SERVER-19554 merge ReplSetMetadata and ReplicationMetadata

11 files changed, 103 insertions, 106 deletions

diff --git a/src/mongo/s/catalog/dist_lock_catalog_impl.cpp b/src/mongo/s/catalog/dist_lock_catalog_impl.cpp
index fbfe5e0d34e..432b96494a5 100644
--- a/src/mongo/s/catalog/dist_lock_catalog_impl.cpp
+++ b/src/mongo/s/catalog/dist_lock_catalog_impl.cpp
@@ -41,7 +41,7 @@
 #include "mongo/db/query/find_and_modify_request.h"
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/rpc/get_status_from_command_result.h"
-#include "mongo/rpc/metadata.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/rpc/metadata/sharding_metadata.h"
 #include "mongo/s/catalog/type_lockpings.h"
 #include "mongo/s/catalog/type_locks.h"
@@ -59,7 +59,7 @@ namespace {
 const char kCmdResponseWriteConcernField[] = "writeConcernError";
 const char kFindAndModifyResponseResultDocField[] = "value";
 const char kLocalTimeField[] = "localTime";
-const BSONObj kReplMetadata = BSON(rpc::kReplicationMetadataFieldName << 1);
+const BSONObj kReplMetadata = BSON(rpc::kReplSetMetadataFieldName << 1);
 const ReadPreferenceSetting kReadPref(ReadPreference::PrimaryOnly, TagSet());
 
 /**
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
index b726d8d1689..6b14ca34876 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set.cpp
@@ -48,7 +48,7 @@
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/executor/network_interface.h"
 #include "mongo/rpc/get_status_from_command_result.h"
-#include "mongo/rpc/metadata.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/config_server_version.h"
 #include "mongo/s/catalog/dist_lock_manager.h"
 #include "mongo/s/catalog/type_actionlog.h"
@@ -92,7 +92,7 @@ namespace {
 const ReadPreferenceSetting kConfigReadSelector(ReadPreference::PrimaryOnly, TagSet{});
 const ReadPreferenceSetting kConfigPrimaryPreferredSelector(ReadPreference::PrimaryPreferred,
                                                             TagSet{});
-const BSONObj kReplMetadata(BSON(rpc::kReplicationMetadataFieldName << 1));
+const BSONObj kReplMetadata(BSON(rpc::kReplSetMetadataFieldName << 1));
 const int kInitialSSVRetries = 3;
 const int kActionLogCollectionSize = 1024 * 1024 * 2;
 const int kChangeLogCollectionSize = 1024 * 1024 * 10;
@@ -1125,6 +1125,7 @@ bool CatalogManagerReplicaSet::_runReadCommand(const std::string& dbname,
 
     auto resultStatus = _runCommandOnConfig(target.getValue(), dbname, cmdObj);
     if (!resultStatus.isOK()) {
+        log() << "DANNENPRINT: " << resultStatus.getStatus();
         return Command::appendCommandStatus(*result, resultStatus.getStatus());
     }
 
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_add_shard_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_add_shard_test.cpp
index bd7b874ee1b..bdd15bc299e 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_add_shard_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_add_shard_test.cpp
@@ -36,6 +36,7 @@
 #include "mongo/client/remote_command_targeter_factory_mock.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/query/lite_parsed_query.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
 #include "mongo/s/catalog/type_changelog.h"
@@ -122,7 +123,7 @@ protected:
             const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
             ASSERT_EQ(nss.ns(), DatabaseType::ConfigNS);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BatchedUpdateRequest actualBatchedUpdate;
             std::string errmsg;
@@ -214,7 +215,7 @@ TEST_F(AddShardTest, AddShardStandalone) {
     // in the previous call, in the config server metadata
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQ(request.target, configHost);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.toString(), DatabaseType::ConfigNS);
@@ -232,7 +233,7 @@ TEST_F(AddShardTest, AddShardStandalone) {
     onFindCommand([this](const RemoteCommandRequest& request) {
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.toString(), DatabaseType::ConfigNS);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
 
