImplLbFactory : public LoadBalancingPolicyFactory {
     }
     return MakeRefCounted<XdsClusterImplLbConfig>(
         std::move(child_policy), std::move(cluster_name),
-        std::move(eds_service_name), std::move(lrs_load_reporting_server_name),
+        std::move(eds_service_name), std::move(lrs_load_reporting_server),
         max_concurrent_requests, std::move(drop_config));
   }
 

src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_resolver.cc

@@ -34,6 +34,7 @@
 #include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
+#include "src/core/ext/xds/xds_bootstrap.h"
 #include "src/core/ext/xds/xds_channel_args.h"
 #include "src/core/ext/xds/xds_client.h"
 #include "src/core/ext/xds/xds_client_stats.h"
@@ -65,7 +66,7 @@ class XdsClusterResolverLbConfig : public LoadBalancingPolicy::Config {
  public:
   struct DiscoveryMechanism {
     std::string cluster_name;
-    absl::optional<std::string> lrs_load_reporting_server_name;
+    absl::optional<XdsBootstrap::XdsServer> lrs_load_reporting_server;
     uint32_t max_concurrent_requests;
     enum DiscoveryMechanismType {
       EDS,
@@ -77,8 +78,7 @@ class XdsClusterResolverLbConfig : public LoadBalancingPolicy::Config {
 
     bool operator==(const DiscoveryMechanism& other) const {
       return (cluster_name == other.cluster_name &&
-              lrs_load_reporting_server_name ==
+              lrs_load_reporting_server == other.lrs_load_reporting_server &&
-                  other.lrs_load_reporting_server_name &&
               max_concurrent_requests == other.max_concurrent_requests &&
               type == other.type &&
               eds_service_name == other.eds_service_name &&
@@ -887,10 +887,10 @@ XdsClusterResolverLb::CreateChildPolicyConfigLocked() {
       xds_cluster_impl_config["edsServiceName"] = std::string(lrs_key.second);
     }
     if (config_->discovery_mechanisms()[discovery_index]
-            .lrs_load_reporting_server_name.has_value()) {
+            .lrs_load_reporting_server.has_value()) {
-      xds_cluster_impl_config["lrsLoadReportingServerName"] =
+      xds_cluster_impl_config["lrsLoadReportingServer"] =
           config_->discovery_mechanisms()[discovery_index]
-              .lrs_load_reporting_server_name.value();
+              .lrs_load_reporting_server->ToJson();
     }
     Json locality_picking_policy = Json::Array{Json::Object{
         {"xds_cluster_impl_experimental", std::move(xds_cluster_impl_config)},
@@ -1151,14 +1151,20 @@ class XdsClusterResolverLbFactory : public LoadBalancingPolicyFactory {
       discovery_mechanism->cluster_name = it->second.string_value();
     }
     // LRS load reporting server name.
-    it = json.object_value().find("lrsLoadReportingServerName");
+    it = json.object_value().find("lrsLoadReportingServer");
     if (it != json.object_value().end()) {
-      if (it->second.type() != Json::Type::STRING) {
+      if (it->second.type() != Json::Type::OBJECT) {
         error_list.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
-            "field:lrsLoadReportingServerName error:type should be string"));
+            "field:lrsLoadReportingServer error:type should be object"));
       } else {
-        discovery_mechanism->lrs_load_reporting_server_name.emplace(
+        grpc_error_handle parse_error;
-            it->second.string_value());
+        discovery_mechanism->lrs_load_reporting_server.emplace(
+            XdsBootstrap::XdsServer::Parse(it->second, &parse_error));
+        if (parse_error != GRPC_ERROR_NONE) {
+          error_list.push_back(GRPC_ERROR_CREATE_FROM_CPP_STRING(
+              absl::StrCat("errors parsing lrs_load_reporting_server")));
+          error_list.push_back(parse_error);
+        }
       }
     }
     // Max concurrent requests.

src/core/ext/xds/upb_utils.h

@@ -27,6 +27,7 @@
 #include "upb/upb.hpp"
 
 #include "src/core/ext/xds/certificate_provider_store.h"
+#include "src/core/ext/xds/xds_bootstrap.h"
 #include "src/core/lib/debug/trace.h"
 
 namespace grpc_core {
@@ -38,6 +39,7 @@ class XdsClient;
 // passing through XdsApi code, maybe via the AdsResponseParser.
 struct XdsEncodingContext {
   XdsClient* client;  // Used only for logging. Unsafe for dereferencing.
+  const XdsBootstrap::XdsServer& server;
   TraceFlag* tracer;
   upb_symtab* symtab;
   upb_arena* arena;

