SERVER-59495 Donor and recipient tenant migration state machines will persist the migration protocol info and tenantId info will be an empty string for 'Merge' protcol.

Added a new optional "protocol" field to 'recipientSyncData' cmd & made 'tenantId' field as optional.

21 files changed, 355 insertions, 117 deletions

diff --git a/buildscripts/idl/idl/generator.py b/buildscripts/idl/idl/generator.py
index 51569af4d4f..c806d016296 100644
--- a/buildscripts/idl/idl/generator.py
+++ b/buildscripts/idl/idl/generator.py
@@ -230,24 +230,15 @@ class _FastFieldUsageChecker(_FieldUsageCheckerBase):
         with writer.IndentedScopedBlock(self._writer, 'if (MONGO_unlikely(!usedFields.all())) {',
                                         '}'):
             for field in self._fields:
-                if (not field.optional) and (not field.ignore):
+                # If 'field.default' is true, the fields(members) gets initialized with the default
+                # value in the class definition. So, it's ok to skip setting the field to
+                # default value here.
+                if (not field.optional) and (not field.ignore) and (not field.default):
                     with writer.IndentedScopedBlock(
                             self._writer,
                             'if (!usedFields[%s]) {' % (_gen_field_usage_constant(field)), '}'):
-                        if field.default:
-                            default_value = (field.type.cpp_type + "::" + field.default) \
-                                if field.type.is_enum else field.default
-                            if field.chained_struct_field:
-                                self._writer.write_line(
-                                    '%s.%s(%s);' %
-                                    (_get_field_member_name(field.chained_struct_field),
-                                     _get_field_member_setter_name(field), default_value))
-                            else:
-                                self._writer.write_line(
-                                    '%s = %s;' % (_get_field_member_name(field), default_value))
-                        else:
-                            self._writer.write_line(
-                                'ctxt.throwMissingField(%s);' % (_get_field_constant_name(field)))
+                        self._writer.write_line(
+                            'ctxt.throwMissingField(%s);' % (_get_field_constant_name(field)))
 
 
 class _SlowFieldUsageChecker(_FastFieldUsageChecker):
diff --git a/jstests/replsets/libs/tenant_migration_util.js b/jstests/replsets/libs/tenant_migration_util.js
index 9d89ceee585..6a07a83065c 100644
--- a/jstests/replsets/libs/tenant_migration_util.js
+++ b/jstests/replsets/libs/tenant_migration_util.js
@@ -37,7 +37,7 @@ var TenantMigrationUtil = (function() {
      */
     function donorStartMigrationWithProtocol(cmd, db) {
         // If we don't pass "protocol", the server uses "multitenant migrations" by default.
-        if (isShardMergeEnabled(db)) {
+        if (cmd['protocol'] === undefined && isShardMergeEnabled(db)) {
             return Object.assign(Object.assign({}, cmd), {protocol: "shard merge"});
         }
 
diff --git a/jstests/replsets/shard_merge_enabled.js b/jstests/replsets/shard_merge_enabled.js
index 8c02658fad0..66760137999 100644
--- a/jstests/replsets/shard_merge_enabled.js
+++ b/jstests/replsets/shard_merge_enabled.js
@@ -7,6 +7,7 @@
 "use strict";
 
 load("jstests/replsets/libs/tenant_migration_util.js");
+load("jstests/libs/fail_point_util.js");
 
 function runTest(downgradeFCV) {
     let rst = new ReplSetTest({nodes: 1});
@@ -16,37 +17,62 @@ function runTest(downgradeFCV) {
     let primary = rst.getPrimary();
     let adminDB = primary.getDB("admin");
     const kDummyConnStr = "mongodb://localhost/?replicaSet=foo";
+    const readPreference = {mode: 'primary'};
+    const migrationCertificates = TenantMigrationUtil.makeMigrationCertificatesForTest();
+
     // A function, not a constant, to ensure unique UUIDs.
     function donorStartMigrationCmd() {
         return {
             donorStartMigration: 1,
             protocol: "shard merge",
-            tenantId: "foo",
             migrationId: UUID(),
             recipientConnectionString: kDummyConnStr,
-            readPreference: {mode: "primary"},
+            readPreference: readPreference,
+            donorCertificateForRecipient: migrationCertificates.donorCertificateForRecipient,
+            recipientCertificateForDonor: migrationCertificates.recipientCertificateForDonor
+        };
+    }
+
+    function recipientSyncDataCmd() {
+        return {
+            recipientSyncData: 1,
+            protocol: "shard merge",
+            migrationId: UUID(),
+            donorConnectionString: kDummyConnStr,
+            readPreference: readPreference,
+            startMigrationDonorTimestamp: Timestamp(1, 1),
+            recipientCertificateForDonor: migrationCertificates.recipientCertificateForDonor
         };
     }
 
+    // Enable below fail points to prevent starting the donor/recipient POS instance.
+    configureFailPoint(primary, "returnResponseCommittedForDonorStartMigrationCmd");
+    configureFailPoint(primary, "returnResponseOkForRecipientSyncDataCmd");
+
     // Preconditions: the shard merge feature is enabled and our fresh RS is on the latest FCV.
     assert(TenantMigrationUtil.isShardMergeEnabled(adminDB));
     assert.eq(getFCVConstants().latest,
               adminDB.system.version.findOne({_id: 'featureCompatibilityVersion'}).version);
 