@@ -328,7 +329,7 @@ TEST_F(AddShardTest, AddShardStandaloneGenerateName) {
     // in the previous call, in the config server metadata
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQ(request.target, configHost);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.toString(), DatabaseType::ConfigNS);
@@ -344,7 +345,7 @@ TEST_F(AddShardTest, AddShardStandaloneGenerateName) {
     });
 
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.toString(), DatabaseType::ConfigNS);
@@ -365,7 +366,7 @@ TEST_F(AddShardTest, AddShardStandaloneGenerateName) {
 
     // New name is being generated for the new shard
     onFindCommand([this, &existingShard](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.toString(), ShardType::ConfigNS);
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_drop_coll_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_drop_coll_test.cpp
index d168b62edd0..e2af5b8393f 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_drop_coll_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_drop_coll_test.cpp
@@ -34,6 +34,7 @@
 #include "mongo/client/remote_command_targeter_mock.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/query/lite_parsed_query.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/dist_lock_manager_mock.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
@@ -100,11 +101,11 @@ public:
 
     void expectRemoveChunksAndMarkCollectionDropped() {
         onCommand([this](const RemoteCommandRequest& request) {
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
             ASSERT_EQ(_configHost, request.target);
             ASSERT_EQ("config", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BSONObj expectedCmd(fromjson(R"({
                 delete: "chunks",
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_log_action_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_log_action_test.cpp
index cbb0ded71d6..02e90693671 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_log_action_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_log_action_test.cpp
@@ -34,6 +34,7 @@
 #include "mongo/db/commands.h"
 #include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
 #include "mongo/s/catalog/type_actionlog.h"
@@ -61,7 +62,7 @@ public:
         onCommand([&response](const RemoteCommandRequest& request) {
             ASSERT_EQUALS("config", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BSONObj expectedCreateCmd = BSON("create" << ActionLogType::ConfigNS << "capped" << true
                                                       << "size" << 1024 * 1024 * 2);
@@ -75,7 +76,7 @@ public:
         onCommand([&expectedActionLog](const RemoteCommandRequest& request) {
             ASSERT_EQUALS("config", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BatchedInsertRequest actualBatchedInsert;
             std::string errmsg;
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_remove_shard_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_remove_shard_test.cpp
index 74245c53fa0..4794eabe0e4 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_remove_shard_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_remove_shard_test.cpp
@@ -37,6 +37,7 @@
 #include "mongo/db/commands.h"
 #include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
 #include "mongo/s/catalog/type_chunk.h"
@@ -146,7 +147,7 @@ TEST_F(RemoveShardTest, RemoveShardStartDraining) {
         ASSERT_EQUALS(configHost, request.target);
         ASSERT_EQUALS("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedUpdateRequest actualBatchedUpdate;
         std::string errmsg;
@@ -171,7 +172,7 @@ TEST_F(RemoveShardTest, RemoveShardStartDraining) {
     // Respond to request to reload information about existing shards
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
@@ -324,7 +325,7 @@ TEST_F(RemoveShardTest, RemoveShardCompletion) {
         ASSERT_EQUALS(configHost, request.target);
         ASSERT_EQUALS("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedDeleteRequest actualBatchedDelete;
         std::string errmsg;
@@ -347,7 +348,7 @@ TEST_F(RemoveShardTest, RemoveShardCompletion) {
     // Respond to request to reload information about existing shards
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_shard_collection_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_shard_collection_test.cpp
index 98d144fc961..64788d58b38 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_shard_collection_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_shard_collection_test.cpp
@@ -38,6 +38,7 @@
 #include "mongo/db/commands.h"
 #include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/task_executor.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/dist_lock_manager_mock.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
@@ -80,7 +81,7 @@ public:
     void expectGetDatabase(const DatabaseType& expectedDb) {
         onFindCommand([&](const RemoteCommandRequest& request) {
             ASSERT_EQUALS(configHost, request.target);
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
             ASSERT_EQ(DatabaseType::ConfigNS, nss.ns());
@@ -109,7 +110,7 @@ public:
             ASSERT_EQUALS(configHost, request.target);
             ASSERT_EQUALS("config", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BatchedUpdateRequest actualBatchedUpdate;
             std::string errmsg;
@@ -150,7 +151,7 @@ public:
     void expectReloadChunks(const std::string& ns, const vector<ChunkType>& chunks) {
         onFindCommand([&](const RemoteCommandRequest& request) {
             ASSERT_EQUALS(configHost, request.target);
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
             ASSERT_EQ(nss.ns(), ChunkType::ConfigNS);
@@ -183,7 +184,7 @@ public:
             ASSERT_EQUALS(configHost, request.target);
             ASSERT_EQUALS("config", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             BatchedUpdateRequest actualBatchedUpdate;
             std::string errmsg;
@@ -210,7 +211,7 @@ public:
     void expectReloadCollection(const CollectionType& collection) {
         onFindCommand([&](const RemoteCommandRequest& request) {
             ASSERT_EQUALS(configHost, request.target);
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
             ASSERT_EQ(nss.ns(), CollectionType::ConfigNS);
@@ -236,7 +237,7 @@ public:
     void expectLoadNewestChunk(const string& ns, const ChunkType& chunk) {
         onFindCommand([&](const RemoteCommandRequest& request) {
             ASSERT_EQUALS(configHost, request.target);
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
             ASSERT_EQ(nss.ns(), ChunkType::ConfigNS);
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test.cpp
index 9473bd7e26c..1dc3b907536 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test.cpp
@@ -87,7 +87,7 @@ TEST_F(CatalogManagerReplSetTest, GetCollectionExisting) {
     });
 