src/core/ext/xds/xds_api.cc

@@ -277,6 +277,7 @@ grpc_slice XdsApi::CreateAdsRequest(
     bool populate_node) {
   upb::Arena arena;
   const XdsEncodingContext context = {client_,
+                                      server,
                                       tracer_,
                                       symtab_->ptr(),
                                       arena.ptr(),
@@ -356,6 +357,7 @@ absl::Status XdsApi::ParseAdsResponse(const XdsBootstrap::XdsServer& server,
                                       AdsResponseParserInterface* parser) {
   upb::Arena arena;
   const XdsEncodingContext context = {client_,
+                                      server,
                                       tracer_,
                                       symtab_->ptr(),
                                       arena.ptr(),
@@ -431,6 +433,7 @@ grpc_slice XdsApi::CreateLrsInitialRequest(
     const XdsBootstrap::XdsServer& server) {
   upb::Arena arena;
   const XdsEncodingContext context = {client_,
+                                      server,
                                       tracer_,
                                       symtab_->ptr(),
                                       arena.ptr(),
@@ -505,9 +508,16 @@ void LocalityStatsPopulate(
 grpc_slice XdsApi::CreateLrsRequest(
     ClusterLoadReportMap cluster_load_report_map) {
   upb::Arena arena;
-  const XdsEncodingContext context = {
+  // The xDS server info is not actually needed here, so we seed it with an
-      client_,     tracer_, symtab_->ptr(),
+  // empty value.
-      arena.ptr(), false,   certificate_provider_definition_map_};
+  XdsBootstrap::XdsServer empty_server;
+  const XdsEncodingContext context = {client_,
+                                      empty_server,
+                                      tracer_,
+                                      symtab_->ptr(),
+                                      arena.ptr(),
+                                      false,
+                                      certificate_provider_definition_map_};
   // Create a request.
   envoy_service_load_stats_v3_LoadStatsRequest* request =
       envoy_service_load_stats_v3_LoadStatsRequest_new(arena.ptr());
@@ -629,9 +639,16 @@ std::string XdsApi::AssembleClientConfig(
   // Fill-in the node information
   auto* node = envoy_service_status_v3_ClientConfig_mutable_node(client_config,
                                                                  arena.ptr());
-  const XdsEncodingContext context = {
+  // The xDS server info is not actually needed here, so we seed it with an
-      client_,     tracer_, symtab_->ptr(),
+  // empty value.
-      arena.ptr(), true,    certificate_provider_definition_map_};
+  XdsBootstrap::XdsServer empty_server;
+  const XdsEncodingContext context = {client_,
+                                      empty_server,
+                                      tracer_,
+                                      symtab_->ptr(),
+                                      arena.ptr(),
+                                      true,
+                                      certificate_provider_definition_map_};
   PopulateNode(context, node_, build_version_, user_agent_name_,
                user_agent_version_, node);
   // Dump each resource.

src/core/ext/xds/xds_bootstrap.cc

@@ -137,6 +137,25 @@ XdsBootstrap::XdsServer XdsBootstrap::XdsServer::Parse(
   return server;
 }
 
+Json::Object XdsBootstrap::XdsServer::ToJson() const {
+  Json::Object channel_creds_json{{"type", channel_creds_type}};
+  if (channel_creds_config.type() != Json::Type::JSON_NULL) {
+    channel_creds_json["config"] = channel_creds_config;
+  }
+  Json::Object json{
+      {"server_uri", server_uri},
+      {"channel_creds", Json::Array{std::move(channel_creds_json)}},
+  };
+  if (!server_features.empty()) {
+    Json::Array server_features_json;
+    for (auto& feature : server_features) {
+      server_features_json.emplace_back(feature);
+    }
+    json["server_features"] = std::move(server_features_json);
+  }
+  return json;
+}
+
 bool XdsBootstrap::XdsServer::ShouldUseV3() const {
   return server_features.find("xds_v3") != server_features.end();
 }
@@ -244,6 +263,17 @@ const XdsBootstrap::Authority* XdsBootstrap::LookupAuthority(
   return nullptr;
 }
 
+bool XdsBootstrap::XdsServerExists(
+    const XdsBootstrap::XdsServer& server) const {
+  if (server == servers_[0]) return true;
+  for (auto& authority : authorities_) {
+    for (auto& xds_server : authority.second.xds_servers) {
+      if (server == xds_server) return true;
+    }
+  }
+  return false;
+}
+
 grpc_error_handle XdsBootstrap::ParseXdsServerList(
     Json* json, absl::InlinedVector<XdsServer, 1>* servers) {
   std::vector<grpc_error_handle> error_list;

src/core/ext/xds/xds_bootstrap.h

@@ -58,6 +58,13 @@ class XdsBootstrap {
 
     static XdsServer Parse(const Json& json, grpc_error_handle* error);
 
+    bool operator==(const XdsServer& other) const {
+      return (server_uri == other.server_uri &&
+              channel_creds_type == other.channel_creds_type &&
+              channel_creds_config == other.channel_creds_config &&
+              server_features == other.server_features);
+    }
+
     bool operator<(const XdsServer& other) const {
       if (server_uri < other.server_uri) return true;
       if (channel_creds_type < other.channel_creds_type) return true;
@@ -68,6 +75,8 @@ class XdsBootstrap {
       return false;
     }
 
+    Json::Object ToJson() const;
+
     bool ShouldUseV3() const;
   };
 
@@ -105,6 +114,8 @@ class XdsBootstrap {
       const {
     return certificate_providers_;
   }
+  // A util method to check that an xds server exists in this bootstrap file.
+  bool XdsServerExists(const XdsServer& server) const;
 
  private:
   grpc_error_handle ParseXdsServerList(

src/core/ext/xds/xds_client.cc

@@ -581,7 +581,10 @@ void XdsClient::ChannelState::MaybeStartLrsCall() {
       WeakRef(DEBUG_LOCATION, "ChannelState+lrs")));
 }
 
-void XdsClient::ChannelState::StopLrsCall() { lrs_calld_.reset(); }
+void XdsClient::ChannelState::StopLrsCallLocked() {
+  xds_client_->xds_load_report_server_map_.erase(server_);
+  lrs_calld_.reset();
+}
 