-    // Shard merge is enabled, so this call will fail for some *other* reason, e.g. no certificates,
-    // recipient is unavailable.
-    let res = adminDB.runCommand(donorStartMigrationCmd());
-    assert.neq(res.code,
-               5949300,
-               "donorStartMigration shouldn't reject 'shard merge' protocol when it's enabled");
+    // Shard merge is enabled, so this call should work.
+    assert.commandWorked(
+        adminDB.runCommand(donorStartMigrationCmd()),
+        "donorStartMigration shouldn't reject 'shard merge' protocol when it's enabled");
+    assert.commandWorked(
+        adminDB.runCommand(recipientSyncDataCmd()),
+        "recipientSyncDataCmd shouldn't reject 'shard merge' protocol when it's enabled");
 
     assert.commandWorked(adminDB.adminCommand({setFeatureCompatibilityVersion: downgradeFCV}));
 
     // Now that FCV is downgraded, shard merge is automatically disabled.
     assert.commandFailedWithCode(
         adminDB.runCommand(donorStartMigrationCmd()),
-        5949300,
+        ErrorCodes.IllegalOperation,
         "donorStartMigration should reject 'shard merge' protocol when it's disabled");
+    assert.commandFailedWithCode(
+        adminDB.runCommand(recipientSyncDataCmd()),
+        ErrorCodes.IllegalOperation,
+        "recipientSyncDataCmd should reject 'shard merge' protocol when it's disabled");
 
     rst.stopSet();
 }
diff --git a/jstests/replsets/tenant_migration_invalid_inputs.js b/jstests/replsets/tenant_migration_invalid_inputs.js
index a680a7164d8..3ac39c57fe0 100644
--- a/jstests/replsets/tenant_migration_invalid_inputs.js
+++ b/jstests/replsets/tenant_migration_invalid_inputs.js
@@ -9,6 +9,7 @@
  *   incompatible_with_macos,
  *   incompatible_with_windows_tls,
  *   requires_persistence,
+ *   requires_fcv_51,
  * ]
  */
 
@@ -32,6 +33,21 @@ const migrationCertificates = TenantMigrationUtil.makeMigrationCertificatesForTe
 
 jsTestLog("Testing 'donorStartMigration' command provided with invalid options.");
 
+// Test missing tenantId field for protocol 'multitenant migrations'.
+assert.commandFailedWithCode(
+    donorPrimary.adminCommand(
+        TenantMigrationUtil.donorStartMigrationWithProtocol({
+            donorStartMigration: 1,
+            protocol: 'multitenant migrations',
+            migrationId: UUID(),
+            recipientConnectionString: tenantMigrationTest.getRecipientRst().getURL(),
+            readPreference: readPreference,
+            donorCertificateForRecipient: migrationCertificates.donorCertificateForRecipient,
+            recipientCertificateForDonor: migrationCertificates.recipientCertificateForDonor,
+        },
+                                                            donorPrimary.getDB("admin"))),
+    ErrorCodes.InvalidOptions);
+
 // Test unsupported database prefixes.
 const unsupportedtenantIds = ['', 'admin', 'local', 'config'];
 unsupportedtenantIds.forEach((invalidTenantId) => {
@@ -98,6 +114,18 @@ assert.commandFailedWithCode(
 
 jsTestLog("Testing 'recipientSyncData' command provided with invalid options.");
 
+// Test missing tenantId field for protocol 'multitenant migrations'.
+assert.commandFailedWithCode(recipientPrimary.adminCommand({
+    recipientSyncData: 1,
+    protocol: 'multitenant migrations',
+    migrationId: UUID(),
+    donorConnectionString: tenantMigrationTest.getDonorRst().getURL(),
+    startMigrationDonorTimestamp: Timestamp(1, 1),
+    readPreference: readPreference,
+    recipientCertificateForDonor: migrationCertificates.recipientCertificateForDonor,
+}),
+                             ErrorCodes.InvalidOptions);
+
 // Test unsupported database prefixes.
 unsupportedtenantIds.forEach((invalidTenantId) => {
     assert.commandFailedWithCode(recipientPrimary.adminCommand({
diff --git a/src/mongo/db/commands/SConscript b/src/mongo/db/commands/SConscript
index a9281408827..92de98db68b 100644
--- a/src/mongo/db/commands/SConscript
+++ b/src/mongo/db/commands/SConscript
@@ -625,6 +625,7 @@ env.Library(
         '$BUILD_DIR/mongo/client/read_preference',
         '$BUILD_DIR/mongo/db/repl/repl_coordinator_interface',
         '$BUILD_DIR/mongo/db/repl/tenant_migration_state_machine_idl',
+        '$BUILD_DIR/mongo/db/serverless/serverless_types_idl',
         '$BUILD_DIR/mongo/idl/idl_parser',
     ]
 )
diff --git a/src/mongo/db/commands/tenant_migration_donor_cmds.cpp b/src/mongo/db/commands/tenant_migration_donor_cmds.cpp
index fb78d7099b1..f23c320391a 100644
--- a/src/mongo/db/commands/tenant_migration_donor_cmds.cpp
+++ b/src/mongo/db/commands/tenant_migration_donor_cmds.cpp
@@ -26,6 +26,7 @@
  *    exception statement from all source files in the program, then also delete
  *    it in the license file.
  */
+#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kCommand
 
 #include "mongo/db/auth/authorization_session.h"
 #include "mongo/db/commands.h"
@@ -36,10 +37,13 @@
 #include "mongo/db/repl/replication_coordinator.h"
 #include "mongo/db/repl/tenant_migration_access_blocker_util.h"
 #include "mongo/db/repl/tenant_migration_donor_service.h"
+#include "mongo/logv2/log.h"
 
 namespace mongo {
 namespace {
 
+MONGO_FAIL_POINT_DEFINE(returnResponseCommittedForDonorStartMigrationCmd);
+
 class DonorStartMigrationCmd : public TypedCommand<DonorStartMigrationCmd> {
 public:
     using Request = DonorStartMigration;
@@ -68,19 +72,14 @@ public:
 
             const auto& cmd = request();
 