     onFindCommand([this, &expectedColl](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), CollectionType::ConfigNS);
@@ -140,7 +140,7 @@ TEST_F(CatalogManagerReplSetTest, GetDatabaseExisting) {
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), DatabaseType::ConfigNS);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
 
@@ -306,7 +306,7 @@ TEST_F(CatalogManagerReplSetTest, GetAllShardsValid) {
     });
 
     onFindCommand([this, &s1, &s2, &s3](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), ShardType::ConfigNS);
@@ -396,7 +396,7 @@ TEST_F(CatalogManagerReplSetTest, GetChunksForNSWithSortAndLimit) {
     });
 
     onFindCommand([this, &chunksQuery, chunkA, chunkB](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), ChunkType::ConfigNS);
@@ -438,7 +438,7 @@ TEST_F(CatalogManagerReplSetTest, GetChunksForNSNoSortNoLimit) {
     });
 
     onFindCommand([this, &chunksQuery](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), ChunkType::ConfigNS);
@@ -515,7 +515,7 @@ TEST_F(CatalogManagerReplSetTest, RunUserManagementReadCommand) {
     });
 
     onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQUALS("test", request.dbname);
         ASSERT_EQUALS(BSON("usersInfo" << 1), request.cmdObj);
@@ -596,7 +596,7 @@ TEST_F(CatalogManagerReplSetTest, RunUserManagementWriteCommandSuccess) {
                            << "test"),
                       request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BSONObjBuilder responseBuilder;
         Command::appendCommandStatus(responseBuilder,
@@ -696,7 +696,7 @@ TEST_F(CatalogManagerReplSetTest, RunUserManagementWriteCommandNotMasterRetrySuc
                            << "test"),
                       request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         return BSON("ok" << 1);
     });
@@ -718,7 +718,7 @@ TEST_F(CatalogManagerReplSetTest, GetGlobalSettingsBalancerDoc) {
     });
 
     onFindCommand([this, st1](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), SettingsType::ConfigNS);
@@ -750,7 +750,7 @@ TEST_F(CatalogManagerReplSetTest, GetGlobalSettingsChunkSizeDoc) {
     });
 
     onFindCommand([this, st1](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), SettingsType::ConfigNS);
@@ -779,7 +779,7 @@ TEST_F(CatalogManagerReplSetTest, GetGlobalSettingsInvalidDoc) {
     });
 
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), SettingsType::ConfigNS);
@@ -811,7 +811,7 @@ TEST_F(CatalogManagerReplSetTest, GetGlobalSettingsNonExistent) {
     });
 