 void XdsClient::ChannelState::StartConnectivityWatchLocked() {
   ClientChannel* client_channel = ClientChannel::GetFromChannel(channel_);
@@ -1385,15 +1388,19 @@ bool LoadReportCountersAreZero(const XdsApi::ClusterLoadReportMap& snapshot) {
 bool XdsClient::ChannelState::LrsCallState::Reporter::SendReportLocked() {
   // Construct snapshot from all reported stats.
   XdsApi::ClusterLoadReportMap snapshot =
-      xds_client()->BuildLoadReportSnapshotLocked(parent_->send_all_clusters_,
+      xds_client()->BuildLoadReportSnapshotLocked(parent_->chand()->server_,
+                                                  parent_->send_all_clusters_,
                                                   parent_->cluster_names_);
   // Skip client load report if the counters were all zero in the last
   // report and they are still zero in this one.
   const bool old_val = last_report_counters_were_zero_;
   last_report_counters_were_zero_ = LoadReportCountersAreZero(snapshot);
   if (old_val && last_report_counters_were_zero_) {
-    if (xds_client()->load_report_map_.empty()) {
+    auto it = xds_client()->xds_load_report_server_map_.find(
-      parent_->chand()->StopLrsCall();
+        parent_->chand()->server_);
+    if (it == xds_client()->xds_load_report_server_map_.end() ||
+        it->second.load_report_map.empty()) {
+      it->second.channel_state->StopLrsCallLocked();
       return true;
     }
     ScheduleNextReportLocked();
@@ -1439,8 +1446,11 @@ bool XdsClient::ChannelState::LrsCallState::Reporter::OnReportDoneLocked(
   grpc_byte_buffer_destroy(parent_->send_message_payload_);
   parent_->send_message_payload_ = nullptr;
   // If there are no more registered stats to report, cancel the call.
-  if (xds_client()->load_report_map_.empty()) {
+  auto it =
-    parent_->chand()->StopLrsCall();
+      xds_client()->xds_load_report_server_map_.find(parent_->chand()->server_);
+  if (it == xds_client()->xds_load_report_server_map_.end() ||
+      it->second.load_report_map.empty()) {
+    it->second.channel_state->StopLrsCallLocked();
     GRPC_ERROR_UNREF(error);
     return true;
   }
@@ -1755,7 +1765,6 @@ void XdsClient::ChannelState::LrsCallState::OnStatusReceivedLocked(
   }
   // Ignore status from a stale call.
   if (IsCurrentCallOnChannel()) {
-    GPR_ASSERT(!xds_client()->shutting_down_);
     // Try to restart the call.
     parent_->OnCallFinishedLocked();
   }
@@ -1899,8 +1908,6 @@ void XdsClient::WatchResource(const XdsResourceType* type,
   {
     MutexLock lock(&mu_);
     MaybeRegisterResourceTypeLocked(type);
-    // TODO(donnadionne): If we get a request for an authority that is not
-    // configured in the bootstrap file, reject it.
     AuthorityState& authority_state =
         authority_state_map_[resource_name->authority];
     ResourceState& resource_state =
@@ -2036,20 +2043,26 @@ std::string XdsClient::ConstructFullXdsResourceName(
 }
 
 RefCountedPtr<XdsClusterDropStats> XdsClient::AddClusterDropStats(
-    absl::string_view lrs_server, absl::string_view cluster_name,
+    const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
     absl::string_view eds_service_name) {
-  // TODO(roth): When we add support for direct federation, use the
+  if (!bootstrap_->XdsServerExists(xds_server)) return nullptr;
-  // server name specified in lrs_server.
   auto key =
       std::make_pair(std::string(cluster_name), std::string(eds_service_name));
   MutexLock lock(&mu_);
-  // We jump through some hoops here to make sure that the absl::string_views
+  // We jump through some hoops here to make sure that the const
-  // stored in the XdsClusterDropStats object point to the strings
+  // XdsBootstrap::XdsServer& and absl::string_views
+  // stored in the XdsClusterDropStats object point to the
+  // XdsBootstrap::XdsServer and strings
   // in the load_report_map_ key, so that they have the same lifetime.
-  auto it = load_report_map_
+  auto server_it =
-                .emplace(std::make_pair(std::move(key), LoadReportState()))
+      xds_load_report_server_map_.emplace(xds_server, LoadReportServer()).first;
+  if (server_it->second.channel_state == nullptr) {
+    server_it->second.channel_state = GetOrCreateChannelStateLocked(xds_server);
+  }
+  auto load_report_it = server_it->second.load_report_map
+                            .emplace(std::move(key), LoadReportState())
                             .first;
-  LoadReportState& load_report_state = it->second;
+  LoadReportState& load_report_state = load_report_it->second;
   RefCountedPtr<XdsClusterDropStats> cluster_drop_stats;
   if (load_report_state.drop_stats != nullptr) {
     cluster_drop_stats = load_report_state.drop_stats->RefIfNonZero();
@@ -2060,32 +2073,26 @@ RefCountedPtr<XdsClusterDropStats> XdsClient::AddClusterDropStats(
           load_report_state.drop_stats->GetSnapshotAndReset();
     }
     cluster_drop_stats = MakeRefCounted<XdsClusterDropStats>(
-        Ref(DEBUG_LOCATION, "DropStats"), lrs_server,
+        Ref(DEBUG_LOCATION, "DropStats"), server_it->first,
-        it->first.first /*cluster_name*/,
+        load_report_it->first.first /*cluster_name*/,
-        it->first.second /*eds_service_name*/);
+        load_report_it->first.second /*eds_service_name*/);
     load_report_state.drop_stats = cluster_drop_stats.get();
   }
-  auto resource_name =
+  server_it->second.channel_state->MaybeStartLrsCall();
-      ParseXdsResourceName(cluster_name, XdsClusterResourceType::Get());
-  GPR_ASSERT(resource_name.ok());
-  auto a = authority_state_map_.find(resource_name->authority);
-  if (a != authority_state_map_.end()) {
-    a->second.channel_state->MaybeStartLrsCall();
-  }
   return cluster_drop_stats;
 }
 
 void XdsClient::RemoveClusterDropStats(
-    absl::string_view /*lrs_server*/, absl::string_view cluster_name,
+    const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
     absl::string_view eds_service_name,
     XdsClusterDropStats* cluster_drop_stats) {
   MutexLock lock(&mu_);
-  // TODO(roth): When we add support for direct federation, use the
+  auto server_it = xds_load_report_server_map_.find(xds_server);
-  // server name specified in lrs_server.
+  if (server_it == xds_load_report_server_map_.end()) return;
-  auto it = load_report_map_.find(
+  auto load_report_it = server_it->second.load_report_map.find(
       std::make_pair(std::string(cluster_name), std::string(eds_service_name)));
-  if (it == load_report_map_.end()) return;
+  if (load_report_it == server_it->second.load_report_map.end()) return;
-  LoadReportState& load_report_state = it->second;
+  LoadReportState& load_report_state = load_report_it->second;
   if (load_report_state.drop_stats == cluster_drop_stats) {
     // Record final snapshot in deleted_drop_stats, which will be
     // added to the next load report.
@@ -2096,21 +2103,27 @@ void XdsClient::RemoveClusterDropStats(
 }
 