-            if (cmd.getProtocol().value_or(MigrationProtocolEnum::kMultitenantMigrations) ==
-                MigrationProtocolEnum::kShardMerge) {
-                uassert(5949300,
-                        "protocol \"shard merge\" not supported",
-                        repl::feature_flags::gShardMerge.isEnabled(
-                            serverGlobalParams.featureCompatibility));
-            }
+            tenant_migration_util::protocolCompatibilityCheck(cmd.getProtocol(),
+                                                              cmd.getTenantId().toString());
 
-            // TODO (SERVER-59494): tenantId should be optional in the state doc. Include protocol.
             TenantMigrationDonorDocument stateDoc(cmd.getMigrationId(),
                                                   cmd.getRecipientConnectionString().toString(),
                                                   cmd.getReadPreference(),
-                                                  cmd.getTenantId().toString());
+                                                  cmd.getTenantId().toString(),
+                                                  cmd.getProtocol());
 
             if (!repl::tenantMigrationDisableX509Auth) {
                 uassert(ErrorCodes::InvalidOptions,
@@ -97,6 +96,14 @@ public:
 
             const auto stateDocBson = stateDoc.toBSON();
 
+            if (MONGO_unlikely(returnResponseCommittedForDonorStartMigrationCmd.shouldFail())) {
+                LOGV2(5949401,
+                      "Immediately returning committed because "
+                      "'returnResponseCommittedForDonorStartMigrationCmd' failpoint is enabled",
+                      "tenantMigrationDonorInstance"_attr = stateDoc.toBSON());
+                return Response(TenantMigrationDonorStateEnum::kCommitted);
+            }
+
             auto donorService =
                 repl::PrimaryOnlyServiceRegistry::get(opCtx->getServiceContext())
                     ->lookupServiceByName(TenantMigrationDonorService::kServiceName);
diff --git a/src/mongo/db/commands/tenant_migration_donor_cmds.idl b/src/mongo/db/commands/tenant_migration_donor_cmds.idl
index 750504590f9..3c08f095093 100644
--- a/src/mongo/db/commands/tenant_migration_donor_cmds.idl
+++ b/src/mongo/db/commands/tenant_migration_donor_cmds.idl
@@ -35,17 +35,10 @@ global:
 imports:
   - "mongo/client/read_preference_setting.idl"
   - "mongo/db/repl/tenant_migration_state_machine.idl"
+  - "mongo/db/serverless/serverless_types.idl"
   - "mongo/idl/basic_types.idl"
   - "mongo/s/sharding_types.idl"
 
-enums:
-    MigrationProtocol:
-        description: "Determines which tenant migration protocol to use."
-        type: string
-        values:
-            kMultitenantMigrations: "multitenant migrations"
-            kShardMerge: "shard merge"
-
 structs:
     DonorStartMigrationResponse:
         description: "Response of the donorStartMigration command"
@@ -78,6 +71,7 @@ commands:
       tenantId:
         description: "The prefix from which the migrating database will be matched. The prefixes 'admin', 'local', 'config', the empty string, are not allowed."
         type: string
+        default: '""'
         validator:
           callback: "tenant_migration_util::validateDatabasePrefix"
       readPreference:
@@ -98,9 +92,9 @@ commands:
         # TODO (SERVER-54085): Remove server parameter tenantMigrationDisableX509Auth.
         optional: true
       protocol:
-        description: "Which migration protocol to use, default 'multitenant migrations'."
+        description: "Which migration protocol to use."
         type: MigrationProtocol
-        optional: true
+        default: kMultitenantMigrations
 
   donorForgetMigration:
     description: "Parser for the 'donorForgetMigration' command."
diff --git a/src/mongo/db/commands/tenant_migration_recipient_cmds.cpp b/src/mongo/db/commands/tenant_migration_recipient_cmds.cpp
index b18f5b4c013..dc9f4d9889e 100644
--- a/src/mongo/db/commands/tenant_migration_recipient_cmds.cpp
+++ b/src/mongo/db/commands/tenant_migration_recipient_cmds.cpp
@@ -34,7 +34,6 @@
 #include "mongo/db/commands/tenant_migration_donor_cmds_gen.h"
 #include "mongo/db/commands/tenant_migration_recipient_cmds_gen.h"
 #include "mongo/db/repl/primary_only_service.h"
-#include "mongo/db/repl/repl_server_parameters_gen.h"
 #include "mongo/db/repl/tenant_migration_recipient_service.h"
 #include "mongo/logv2/log.h"
 
@@ -70,11 +69,16 @@ public:
 
             const auto& cmd = request();
 
+            tenant_migration_util::protocolCompatibilityCheck(cmd.getProtocol(),
+                                                              cmd.getTenantId().toString());
+
             TenantMigrationRecipientDocument stateDoc(cmd.getMigrationId(),
                                                       cmd.getDonorConnectionString().toString(),
                                                       cmd.getTenantId().toString(),
                                                       cmd.getStartMigrationDonorTimestamp(),
-                                                      cmd.getReadPreference());
+                                                      cmd.getReadPreference(),
+                                                      cmd.getProtocol());
+
 
             if (!repl::tenantMigrationDisableX509Auth) {
                 uassert(ErrorCodes::InvalidOptions,
@@ -88,7 +92,8 @@ public:
 
             if (MONGO_unlikely(returnResponseOkForRecipientSyncDataCmd.shouldFail())) {
                 LOGV2(4879608,
-                      "'returnResponseOkForRecipientSyncDataCmd' failpoint enabled.",
+                      "Immediately returning OK because 'returnResponseOkForRecipientSyncDataCmd' "
+                      "failpoint is enabled.",
                       "tenantMigrationRecipientInstance"_attr = stateDoc.toBSON());
                 return Response(repl::OpTime());
             }
@@ -180,6 +185,9 @@ public:
 
             const auto& cmd = request();
 