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), SettingsType::ConfigNS);
@@ -866,7 +866,7 @@ TEST_F(CatalogManagerReplSetTest, GetCollectionsValidResultsNoDb) {
     });
 
     onFindCommand([this, coll1, coll2, coll3](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), CollectionType::ConfigNS);
@@ -917,7 +917,7 @@ TEST_F(CatalogManagerReplSetTest, GetCollectionsValidResultsWithDb) {
     });
 
     onFindCommand([this, coll1, coll2](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), CollectionType::ConfigNS);
@@ -967,7 +967,7 @@ TEST_F(CatalogManagerReplSetTest, GetCollectionsInvalidCollectionType) {
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), CollectionType::ConfigNS);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
 
@@ -1009,7 +1009,7 @@ TEST_F(CatalogManagerReplSetTest, GetDatabasesForShardValid) {
     });
 
     onFindCommand([this, dbt1, dbt2](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), DatabaseType::ConfigNS);
@@ -1081,7 +1081,7 @@ TEST_F(CatalogManagerReplSetTest, GetTagsForCollection) {
     });
 
     onFindCommand([this, tagA, tagB](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), TagsType::ConfigNS);
@@ -1165,7 +1165,7 @@ TEST_F(CatalogManagerReplSetTest, GetTagForChunkOneTagFound) {
         [this, chunk] { return assertGet(catalogManager()->getTagForChunk("test.coll", chunk)); });
 
     onFindCommand([this, chunk](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), TagsType::ConfigNS);
@@ -1209,7 +1209,7 @@ TEST_F(CatalogManagerReplSetTest, GetTagForChunkNoTagFound) {
         [this, chunk] { return assertGet(catalogManager()->getTagForChunk("test.coll", chunk)); });
 
     onFindCommand([this, chunk](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), TagsType::ConfigNS);
@@ -1250,7 +1250,7 @@ TEST_F(CatalogManagerReplSetTest, GetTagForChunkInvalidTagDoc) {
     });
 
     onFindCommand([this, chunk](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(nss.ns(), TagsType::ConfigNS);
@@ -1289,7 +1289,7 @@ TEST_F(CatalogManagerReplSetTest, UpdateDatabase) {
     onCommand([dbt](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedUpdateRequest actualBatchedUpdate;
         std::string errmsg;
@@ -1364,7 +1364,7 @@ TEST_F(CatalogManagerReplSetTest, ApplyChunkOpsDeprecated) {
     onCommand([updateOps, preCondition](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQUALS(updateOps, request.cmdObj["applyOps"].Obj());
         ASSERT_EQUALS(preCondition, request.cmdObj["preCondition"].Obj());
@@ -1398,7 +1398,7 @@ TEST_F(CatalogManagerReplSetTest, ApplyChunkOpsDeprecatedCommandFailed) {
         ASSERT_EQUALS(updateOps, request.cmdObj["applyOps"].Obj());
         ASSERT_EQUALS(preCondition, request.cmdObj["preCondition"].Obj());
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BSONObjBuilder responseBuilder;
         Command::appendCommandStatus(responseBuilder,
@@ -1432,7 +1432,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseSuccess) {
 
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
@@ -1476,7 +1476,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseSuccess) {
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         ASSERT_EQ(DatabaseType::ConfigNS, nss.ns());
         checkReadConcern(request.cmdObj, Timestamp(0, 0), 0);
         return vector<BSONObj>{};
@@ -1525,7 +1525,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseSuccess) {
         ASSERT_EQUALS(configHost, request.target);
         ASSERT_EQUALS("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedInsertRequest actualBatchedInsert;
         std::string errmsg;
@@ -1591,7 +1591,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseDBExists) {
     });
 
     onFindCommand([this, dbname](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
@@ -1630,7 +1630,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseDBExistsDifferentCase) {
     });
 
     onFindCommand([this, dbname, dbnameDiffCase](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
@@ -1669,7 +1669,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseNoShards) {
 
     // Report no databases with the same name already exist
     onFindCommand([this, dbname](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(DatabaseType::ConfigNS, nss.ns());
         checkReadConcern(request.cmdObj, Timestamp(0, 0), 0);
@@ -1678,7 +1678,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseNoShards) {
 
     // Report no shards exist
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
 
@@ -1717,7 +1717,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseDuplicateKeyOnInsert) {
 
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         auto query = assertGet(LiteParsedQuery::makeFromFindCommand(nss, request.cmdObj, false));
 