 RefCountedPtr<XdsClusterLocalityStats> XdsClient::AddClusterLocalityStats(
-    absl::string_view lrs_server, absl::string_view cluster_name,
+    const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
     absl::string_view eds_service_name,
     RefCountedPtr<XdsLocalityName> locality) {
-  // TODO(roth): When we add support for direct federation, use the
+  if (!bootstrap_->XdsServerExists(xds_server)) return nullptr;
-  // server name specified in lrs_server.
   auto key =
       std::make_pair(std::string(cluster_name), std::string(eds_service_name));
   MutexLock lock(&mu_);
-  // We jump through some hoops here to make sure that the absl::string_views
+  // We jump through some hoops here to make sure that the const
-  // stored in the XdsClusterLocalityStats object point to the strings
+  // XdsBootstrap::XdsServer& and absl::string_views
+  // stored in the XdsClusterDropStats object point to the
+  // XdsBootstrap::XdsServer and strings
   // in the load_report_map_ key, so that they have the same lifetime.
-  auto it = load_report_map_
+  auto server_it =
-                .emplace(std::make_pair(std::move(key), LoadReportState()))
+      xds_load_report_server_map_.emplace(xds_server, LoadReportServer()).first;
+  if (server_it->second.channel_state == nullptr) {
+    server_it->second.channel_state = GetOrCreateChannelStateLocked(xds_server);
+  }
+  auto load_report_it = server_it->second.load_report_map
+                            .emplace(std::move(key), LoadReportState())
                             .first;
-  LoadReportState& load_report_state = it->second;
+  LoadReportState& load_report_state = load_report_it->second;
   LoadReportState::LocalityState& locality_state =
       load_report_state.locality_stats[locality];
   RefCountedPtr<XdsClusterLocalityStats> cluster_locality_stats;
@@ -2123,33 +2136,27 @@ RefCountedPtr<XdsClusterLocalityStats> XdsClient::AddClusterLocalityStats(
           locality_state.locality_stats->GetSnapshotAndReset();
     }
     cluster_locality_stats = MakeRefCounted<XdsClusterLocalityStats>(
-        Ref(DEBUG_LOCATION, "LocalityStats"), lrs_server,
+        Ref(DEBUG_LOCATION, "LocalityStats"), server_it->first,
-        it->first.first /*cluster_name*/, it->first.second /*eds_service_name*/,
+        load_report_it->first.first /*cluster_name*/,
-        std::move(locality));
+        load_report_it->first.second /*eds_service_name*/, std::move(locality));
     locality_state.locality_stats = cluster_locality_stats.get();
   }
-  auto resource_name =
+  server_it->second.channel_state->MaybeStartLrsCall();
-      ParseXdsResourceName(cluster_name, XdsClusterResourceType::Get());
-  GPR_ASSERT(resource_name.ok());
-  auto a = authority_state_map_.find(resource_name->authority);
-  if (a != authority_state_map_.end()) {
-    a->second.channel_state->MaybeStartLrsCall();
-  }
   return cluster_locality_stats;
 }
 
 void XdsClient::RemoveClusterLocalityStats(
-    absl::string_view /*lrs_server*/, absl::string_view cluster_name,
+    const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
     absl::string_view eds_service_name,
     const RefCountedPtr<XdsLocalityName>& locality,
     XdsClusterLocalityStats* cluster_locality_stats) {
   MutexLock lock(&mu_);
-  // TODO(roth): When we add support for direct federation, use the
+  auto server_it = xds_load_report_server_map_.find(xds_server);
-  // server name specified in lrs_server.
+  if (server_it == xds_load_report_server_map_.end()) return;
-  auto it = load_report_map_.find(
+  auto load_report_it = server_it->second.load_report_map.find(
       std::make_pair(std::string(cluster_name), std::string(eds_service_name)));
-  if (it == load_report_map_.end()) return;
+  if (load_report_it == server_it->second.load_report_map.end()) return;
-  LoadReportState& load_report_state = it->second;
+  LoadReportState& load_report_state = load_report_it->second;
   auto locality_it = load_report_state.locality_stats.find(locality);
   if (locality_it == load_report_state.locality_stats.end()) return;
   LoadReportState::LocalityState& locality_state = locality_it->second;
@@ -2193,13 +2200,17 @@ void XdsClient::NotifyOnErrorLocked(grpc_error_handle error) {
 }
 