+            tenant_migration_util::protocolCompatibilityCheck(cmd.getProtocol(),
+                                                              cmd.getTenantId().toString());
+
             opCtx->setAlwaysInterruptAtStepDownOrUp();
             auto recipientService =
                 repl::PrimaryOnlyServiceRegistry::get(opCtx->getServiceContext())
@@ -195,7 +203,8 @@ public:
                                                       cmd.getDonorConnectionString().toString(),
                                                       cmd.getTenantId().toString(),
                                                       kUnusedStartMigrationTimestamp,
-                                                      cmd.getReadPreference());
+                                                      cmd.getReadPreference(),
+                                                      cmd.getProtocol());
             if (!repl::tenantMigrationDisableX509Auth) {
                 uassert(ErrorCodes::InvalidOptions,
                         str::stream() << "'" << Request::kRecipientCertificateForDonorFieldName
diff --git a/src/mongo/db/commands/tenant_migration_recipient_cmds.idl b/src/mongo/db/commands/tenant_migration_recipient_cmds.idl
index 6a4b44c9752..60ed03fa4de 100644
--- a/src/mongo/db/commands/tenant_migration_recipient_cmds.idl
+++ b/src/mongo/db/commands/tenant_migration_recipient_cmds.idl
@@ -36,6 +36,7 @@ global:
 imports:
   - "mongo/client/read_preference_setting.idl"
   - "mongo/db/repl/tenant_migration_pem_payload.idl"
+  - "mongo/db/serverless/serverless_types.idl"
   - "mongo/idl/basic_types.idl"
   - "mongo/s/sharding_types.idl"
   - "mongo/db/repl/replication_types.idl"
@@ -68,6 +69,7 @@ structs:
             The prefix from which the migrating database will be matched. The prefixes 'admin',
             'local', 'config', the empty string, are not allowed.
           type: string
+          default: '""'
           validator:
             callback: "tenant_migration_util::validateDatabasePrefix"
         readPreference:
@@ -81,6 +83,10 @@ structs:
           type: TenantMigrationPEMPayload
           # TODO (SERVER-54085): Remove server parameter tenantMigrationDisableX509Auth.
           optional: true
+        protocol:
+          description: "Which migration protocol to use."
+          type: MigrationProtocol
+          default: kMultitenantMigrations
 
 commands:
   recipientSyncData:
diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 2a35874c14b..adb0d690fc7 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -1277,6 +1277,7 @@ env.Library(
         '$BUILD_DIR/mongo/client/connection_string',
         '$BUILD_DIR/mongo/client/read_preference',
         '$BUILD_DIR/mongo/db/commands/mongod_fcv',
+        '$BUILD_DIR/mongo/db/serverless/serverless_types_idl',
         '$BUILD_DIR/mongo/idl/idl_parser',
         '$BUILD_DIR/mongo/util/net/ssl_manager',
         'optime',
diff --git a/src/mongo/db/repl/tenant_migration_donor_service.cpp b/src/mongo/db/repl/tenant_migration_donor_service.cpp
index b029481101f..6b93c558456 100644
--- a/src/mongo/db/repl/tenant_migration_donor_service.cpp
+++ b/src/mongo/db/repl/tenant_migration_donor_service.cpp
@@ -235,10 +235,11 @@ TenantMigrationDonorService::Instance::Instance(ServiceContext* const serviceCon
       _serviceContext(serviceContext),
       _donorService(donorService),
       _stateDoc(tenant_migration_access_blocker::parseDonorStateDocument(initialState)),
-      _instanceName(kServiceName + "-" + _stateDoc.getTenantId()),
+      _instanceName(kServiceName + "-" + _stateDoc.getId().toString()),
       _recipientUri(
           uassertStatusOK(MongoURI::parse(_stateDoc.getRecipientConnectionString().toString()))),
       _tenantId(_stateDoc.getTenantId()),
+      _protocol(_stateDoc.getProtocol()),
       _recipientConnectionString(_stateDoc.getRecipientConnectionString()),
       _readPreference(_stateDoc.getReadPreference()),
       _migrationUuid(_stateDoc.getId()),
@@ -246,6 +247,7 @@ TenantMigrationDonorService::Instance::Instance(ServiceContext* const serviceCon
       _recipientCertificateForDonor(_stateDoc.getRecipientCertificateForDonor()),
       _sslMode(repl::tenantMigrationDisableX509Auth ? transport::kGlobalSSLMode
                                                     : transport::kEnableSSL) {
+
     _recipientCmdExecutor = _makeRecipientCmdExecutor();
     _recipientCmdExecutor->startup();
 
@@ -384,7 +386,7 @@ Status TenantMigrationDonorService::Instance::checkIfOptionsConflict(
     stdx::lock_guard<Latch> lg(_mutex);
     invariant(stateDoc.getId() == _migrationUuid);
 
-    if (stateDoc.getTenantId() == _tenantId &&
+    if (stateDoc.getProtocol() == _protocol && stateDoc.getTenantId() == _tenantId &&
         stateDoc.getRecipientConnectionString() == _recipientConnectionString &&
         stateDoc.getReadPreference().equals(_readPreference) &&
         stateDoc.getDonorCertificateForRecipient() == _donorCertificateForRecipient &&
@@ -716,8 +718,11 @@ ExecutorFuture<void> TenantMigrationDonorService::Instance::_sendRecipientSyncDa
         request.setDbName(NamespaceString::kAdminDb);
 