@@ -1759,7 +1759,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseDuplicateKeyOnInsert) {
     // Report no databases with the same name already exist
     onFindCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(configHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(DatabaseType::ConfigNS, nss.ns());
         checkReadConcern(request.cmdObj, Timestamp(0, 0), 0);
@@ -1811,7 +1811,7 @@ TEST_F(CatalogManagerReplSetTest, createDatabaseDuplicateKeyOnInsert) {
         ASSERT_EQUALS("config", request.dbname);
         ASSERT_FALSE(request.cmdObj.hasField(repl::ReadConcernArgs::kReadConcernFieldName));
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedInsertRequest actualBatchedInsert;
         std::string errmsg;
@@ -1870,7 +1870,7 @@ TEST_F(CatalogManagerReplSetTest, EnableShardingNoDBExists) {
 
     // Query to find if db already exists in config.
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         const NamespaceString nss(request.dbname, request.cmdObj.firstElement().String());
         ASSERT_EQ(DatabaseType::ConfigNS, nss.toString());
 
@@ -1909,7 +1909,7 @@ TEST_F(CatalogManagerReplSetTest, EnableShardingNoDBExists) {
         ASSERT_EQ(HostAndPort("config:123"), request.target);
         ASSERT_EQ("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BSONObj expectedCmd(fromjson(R"({
             update: "databases",
@@ -2006,7 +2006,7 @@ TEST_F(CatalogManagerReplSetTest, EnableShardingDBExists) {
         ASSERT_EQ(HostAndPort("config:123"), request.target);
         ASSERT_EQ("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BSONObj expectedCmd(fromjson(R"({
             update: "databases",
@@ -2101,16 +2101,14 @@ TEST_F(CatalogManagerReplSetTest, BasicReadAfterOpTime) {
         onCommandWithMetadata([this, &newOpTime, &lastOpTime](const RemoteCommandRequest& request) {
             ASSERT_EQUALS("test", request.dbname);
 
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
             ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
             checkReadConcern(request.cmdObj, lastOpTime.getTimestamp(), lastOpTime.getTerm());
 
-            ReplSetMetadata metadata(12, newOpTime, 100, 3);
+            ReplSetMetadata metadata(12, newOpTime, repl::OpTime(), 100, 3);
             BSONObjBuilder builder;
-            BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-            metadata.writeToMetadata(&replBuilder);
-            replBuilder.done();
+            metadata.writeToMetadata(&builder);
 
             return RemoteCommandResponse(BSON("ok" << 1), builder.obj(), Milliseconds(1));
         });
@@ -2137,16 +2135,14 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeShouldNotGoBack) {
     onCommandWithMetadata([this, &newOpTime, &highestOpTime](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("test", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
 
-        ReplSetMetadata metadata(12, newOpTime, 100, 3);
+        ReplSetMetadata metadata(12, newOpTime, repl::OpTime(), 100, 3);
         BSONObjBuilder builder;
-        BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-        metadata.writeToMetadata(&replBuilder);
-        replBuilder.done();
+        metadata.writeToMetadata(&builder);
 
         return RemoteCommandResponse(BSON("ok" << 1), builder.obj(), Milliseconds(1));
     });
@@ -2166,16 +2162,14 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeShouldNotGoBack) {
     onCommandWithMetadata([this, &oldOpTime, &highestOpTime](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("test", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
 
-        ReplSetMetadata metadata(12, oldOpTime, 100, 3);
+        ReplSetMetadata metadata(12, oldOpTime, repl::OpTime(), 100, 3);
         BSONObjBuilder builder;
-        BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-        metadata.writeToMetadata(&replBuilder);
-        replBuilder.done();
+        metadata.writeToMetadata(&builder);
 
         return RemoteCommandResponse(BSON("ok" << 1), builder.obj(), Milliseconds(1));
     });
@@ -2191,16 +2185,14 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeShouldNotGoBack) {
     onCommandWithMetadata([this, &oldOpTime, &highestOpTime](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("test", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
 