 XdsApi::ClusterLoadReportMap XdsClient::BuildLoadReportSnapshotLocked(
-    bool send_all_clusters, const std::set<std::string>& clusters) {
+    const XdsBootstrap::XdsServer& xds_server, bool send_all_clusters,
+    const std::set<std::string>& clusters) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO, "[xds_client %p] start building load report", this);
   }
   XdsApi::ClusterLoadReportMap snapshot_map;
-  for (auto load_report_it = load_report_map_.begin();
+  auto server_it = xds_load_report_server_map_.find(xds_server);
-       load_report_it != load_report_map_.end();) {
+  if (server_it == xds_load_report_server_map_.end()) return snapshot_map;
+  auto& load_report_map = server_it->second.load_report_map;
+  for (auto load_report_it = load_report_map.begin();
+       load_report_it != load_report_map.end();) {
     // Cluster key is cluster and EDS service name.
     const auto& cluster_key = load_report_it->first;
     LoadReportState& load_report = load_report_it->second;
@@ -2265,7 +2276,7 @@ XdsApi::ClusterLoadReportMap XdsClient::BuildLoadReportSnapshotLocked(
     // deleted stats objects, remove the entry.
     if (load_report.locality_stats.empty() &&
         load_report.drop_stats == nullptr) {
-      load_report_it = load_report_map_.erase(load_report_it);
+      load_report_it = load_report_map.erase(load_report_it);
     } else {
       ++load_report_it;
     }

src/core/ext/xds/xds_client.h

@@ -114,9 +114,9 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
   // Adds and removes drop stats for cluster_name and eds_service_name.
   RefCountedPtr<XdsClusterDropStats> AddClusterDropStats(
-      absl::string_view lrs_server, absl::string_view cluster_name,
+      const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
       absl::string_view eds_service_name);
-  void RemoveClusterDropStats(absl::string_view /*lrs_server*/,
+  void RemoveClusterDropStats(const XdsBootstrap::XdsServer& xds_server,
                               absl::string_view cluster_name,
                               absl::string_view eds_service_name,
                               XdsClusterDropStats* cluster_drop_stats);
@@ -124,11 +124,11 @@ class XdsClient : public DualRefCounted<XdsClient> {
   // Adds and removes locality stats for cluster_name and eds_service_name
   // for the specified locality.
   RefCountedPtr<XdsClusterLocalityStats> AddClusterLocalityStats(
-      absl::string_view lrs_server, absl::string_view cluster_name,
+      const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
       absl::string_view eds_service_name,
       RefCountedPtr<XdsLocalityName> locality);
   void RemoveClusterLocalityStats(
-      absl::string_view /*lrs_server*/, absl::string_view cluster_name,
+      const XdsBootstrap::XdsServer& xds_server, absl::string_view cluster_name,
       absl::string_view eds_service_name,
       const RefCountedPtr<XdsLocalityName>& locality,
       XdsClusterLocalityStats* cluster_locality_stats);
@@ -189,7 +189,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
     LrsCallState* lrs_calld() const;
 
     void MaybeStartLrsCall();
-    void StopLrsCall();
+    void StopLrsCallLocked() ABSL_EXCLUSIVE_LOCKS_REQUIRED(&XdsClient::mu_);
 
     bool HasAdsCall() const;
     bool HasActiveAdsCall() const;
@@ -255,6 +255,16 @@ class XdsClient : public DualRefCounted<XdsClient> {
     grpc_millis last_report_time = ExecCtx::Get()->Now();
   };
 
+  // Load report data.
+  using LoadReportMap = std::map<
+      std::pair<std::string /*cluster_name*/, std::string /*eds_service_name*/>,
+      LoadReportState>;
+
+  struct LoadReportServer {
+    RefCountedPtr<ChannelState> channel_state;
+    LoadReportMap load_report_map;
+  };
+
   class Notifier;
 
   // Sends an error notification to all watchers.
@@ -275,8 +285,8 @@ class XdsClient : public DualRefCounted<XdsClient> {
       const XdsResourceKey& key);
 
   XdsApi::ClusterLoadReportMap BuildLoadReportSnapshotLocked(
-      bool send_all_clusters, const std::set<std::string>& clusters)
+      const XdsBootstrap::XdsServer& xds_server, bool send_all_clusters,
-      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+      const std::set<std::string>& clusters) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
 
   RefCountedPtr<ChannelState> GetOrCreateChannelStateLocked(
       const XdsBootstrap::XdsServer& server) ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
@@ -305,11 +315,8 @@ class XdsClient : public DualRefCounted<XdsClient> {
   std::map<std::string /*authority*/, AuthorityState> authority_state_map_
       ABSL_GUARDED_BY(mu_);
 
-  // Load report data.
+  std::map<XdsBootstrap::XdsServer, LoadReportServer>
-  std::map<
+      xds_load_report_server_map_ ABSL_GUARDED_BY(mu_);
-      std::pair<std::string /*cluster_name*/, std::string /*eds_service_name*/>,
-      LoadReportState>
-      load_report_map_ ABSL_GUARDED_BY(mu_);
 
   // Stores started watchers whose resource name was not parsed successfully,
   // waiting to be cancelled or reset in Orphan().

src/core/ext/xds/xds_client_stats.cc

@@ -41,20 +41,20 @@ uint64_t GetAndResetCounter(std::atomic<uint64_t>* from) {
 // XdsClusterDropStats
 //
 
-XdsClusterDropStats::XdsClusterDropStats(RefCountedPtr<XdsClient> xds_client,
+XdsClusterDropStats::XdsClusterDropStats(
-                                         absl::string_view lrs_server_name,
+    RefCountedPtr<XdsClient> xds_client,
-                                         absl::string_view cluster_name,
+    const XdsBootstrap::XdsServer& lrs_server, absl::string_view cluster_name,
     absl::string_view eds_service_name)
     : RefCounted(GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace)
                      ? "XdsClusterDropStats"
                      : nullptr),
       xds_client_(std::move(xds_client)),
-      lrs_server_name_(lrs_server_name),
+      lrs_server_(lrs_server),
       cluster_name_(cluster_name),
       eds_service_name_(eds_service_name) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO, "[xds_client %p] created drop stats %p for {%s, %s, %s}",
-            xds_client_.get(), this, std::string(lrs_server_name_).c_str(),
+            xds_client_.get(), this, lrs_server_.server_uri.c_str(),
             std::string(cluster_name_).c_str(),
             std::string(eds_service_name_).c_str());
   }
@@ -64,11 +64,11 @@ XdsClusterDropStats::~XdsClusterDropStats() {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] destroying drop stats %p for {%s, %s, %s}",
-            xds_client_.get(), this, std::string(lrs_server_name_).c_str(),
+            xds_client_.get(), this, lrs_server_.server_uri.c_str(),
             std::string(cluster_name_).c_str(),
             std::string(eds_service_name_).c_str());
   }
-  xds_client_->RemoveClusterDropStats(lrs_server_name_, cluster_name_,
+  xds_client_->RemoveClusterDropStats(lrs_server_, cluster_name_,
                                       eds_service_name_, this);
   xds_client_.reset(DEBUG_LOCATION, "DropStats");
 }
@@ -95,21 +95,21 @@ void XdsClusterDropStats::AddCallDropped(const std::string& category) {
 //
 