         MigrationRecipientCommonData commonData(
-            _migrationUuid, donorConnString.toString(), _tenantId, _readPreference);
+            _migrationUuid, donorConnString.toString(), _readPreference);
         commonData.setRecipientCertificateForDonor(_recipientCertificateForDonor);
+        commonData.setProtocol(_protocol);
+        // TODO: Pass tenantId only for 'kMultitenantMigrations' protocol.
+        commonData.setTenantId(_tenantId);
         request.setMigrationRecipientCommonData(commonData);
 
         stdx::lock_guard<Latch> lg(_mutex);
@@ -743,8 +748,11 @@ ExecutorFuture<void> TenantMigrationDonorService::Instance::_sendRecipientForget
     request.setDbName(NamespaceString::kAdminDb);
 
     MigrationRecipientCommonData commonData(
-        _migrationUuid, donorConnString.toString(), _tenantId, _readPreference);
+        _migrationUuid, donorConnString.toString(), _readPreference);
     commonData.setRecipientCertificateForDonor(_recipientCertificateForDonor);
+    commonData.setProtocol(_protocol);
+    // TODO: Pass tenantId only for 'kMultitenantMigrations' protocol.
+    commonData.setTenantId(_tenantId);
     request.setMigrationRecipientCommonData(commonData);
 
     return _sendCommandToRecipient(executor, recipientTargeterRS, request.toBSON(BSONObj()), token);
diff --git a/src/mongo/db/repl/tenant_migration_donor_service.h b/src/mongo/db/repl/tenant_migration_donor_service.h
index 5322703b201..5a167edeb81 100644
--- a/src/mongo/db/repl/tenant_migration_donor_service.h
+++ b/src/mongo/db/repl/tenant_migration_donor_service.h
@@ -33,7 +33,6 @@
 #include "mongo/client/fetcher.h"
 #include "mongo/client/remote_command_targeter_rs.h"
 #include "mongo/db/repl/primary_only_service.h"
-#include "mongo/db/repl/repl_server_parameters_gen.h"
 #include "mongo/db/repl/tenant_migration_access_blocker_util.h"
 #include "mongo/executor/thread_pool_task_executor.h"
 #include "mongo/util/cancellation.h"
@@ -139,6 +138,10 @@ public:
             return _stateDoc.getTenantId();
         }
 