-        ReplSetMetadata metadata(12, oldOpTime, 100, 3);
+        ReplSetMetadata metadata(12, oldOpTime, repl::OpTime(), 100, 3);
         BSONObjBuilder builder;
-        BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-        metadata.writeToMetadata(&replBuilder);
-        replBuilder.done();
+        metadata.writeToMetadata(&builder);
 
         return RemoteCommandResponse(BSON("ok" << 1), builder.obj(), Milliseconds(1));
     });
@@ -2219,14 +2211,12 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeFindThenCmd) {
 
     onFindWithMetadataCommand(
         [this, &newOpTime, &highestOpTime](const RemoteCommandRequest& request) {
-            ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+            ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
             checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
 
-            ReplSetMetadata metadata(12, newOpTime, 100, 3);
+            ReplSetMetadata metadata(12, newOpTime, repl::OpTime(), 100, 3);
             BSONObjBuilder builder;
-            BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-            metadata.writeToMetadata(&replBuilder);
-            replBuilder.done();
+            metadata.writeToMetadata(&builder);
 
             SettingsType settings;
             settings.setKey("chunksize");
@@ -2250,7 +2240,7 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeFindThenCmd) {
     onCommand([this, &oldOpTime, &highestOpTime](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("test", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
@@ -2276,16 +2266,14 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeCmdThenFind) {
     onCommandWithMetadata([this, &newOpTime, &highestOpTime](const RemoteCommandRequest& request) {
         ASSERT_EQUALS("test", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("dummy"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
 
-        ReplSetMetadata metadata(12, newOpTime, 100, 3);
+        ReplSetMetadata metadata(12, newOpTime, repl::OpTime(), 100, 3);
         BSONObjBuilder builder;
-        BSONObjBuilder replBuilder(builder.subobjStart(rpc::kReplicationMetadataFieldName));
-        metadata.writeToMetadata(&replBuilder);
-        replBuilder.done();
+        metadata.writeToMetadata(&builder);
 
         return RemoteCommandResponse(BSON("ok" << 1), builder.obj(), Milliseconds(1));
     });
@@ -2301,7 +2289,7 @@ TEST_F(CatalogManagerReplSetTest, ReadAfterOpTimeCmdThenFind) {
     const repl::OpTime oldOpTime(Timestamp(3, 10), 5);
 
     onFindCommand([this, &oldOpTime, &highestOpTime](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(string("find"), request.cmdObj.firstElementFieldName());
         checkReadConcern(request.cmdObj, highestOpTime.getTimestamp(), highestOpTime.getTerm());
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
index 36eb4bbac64..477006aaa2a 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.cpp
@@ -44,6 +44,7 @@
 #include "mongo/db/service_context_noop.h"
 #include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/thread_pool_task_executor_test_fixture.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/dist_lock_manager_mock.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/type_changelog.h"
@@ -325,7 +326,7 @@ void CatalogManagerReplSetTestFixture::expectUpdateCollection(const HostAndPort&
                                                               const CollectionType& coll) {
     onCommand([&](const RemoteCommandRequest& request) {
         ASSERT_EQUALS(expectedHost, request.target);
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
         ASSERT_EQUALS("config", request.dbname);
 
         BatchedUpdateRequest actualBatchedUpdate;
diff --git a/src/mongo/s/catalog/replset/catalog_manager_replica_set_upgrade_test.cpp b/src/mongo/s/catalog/replset/catalog_manager_replica_set_upgrade_test.cpp
index 57d0694e5cb..f51c3010dd1 100644
--- a/src/mongo/s/catalog/replset/catalog_manager_replica_set_upgrade_test.cpp
+++ b/src/mongo/s/catalog/replset/catalog_manager_replica_set_upgrade_test.cpp
@@ -32,6 +32,7 @@
 