 XdsClusterLocalityStats::XdsClusterLocalityStats(
-    RefCountedPtr<XdsClient> xds_client, absl::string_view lrs_server_name,
+    RefCountedPtr<XdsClient> xds_client,
-    absl::string_view cluster_name, absl::string_view eds_service_name,
+    const XdsBootstrap::XdsServer& lrs_server, absl::string_view cluster_name,
-    RefCountedPtr<XdsLocalityName> name)
+    absl::string_view eds_service_name, RefCountedPtr<XdsLocalityName> name)
     : RefCounted(GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_refcount_trace)
                      ? "XdsClusterLocalityStats"
                      : nullptr),
       xds_client_(std::move(xds_client)),
-      lrs_server_name_(lrs_server_name),
+      lrs_server_(lrs_server),
       cluster_name_(cluster_name),
       eds_service_name_(eds_service_name),
       name_(std::move(name)) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] created locality stats %p for {%s, %s, %s, %s}",
-            xds_client_.get(), this, std::string(lrs_server_name_).c_str(),
+            xds_client_.get(), this, lrs_server_.server_uri.c_str(),
             std::string(cluster_name_).c_str(),
             std::string(eds_service_name_).c_str(),
             name_->AsHumanReadableString().c_str());
@@ -120,12 +120,12 @@ XdsClusterLocalityStats::~XdsClusterLocalityStats() {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_xds_client_trace)) {
     gpr_log(GPR_INFO,
             "[xds_client %p] destroying locality stats %p for {%s, %s, %s, %s}",
-            xds_client_.get(), this, std::string(lrs_server_name_).c_str(),
+            xds_client_.get(), this, lrs_server_.server_uri.c_str(),
             std::string(cluster_name_).c_str(),
             std::string(eds_service_name_).c_str(),
             name_->AsHumanReadableString().c_str());
   }
-  xds_client_->RemoveClusterLocalityStats(lrs_server_name_, cluster_name_,
+  xds_client_->RemoveClusterLocalityStats(lrs_server_, cluster_name_,
                                           eds_service_name_, name_, this);
   xds_client_.reset(DEBUG_LOCATION, "LocalityStats");
 }

src/core/ext/xds/xds_client_stats.h

@@ -29,6 +29,7 @@
 #include "absl/strings/str_format.h"
 #include "absl/strings/string_view.h"
 
+#include "src/core/ext/xds/xds_bootstrap.h"
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/gprpp/memory.h"
 #include "src/core/lib/gprpp/ref_counted.h"
@@ -128,7 +129,7 @@ class XdsClusterDropStats : public RefCounted<XdsClusterDropStats> {
   };
 
   XdsClusterDropStats(RefCountedPtr<XdsClient> xds_client,
-                      absl::string_view lrs_server_name,
+                      const XdsBootstrap::XdsServer& lrs_server,
                       absl::string_view cluster_name,
                       absl::string_view eds_service_name);
   ~XdsClusterDropStats() override;
@@ -141,7 +142,7 @@ class XdsClusterDropStats : public RefCounted<XdsClusterDropStats> {
 
  private:
   RefCountedPtr<XdsClient> xds_client_;
-  absl::string_view lrs_server_name_;
+  const XdsBootstrap::XdsServer& lrs_server_;
   absl::string_view cluster_name_;
   absl::string_view eds_service_name_;
   std::atomic<uint64_t> uncategorized_drops_{0};
@@ -202,7 +203,7 @@ class XdsClusterLocalityStats : public RefCounted<XdsClusterLocalityStats> {
   };
 
   XdsClusterLocalityStats(RefCountedPtr<XdsClient> xds_client,
-                          absl::string_view lrs_server_name,
+                          const XdsBootstrap::XdsServer& lrs_server_,
                           absl::string_view cluster_name,
                           absl::string_view eds_service_name,
                           RefCountedPtr<XdsLocalityName> name);
@@ -216,7 +217,7 @@ class XdsClusterLocalityStats : public RefCounted<XdsClusterLocalityStats> {
 
  private:
   RefCountedPtr<XdsClient> xds_client_;
-  absl::string_view lrs_server_name_;
+  const XdsBootstrap::XdsServer& lrs_server_;
   absl::string_view cluster_name_;
   absl::string_view eds_service_name_;
   RefCountedPtr<XdsLocalityName> name_;

src/core/ext/xds/xds_cluster.cc

@@ -70,9 +70,9 @@ std::string XdsClusterResource::ToString() const {
     contents.push_back(absl::StrFormat("common_tls_context=%s",
                                        common_tls_context.ToString()));
   }
-  if (lrs_load_reporting_server_name.has_value()) {
+  if (lrs_load_reporting_server.has_value()) {
     contents.push_back(absl::StrFormat("lrs_load_reporting_server_name=%s",
-                                       lrs_load_reporting_server_name.value()));
+                                       lrs_load_reporting_server->server_uri));
   }
   contents.push_back(absl::StrCat("lb_policy=", lb_policy));
   if (lb_policy == "RING_HASH") {
@@ -369,7 +369,7 @@ grpc_error_handle CdsResourceParse(
       errors.push_back(GRPC_ERROR_CREATE_FROM_STATIC_STRING(
           ": LRS ConfigSource is not self."));
     }
-    cds_update->lrs_load_reporting_server_name.emplace("");
+    cds_update->lrs_load_reporting_server.emplace(context.server);
   }
   // The Cluster resource encodes the circuit breaking parameters in a list of
   // Thresholds messages, where each message specifies the parameters for a

src/core/ext/xds/xds_cluster.h

@@ -52,9 +52,7 @@ struct XdsClusterResource {
 
   // The LRS server to use for load reporting.
   // If not set, load reporting will be disabled.
-  // If set to the empty string, will use the same server we obtained the CDS
+  absl::optional<XdsBootstrap::XdsServer> lrs_load_reporting_server;
-  // data from.
-  absl::optional<std::string> lrs_load_reporting_server_name;
 