+        MigrationProtocolEnum getProtocol() const {
+            return _stateDoc.getProtocol();
+        }
+
         StringData getRecipientConnectionString() const {
             return _stateDoc.getRecipientConnectionString();
         }
@@ -330,6 +333,7 @@ public:
         // This data is provided in the initial state doc and never changes.  We keep copies to
         // avoid having to obtain the mutex to access them.
         const std::string _tenantId;
+        const MigrationProtocolEnum _protocol;
         const std::string _recipientConnectionString;
         const ReadPreferenceSetting _readPreference;
         const UUID _migrationUuid;
diff --git a/src/mongo/db/repl/tenant_migration_donor_service_test.cpp b/src/mongo/db/repl/tenant_migration_donor_service_test.cpp
index 53588c3c158..94c244e40d9 100644
--- a/src/mongo/db/repl/tenant_migration_donor_service_test.cpp
+++ b/src/mongo/db/repl/tenant_migration_donor_service_test.cpp
@@ -186,7 +186,8 @@ TEST_F(TenantMigrationDonorServiceTest, CheckSettingMigrationStartDate) {
         migrationUUID,
         "donor-rs/localhost:12345",
         ReadPreferenceSetting(ReadPreference::PrimaryOnly, TagSet::primaryOnly()),
-        "tenantA");
+        "tenantA",
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setDonorCertificateForRecipient(kDonorPEMPayload);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
diff --git a/src/mongo/db/repl/tenant_migration_recipient_entry_helpers_test.cpp b/src/mongo/db/repl/tenant_migration_recipient_entry_helpers_test.cpp
index 980f5243591..6d2aa049d85 100644
--- a/src/mongo/db/repl/tenant_migration_recipient_entry_helpers_test.cpp
+++ b/src/mongo/db/repl/tenant_migration_recipient_entry_helpers_test.cpp
@@ -116,7 +116,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest, AddTenantMigrationRecipientStat
         "donor-rs0/localhost:12345",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     activeTenantAStateDoc.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_OK(insertStateDoc(opCtx.get(), activeTenantAStateDoc));
     ASSERT_TRUE(checkStateDocPersisted(opCtx.get(), activeTenantAStateDoc));
@@ -126,7 +127,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest, AddTenantMigrationRecipientStat
                                                "donor-rs1/localhost:12345",
                                                "tenantA",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc1.setRecipientCertificateForDonor(kRecipientPEMPayload);
     auto status = insertStateDoc(opCtx.get(), stateDoc1);
     ASSERT_EQUALS(ErrorCodes::ConflictingOperationInProgress, status.code());
@@ -137,7 +139,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest, AddTenantMigrationRecipientStat
                                                "donor-rs0/localhost:12345",
                                                "tenantB",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc2.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_THROWS_CODE(
         insertStateDoc(opCtx.get(), stateDoc2), DBException, ErrorCodes::DuplicateKey);
@@ -148,7 +151,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest, AddTenantMigrationRecipientStat
                                                "donor-rs0/localhost:12345",
                                                "tenantA",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc3.setRecipientCertificateForDonor(kRecipientPEMPayload);
     status = insertStateDoc(opCtx.get(), stateDoc3);
     ASSERT_EQUALS(ErrorCodes::ConflictingOperationInProgress, status.code());
@@ -159,7 +163,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest, AddTenantMigrationRecipientStat
                                                "donor-rs0/localhost:12345",
                                                "tenantB",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc4.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_OK(insertStateDoc(opCtx.get(), stateDoc4));
     ASSERT_TRUE(checkStateDocPersisted(opCtx.get(), stateDoc4));
@@ -175,7 +180,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest,
         "donor-rs0/localhost:12345",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     inactiveTenantAStateDoc.setRecipientCertificateForDonor(kRecipientPEMPayload);
     inactiveTenantAStateDoc.setExpireAt(Date_t::now());
     ASSERT_OK(insertStateDoc(opCtx.get(), inactiveTenantAStateDoc));
@@ -186,7 +192,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest,
                                                "donor-rs1/localhost:12345",
                                                "tenantA",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc1.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_THROWS_CODE(
         insertStateDoc(opCtx.get(), stateDoc1), DBException, ErrorCodes::DuplicateKey);
@@ -197,7 +204,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest,
                                                "donor-rs0/localhost:12345",
                                                "tenantB",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc2.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_THROWS_CODE(
         insertStateDoc(opCtx.get(), stateDoc2), DBException, ErrorCodes::DuplicateKey);
@@ -208,7 +216,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest,
                                                "donor-rs0/localhost:12345",
                                                "tenantA",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc3.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_OK(insertStateDoc(opCtx.get(), stateDoc3));
     ASSERT_TRUE(checkStateDocPersisted(opCtx.get(), stateDoc3));
@@ -218,7 +227,8 @@ TEST_F(TenantMigrationRecipientEntryHelpersTest,
                                                "donor-rs0/localhost:12345",
                                                "tenantC",
                                                kDefaultStartMigrationTimestamp,
-                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+                                               ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+                                               MigrationProtocolEnum::kMultitenantMigrations);
     stateDoc4.setRecipientCertificateForDonor(kRecipientPEMPayload);
     ASSERT_OK(insertStateDoc(opCtx.get(), stateDoc4));
     ASSERT_TRUE(checkStateDocPersisted(opCtx.get(), stateDoc4));
diff --git a/src/mongo/db/repl/tenant_migration_recipient_service.cpp b/src/mongo/db/repl/tenant_migration_recipient_service.cpp
index 9c23744955e..877fa85568c 100644
--- a/src/mongo/db/repl/tenant_migration_recipient_service.cpp
+++ b/src/mongo/db/repl/tenant_migration_recipient_service.cpp
@@ -306,6 +306,7 @@ TenantMigrationRecipientService::Instance::Instance(
       _stateDoc(TenantMigrationRecipientDocument::parse(IDLParserErrorContext("recipientStateDoc"),
                                                         stateDoc)),
       _tenantId(_stateDoc.getTenantId().toString()),
+      _protocol(_stateDoc.getProtocol()),
       _migrationUuid(_stateDoc.getId()),
       _donorConnectionString(_stateDoc.getDonorConnectionString().toString()),
       _donorUri(uassertStatusOK(MongoURI::parse(_stateDoc.getDonorConnectionString().toString()))),
@@ -409,7 +410,7 @@ Status TenantMigrationRecipientService::Instance::checkIfOptionsConflict(
     stdx::lock_guard<Latch> lg(_mutex);
     invariant(stateDoc.getId() == _migrationUuid);
 
-    if (stateDoc.getTenantId() == _tenantId &&
+    if (stateDoc.getProtocol() == _protocol && stateDoc.getTenantId() == _tenantId &&
         stateDoc.getDonorConnectionString() == _donorConnectionString &&
         stateDoc.getReadPreference().equals(_readPreference) &&
         stateDoc.getRecipientCertificateForDonor() == _recipientCertificateForDonor) {
@@ -2487,5 +2488,9 @@ const std::string& TenantMigrationRecipientService::Instance::getTenantId() cons
     return _tenantId;
 }
 
+const MigrationProtocolEnum TenantMigrationRecipientService::Instance::getProtocol() const {
+    return _protocol;
+}
+
 }  // namespace repl
 }  // namespace mongo
diff --git a/src/mongo/db/repl/tenant_migration_recipient_service.h b/src/mongo/db/repl/tenant_migration_recipient_service.h
index 4fbb25126a7..99ee45ba6d1 100644
--- a/src/mongo/db/repl/tenant_migration_recipient_service.h
+++ b/src/mongo/db/repl/tenant_migration_recipient_service.h
@@ -138,6 +138,11 @@ public:
          */
         const std::string& getTenantId() const;
 