 #include "mongo/bson/json.h"
 #include "mongo/client/remote_command_targeter_mock.h"
+#include "mongo/rpc/metadata/repl_set_metadata.h"
 #include "mongo/s/catalog/config_server_version.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set.h"
 #include "mongo/s/catalog/replset/catalog_manager_replica_set_test_fixture.h"
@@ -54,7 +55,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNotNeeded) {
     auto future = launchAsync([this] { ASSERT_OK(catalogManager()->checkAndUpgrade(true)); });
 
     onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         ASSERT_EQ(HostAndPort("config:123"), request.target);
         ASSERT_EQ("config", request.dbname);
@@ -154,7 +155,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNoVersionDocEmptyConfig) {
         ASSERT_EQ("admin", request.dbname);
         ASSERT_EQ(BSON("listDatabases" << 1), request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         return fromjson(R"({
                     databases: [
@@ -169,7 +170,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNoVersionDocEmptyConfig) {
         ASSERT_EQ(HostAndPort("config:123"), request.target);
         ASSERT_EQ("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedUpdateRequest actualBatchedUpdate;
         std::string errmsg;
@@ -217,7 +218,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNoVersionDocEmptyConfigWithAdmin
         ASSERT_EQ("admin", request.dbname);
         ASSERT_EQ(BSON("listDatabases" << 1), request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         return fromjson(R"({
                     databases: [
@@ -233,7 +234,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNoVersionDocEmptyConfigWithAdmin
         ASSERT_EQ(HostAndPort("config:123"), request.target);
         ASSERT_EQ("config", request.dbname);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         BatchedUpdateRequest actualBatchedUpdate;
         std::string errmsg;
@@ -266,7 +267,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeWriteError) {
         ASSERT_EQ("admin", request.dbname);
         ASSERT_EQ(BSON("listDatabases" << 1), request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         return fromjson(R"({
                     databases: [
@@ -309,7 +310,7 @@ TEST_F(CatalogManagerReplSetTestFixture, UpgradeNoVersionDocNonEmptyConfigServer
         ASSERT_EQ("admin", request.dbname);
         ASSERT_EQ(BSON("listDatabases" << 1), request.cmdObj);
 
-        ASSERT_EQUALS(BSON(rpc::kReplicationMetadataFieldName << 1), request.metadata);
+        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
 
         return fromjson(R"({
                     databases: [
diff --git a/src/mongo/s/client/shard_registry.cpp b/src/mongo/s/client/shard_registry.cpp
index 921849312ce..321e6d86de3 100644
--- a/src/mongo/s/client/shard_registry.cpp
+++ b/src/mongo/s/client/shard_registry.cpp
@@ -292,8 +292,9 @@ StatusWith<ShardRegistry::QueryResponse> ShardRegistry::exhaustiveFind(
         }
 
         auto& data = dataStatus.getValue();
-        if (auto replField = data.otherFields.metadata[rpc::kReplicationMetadataFieldName]) {
-            auto replParseStatus = rpc::ReplSetMetadata::readFromMetadata(replField.Obj());
+        if (data.otherFields.metadata.hasField(rpc::kReplSetMetadataFieldName)) {
+            auto replParseStatus =
+                rpc::ReplSetMetadata::readFromMetadata(data.otherFields.metadata);
 
             if (!replParseStatus.isOK()) {
                 status = replParseStatus.getStatus();
@@ -301,7 +302,7 @@ StatusWith<ShardRegistry::QueryResponse> ShardRegistry::exhaustiveFind(
                 return;
             }
 
-            response.opTime = replParseStatus.getValue().getLastCommittedOptime();
+            response.opTime = replParseStatus.getValue().getLastOpCommitted();
         }
 
         for (const BSONObj& doc : data.documents) {
@@ -386,15 +387,15 @@ StatusWith<ShardRegistry::CommandResponse> ShardRegistry::runCommandWithMetadata
     CommandResponse cmdResponse;
     cmdResponse.response = response.data;
 
-    if (auto replField = response.metadata[rpc::kReplicationMetadataFieldName]) {
-        auto replParseStatus = rpc::ReplSetMetadata::readFromMetadata(replField.Obj());
+    if (response.metadata.hasField(rpc::kReplSetMetadataFieldName)) {
+        auto replParseStatus = rpc::ReplSetMetadata::readFromMetadata(response.metadata);
 
         if (!replParseStatus.isOK()) {
             return replParseStatus.getStatus();
         }
 
         // TODO: SERVER-19734 use config server snapshot time.
-        cmdResponse.opTime = replParseStatus.getValue().getLastCommittedOptime();
+        cmdResponse.opTime = replParseStatus.getValue().getLastOpCommitted();
     }
 
     return cmdResponse;