   // The LB policy to use (e.g., "ROUND_ROBIN" or "RING_HASH").
   std::string lb_policy;
@@ -71,8 +69,7 @@ struct XdsClusterResource {
            dns_hostname == other.dns_hostname &&
            prioritized_cluster_names == other.prioritized_cluster_names &&
            common_tls_context == other.common_tls_context &&
-           lrs_load_reporting_server_name ==
+           lrs_load_reporting_server == other.lrs_load_reporting_server &&
-               other.lrs_load_reporting_server_name &&
            lb_policy == other.lb_policy &&
            min_ring_size == other.min_ring_size &&
            max_ring_size == other.max_ring_size &&

test/core/xds/xds_bootstrap_test.cc

@@ -738,6 +738,32 @@ TEST(XdsBootstrapTest, CertificateProvidersFakePluginEmptyConfig) {
             0);
 }
 
+TEST(XdsBootstrapTest, XdsServerToJsonAndParse) {
+  gpr_setenv("GRPC_EXPERIMENTAL_XDS_FEDERATION", "true");
+  const char* json_str =
+      "    {"
+      "      \"server_uri\": \"fake:///lb\","
+      "      \"channel_creds\": ["
+      "        {"
+      "          \"type\": \"fake\","
+      "          \"ignore\": 0"
+      "        }"
+      "      ],"
+      "      \"ignore\": 0"
+      "    }";
+  grpc_error_handle error = GRPC_ERROR_NONE;
+  Json json = Json::Parse(json_str, &error);
+  ASSERT_EQ(error, GRPC_ERROR_NONE) << grpc_error_std_string(error);
+  XdsBootstrap::XdsServer xds_server =
+      XdsBootstrap::XdsServer::Parse(json, &error);
+  ASSERT_EQ(error, GRPC_ERROR_NONE) << grpc_error_std_string(error);
+  Json::Object output = xds_server.ToJson();
+  XdsBootstrap::XdsServer output_xds_server =
+      XdsBootstrap::XdsServer::Parse(output, &error);
+  ASSERT_EQ(error, GRPC_ERROR_NONE) << grpc_error_std_string(error);
+  gpr_unsetenv("GRPC_EXPERIMENTAL_XDS_FEDERATION");
+}
+
 }  // namespace
 }  // namespace testing
 }  // namespace grpc_core

test/cpp/end2end/xds/xds_end2end_test.cc

@@ -2580,7 +2580,7 @@ TEST_P(GlobalXdsClientTest, InvalidListenerStillExistsIfPreviouslyCached) {
 
 class XdsFederationTest : public XdsEnd2endTest {
  protected:
-  XdsFederationTest() : XdsEnd2endTest(2, 100, 0, true) {
+  XdsFederationTest() : XdsEnd2endTest(2, 3, 0, true) {
     authority_balancer_ = CreateAndStartBalancer();
   }
 
@@ -2876,6 +2876,121 @@ TEST_P(XdsFederationTest, FederationServer) {
   gpr_unsetenv("GRPC_EXPERIMENTAL_XDS_FEDERATION");
 }
 