+        /*
+         *  Returns the migration protocol.
+         */
+        const MigrationProtocolEnum getProtocol() const;
+
         /**
          * To be called on the instance returned by PrimaryOnlyService::getOrCreate(). Returns an
          * error if the options this Instance was created with are incompatible with the options
@@ -572,6 +577,7 @@ public:
         // This data is provided in the initial state doc and never changes.  We keep copies to
         // avoid having to obtain the mutex to access them.
         const std::string _tenantId;                                                     // (R)
+        const MigrationProtocolEnum _protocol;                                           // (R)
         const UUID _migrationUuid;                                                       // (R)
         const std::string _donorConnectionString;                                        // (R)
         const MongoURI _donorUri;                                                        // (R)
diff --git a/src/mongo/db/repl/tenant_migration_recipient_service_test.cpp b/src/mongo/db/repl/tenant_migration_recipient_service_test.cpp
index b30dee191a0..4eca8a03fb0 100644
--- a/src/mongo/db/repl/tenant_migration_recipient_service_test.cpp
+++ b/src/mongo/db/repl/tenant_migration_recipient_service_test.cpp
@@ -479,7 +479,8 @@ TEST_F(TenantMigrationRecipientServiceTest, BasicTenantMigrationRecipientService
         "donor-rs/localhost:12345",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly, TagSet::primaryOnly()));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly, TagSet::primaryOnly()),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -504,7 +505,8 @@ TEST_F(TenantMigrationRecipientServiceTest, InstanceReportsErrorOnFailureWhilePe
         "donor-rs/localhost:12345",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly, TagSet::primaryOnly()));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly, TagSet::primaryOnly()),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -539,7 +541,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientConnection_P
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -590,7 +593,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientConnection_S
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::SecondaryOnly));
+        ReadPreferenceSetting(ReadPreference::SecondaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -642,7 +646,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -700,7 +705,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -772,7 +778,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::Nearest));
+        ReadPreferenceSetting(ReadPreference::Nearest),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -833,7 +840,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryPreferred));
+        ReadPreferenceSetting(ReadPreference::PrimaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -902,7 +910,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryPreferred));
+        ReadPreferenceSetting(ReadPreference::PrimaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -974,7 +983,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::SecondaryOnly));
+        ReadPreferenceSetting(ReadPreference::SecondaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -1035,7 +1045,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::SecondaryPreferred));
+        ReadPreferenceSetting(ReadPreference::SecondaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Hang the migration before attempting to connect to clients.
@@ -1114,7 +1125,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryPreferred));
+        ReadPreferenceSetting(ReadPreference::PrimaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
     initialStateDocument.setStartApplyingDonorOpTime(startApplyingOpTime);
 
@@ -1172,7 +1184,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         startMigrationDonorTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryPreferred));
+        ReadPreferenceSetting(ReadPreference::PrimaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1233,7 +1246,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientConnection_P
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryPreferred));
+        ReadPreferenceSetting(ReadPreference::PrimaryPreferred),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1277,7 +1291,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientConnection_B
         "broken,connect,string,no,set,name",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1299,7 +1314,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         "localhost:12345",
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1325,7 +1341,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientGetStartOpTi
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1364,7 +1381,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1409,7 +1427,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientGetStartOpTi
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1456,7 +1475,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -1492,7 +1512,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.  Fail to populate the remote oplog mock.
@@ -1527,7 +1548,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientStartOplogFe
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     auto opCtx = makeOperationContext();
@@ -1582,7 +1604,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientStartsCloner
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     auto opCtx = makeOperationContext();
@@ -1637,7 +1660,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogFetcherFailsDuringOplogApplicat
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -1693,7 +1717,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogFetcherResumesFromTopOfOplogBuf
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -1800,7 +1825,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogFetcherNoDocInBufferToResumeFro
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -1909,7 +1935,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogApplierResumesFromLastNoOpOplog
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -2034,7 +2061,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -2207,7 +2235,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogApplierResumesFromStartDonorApp
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -2352,7 +2381,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // We skip cloning here as a way to simulate that the recipient service has detected an existing
@@ -2458,7 +2488,8 @@ TEST_F(TenantMigrationRecipientServiceTest, OplogApplierFails) {
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -2524,7 +2555,8 @@ TEST_F(TenantMigrationRecipientServiceTest, StoppingApplierAllowsCompletion) {
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -2579,7 +2611,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientAddResumeTok
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -2682,7 +2715,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_BeforeRun)
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     auto fp = globalFailPointRegistry().find("pauseBeforeRunTenantMigrationRecipientInstance");
@@ -2720,7 +2754,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_FailToIniti
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     auto opCtx = makeOperationContext();
@@ -2754,7 +2789,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_WaitUntilSt
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     auto fp = globalFailPointRegistry().find("pauseAfterRunTenantMigrationRecipientInstance");
@@ -2838,7 +2874,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_AfterStartO
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -2901,7 +2938,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_AfterConsis
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -2989,7 +3027,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_AfterFail)
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -3071,7 +3110,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientForgetMigration_FailToMarkG
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3123,7 +3163,8 @@ TEST_F(TenantMigrationRecipientServiceTest, TenantMigrationRecipientServiceRecor
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3158,7 +3199,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Add an FCV value as if it was from a previous attempt.
@@ -3197,7 +3239,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Add an FCV value as if it was from a previous attempt, making sure we set a different
@@ -3244,7 +3287,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3279,7 +3323,8 @@ TEST_F(TenantMigrationRecipientServiceTest, WaitUntilMigrationReachesReturnAfter
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Skip the cloners in this test, so we provide an empty list of databases.
@@ -3339,7 +3384,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientReceivesRetriableFetcherErr
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3403,7 +3449,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientReceivesNonRetriableFetcher
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3462,7 +3509,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientWillNotRetryOnExternalInter
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3520,7 +3568,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientReceivesRetriableClonerErro
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3592,7 +3641,8 @@ TEST_F(TenantMigrationRecipientServiceTest, RecipientReceivesNonRetriableClonerE
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
 
     // Create and start the instance.
@@ -3646,7 +3696,8 @@ TEST_F(TenantMigrationRecipientServiceTest, IncrementNumRestartsDueToRecipientFa
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
     // Starting a migration where the state is not 'kUninitialized' indicates that we are restarting
     // from failover.
@@ -3697,7 +3748,8 @@ TEST_F(TenantMigrationRecipientServiceTest,
         replSet.getConnectionString(),
         "tenantA",
         kDefaultStartMigrationTimestamp,
-        ReadPreferenceSetting(ReadPreference::PrimaryOnly));
+        ReadPreferenceSetting(ReadPreference::PrimaryOnly),
+        MigrationProtocolEnum::kMultitenantMigrations);
     initialStateDocument.setRecipientCertificateForDonor(kRecipientPEMPayload);
     // Starting a migration where the state is not 'kUninitialized' indicates that we are restarting
     // from failover.
diff --git a/src/mongo/db/repl/tenant_migration_state_machine.idl b/src/mongo/db/repl/tenant_migration_state_machine.idl
index f8a6291d5a6..fb0644bfeaf 100644
--- a/src/mongo/db/repl/tenant_migration_state_machine.idl
+++ b/src/mongo/db/repl/tenant_migration_state_machine.idl
@@ -36,6 +36,7 @@ imports:
     - "mongo/client/read_preference_setting.idl"
     - "mongo/db/repl/replication_types.idl"
     - "mongo/db/repl/tenant_migration_pem_payload.idl"
+    - "mongo/db/serverless/serverless_types.idl"
     - "mongo/idl/basic_types.idl"
 
 enums:
@@ -137,6 +138,9 @@ structs:
                 description: >-
                     The wall-clock time at which the migration has started.
                 optional: true
+            protocol:
+                description: "Which migration protocol to use."
+                type: MigrationProtocol
 
     tenantMigrationRecipientDocument:
         description: "Represents an in-progress tenant migration on the migration recipient."
@@ -171,6 +175,9 @@ structs:
                 description: >-
                     The read preference setting that the recipient will use to determine
                     which node in the donor replica set to clone from.
+            protocol:
+                description: "Which migration protocol to use."
+                type: MigrationProtocol
             state:
                 type: TenantMigrationRecipientState
                 description: "The state of the tenant migration."
diff --git a/src/mongo/db/repl/tenant_migration_util.h b/src/mongo/db/repl/tenant_migration_util.h
index 18d303d6984..29fef1c44fe 100644
--- a/src/mongo/db/repl/tenant_migration_util.h
+++ b/src/mongo/db/repl/tenant_migration_util.h
@@ -38,7 +38,9 @@
 #include "mongo/db/catalog/database.h"
 #include "mongo/db/keys_collection_document_gen.h"
 #include "mongo/db/pipeline/pipeline.h"
+#include "mongo/db/repl/repl_server_parameters_gen.h"
 #include "mongo/db/repl/replication_coordinator.h"
+#include "mongo/db/serverless/serverless_types_gen.h"
 #include "mongo/executor/scoped_task_executor.h"
 #include "mongo/util/net/ssl_util.h"
 #include "mongo/util/str.h"
@@ -128,6 +130,34 @@ inline Status validatePrivateKeyPEMPayload(const StringData& payload) {
 #endif
 }
 
+inline void protocolCompatibilityCheck(const MigrationProtocolEnum protocol,
+                                       const std::string& tenantId) {
+    switch (protocol) {
+        case MigrationProtocolEnum::kShardMerge: {
+            uassert(ErrorCodes::IllegalOperation,
+                    str::stream() << "protocol '" << MigrationProtocol_serializer(protocol)
+                                  << "' not supported",
+                    repl::feature_flags::gShardMerge.isEnabled(
+                        serverGlobalParams.featureCompatibility));
+
+            // TODO: SERVER-59495 Add a check to ensure tenantId is not provided for 'Merge'
+            // protocol.
+            break;
+        }
+        case MigrationProtocolEnum::kMultitenantMigrations: {
+            uassert(ErrorCodes::InvalidOptions,
+                    str::stream() << "'tenantId' is required for protocol '"
+                                  << MigrationProtocol_serializer(protocol) << "'",
+                    !tenantId.empty());
+
+
+            break;
+        }
+        default:
+            MONGO_UNREACHABLE;
+    }
+}
+
 /*
  * Creates an ExternalKeysCollectionDocument representing an config.external_validation_keys
  * document from the given the admin.system.keys document BSONObj.
diff --git a/src/mongo/db/serverless/SConscript b/src/mongo/db/serverless/SConscript
index 0f3259271f6..b2ebb792ae7 100644
--- a/src/mongo/db/serverless/SConscript
+++ b/src/mongo/db/serverless/SConscript
@@ -4,6 +4,18 @@ Import("env")
 env = env.Clone()
 
 env.Library(
+    target='serverless_types_idl',
+    source=[
+        'serverless_types.idl',
+    ],
+    LIBDEPS=[
+        '$BUILD_DIR/mongo/base',
+        '$BUILD_DIR/mongo/idl/basic_types',
+        '$BUILD_DIR/mongo/idl/idl_parser'
+    ],
+)
+
+env.Library(
     target='tenant_split_state_machine',
     source=[
         'tenant_split_state_machine.idl',
diff --git a/src/mongo/db/serverless/serverless_types.idl b/src/mongo/db/serverless/serverless_types.idl
new file mode 100644
index 00000000000..e906e7a52c3
--- /dev/null
+++ b/src/mongo/db/serverless/serverless_types.idl
@@ -0,0 +1,40 @@
+# Copyright (C) 2021-present MongoDB, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the Server Side Public License, version 1,
+# as published by MongoDB, Inc.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# Server Side Public License for more details.
+#
+# You should have received a copy of the Server Side Public License
+# along with this program. If not, see
+# <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the Server Side Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+#
+global:
+    cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+enums:
+    MigrationProtocol:
+        description: "Determines which tenant migration protocol to use."
+        type: string
+        values:
+            kMultitenantMigrations: "multitenant migrations"
+            kShardMerge: "shard merge"