+using XdsFederationLoadReportingTest = XdsFederationTest;
+
+// Channel is created with URI "xds://xds.example.com/server.example.com".
+// Bootstrap entry for that authority specifies a client listener name template.
+// Sending traffic to both default balancer and authority balancer and checking
+// load reporting with each one.
+TEST_P(XdsFederationLoadReportingTest, FederationMultipleLoadReportingTest) {
+  gpr_setenv("GRPC_EXPERIMENTAL_XDS_FEDERATION", "true");
+  const char* kAuthority = "xds.example.com";
+  const char* kNewServerName = "whee%/server.example.com";
+  const char* kNewListenerTemplate =
+      "xdstp://xds.example.com/envoy.config.listener.v3.Listener/"
+      "client/%s?psm_project_id=1234";
+  const char* kNewListenerName =
+      "xdstp://xds.example.com/envoy.config.listener.v3.Listener/"
+      "client/whee%25/server.example.com?psm_project_id=1234";
+  const char* kNewRouteConfigName =
+      "xdstp://xds.example.com/envoy.config.route.v3.RouteConfiguration/"
+      "new_route_config_name";
+  const char* kNewEdsServiceName =
+      "xdstp://xds.example.com/envoy.config.endpoint.v3.ClusterLoadAssignment/"
+      "edsservice_name";
+  const char* kNewClusterName =
+      "xdstp://xds.example.com/envoy.config.cluster.v3.Cluster/"
+      "cluster_name";
+  const size_t kNumRpcsToDefaultBalancer = 5;
+  const size_t kNumRpcsToAuthorityBalancer = 10;
+  BootstrapBuilder builder = BootstrapBuilder();
+  builder.AddAuthority(kAuthority,
+                       absl::StrCat("localhost:", authority_balancer_->port()),
+                       kNewListenerTemplate);
+  CreateClientsAndServers(builder);
+  StartAllBackends();
+  // Eds for 2 balancers to ensure RPCs sent using current stub go to backend 0
+  // and RPCs sent using the new stub go to backend 1.
+  EdsResourceArgs args({{"locality0", CreateEndpointsForBackends(0, 1)}});
+  balancer_->ads_service()->SetEdsResource(BuildEdsResource(args));
+  args = EdsResourceArgs({{"locality0", CreateEndpointsForBackends(1, 2)}});
+  authority_balancer_->ads_service()->SetEdsResource(
+      BuildEdsResource(args, kNewEdsServiceName));
+  authority_balancer_->lrs_service()->set_cluster_names({kNewClusterName});
+  // New cluster
+  Cluster new_cluster = default_cluster_;
+  new_cluster.set_name(kNewClusterName);
+  new_cluster.mutable_lrs_server()->mutable_self();
+  new_cluster.mutable_eds_cluster_config()->set_service_name(
+      kNewEdsServiceName);
+  authority_balancer_->ads_service()->SetCdsResource(new_cluster);
+  // New Route
+  RouteConfiguration new_route_config = default_route_config_;
+  new_route_config.set_name(kNewRouteConfigName);
+  new_route_config.mutable_virtual_hosts(0)
+      ->mutable_routes(0)
+      ->mutable_route()
+      ->set_cluster(kNewClusterName);
+  // New Listener
+  Listener listener = default_listener_;
+  listener.set_name(kNewListenerName);
+  SetListenerAndRouteConfiguration(authority_balancer_.get(), listener,
+                                   new_route_config);
+  // Ensure update has reached and send 10 RPCs to the current stub.
+  CheckRpcSendOk(kNumRpcsToDefaultBalancer);
+  // Create second channel to new target uri and send 1 RPC .
+  auto channel2 =
+      CreateChannel(/*failover_timeout=*/0, kNewServerName, kAuthority);
+  channel2->GetState(/*try_to_connect=*/true);
+  ASSERT_TRUE(
+      channel2->WaitForConnected(grpc_timeout_milliseconds_to_deadline(100)));
+  auto stub2 = grpc::testing::EchoTestService::NewStub(channel2);
+  for (size_t i = 0; i < kNumRpcsToAuthorityBalancer; ++i) {
+    ClientContext context;
+    EchoRequest request;
+    request.set_message(kRequestMessage);
+    EchoResponse response;
+    grpc::Status status = stub2->Echo(&context, request, &response);
+    EXPECT_TRUE(status.ok()) << "code=" << status.error_code()
+                             << " message=" << status.error_message();
+  }
+  // Each backend should have received the expected number of RPCs,
+  // and the load report also reflect the correct numbers.
+  EXPECT_EQ(kNumRpcsToAuthorityBalancer,
+            backends_[1]->backend_service()->request_count());
+  EXPECT_EQ(kNumRpcsToDefaultBalancer,
+            backends_[0]->backend_service()->request_count());
+  // Load report for authority LRS.
+  std::vector<ClientStats> authority_load_report =
+      authority_balancer_->lrs_service()->WaitForLoadReport();
+  ASSERT_EQ(authority_load_report.size(), 1UL);
+  ClientStats& authority_client_stats = authority_load_report.front();
+  EXPECT_EQ(kNumRpcsToAuthorityBalancer,
+            authority_client_stats.total_successful_requests());
+  EXPECT_EQ(0U, authority_client_stats.total_requests_in_progress());
+  EXPECT_EQ(kNumRpcsToAuthorityBalancer,
+            authority_client_stats.total_issued_requests());
+  EXPECT_EQ(0U, authority_client_stats.total_error_requests());
+  EXPECT_EQ(0U, authority_client_stats.total_dropped_requests());
+  EXPECT_EQ(1U, authority_balancer_->lrs_service()->request_count());
+  EXPECT_EQ(1U, authority_balancer_->lrs_service()->response_count());
+  // Load report for default LRS.
+  std::vector<ClientStats> default_load_report =
+      balancer_->lrs_service()->WaitForLoadReport();
+  ASSERT_EQ(default_load_report.size(), 1UL);
+  ClientStats& default_client_stats = default_load_report.front();
+  EXPECT_EQ(kNumRpcsToDefaultBalancer,
+            default_client_stats.total_successful_requests());
+  EXPECT_EQ(0U, default_client_stats.total_requests_in_progress());
+  EXPECT_EQ(kNumRpcsToDefaultBalancer,
+            default_client_stats.total_issued_requests());
+  EXPECT_EQ(0U, default_client_stats.total_error_requests());
+  EXPECT_EQ(0U, default_client_stats.total_dropped_requests());
+  EXPECT_EQ(1U, balancer_->lrs_service()->request_count());
+  EXPECT_EQ(1U, balancer_->lrs_service()->response_count());
+  gpr_unsetenv("GRPC_EXPERIMENTAL_XDS_FEDERATION");
+}
+
 class SecureNamingTest : public XdsEnd2endTest {
  public:
   SecureNamingTest()
@@ -13576,10 +13691,18 @@ INSTANTIATE_TEST_SUITE_P(
     ::testing::Values(
         TestType().set_bootstrap_source(TestType::kBootstrapFromEnvVar),
         TestType()
+            .set_bootstrap_source(TestType::kBootstrapFromEnvVar)
+            .set_enable_rds_testing()),
+    &TestTypeName);
+
+INSTANTIATE_TEST_SUITE_P(
+    XdsTest, XdsFederationLoadReportingTest,
+    ::testing::Values(TestType()
                           .set_bootstrap_source(TestType::kBootstrapFromEnvVar)
                           .set_enable_load_reporting(),
                       TestType()
                           .set_bootstrap_source(TestType::kBootstrapFromEnvVar)
+                          .set_enable_load_reporting()
                           .set_enable_rds_testing()),
     &TestTypeName);