SERVER-24856 Make manual moveChunk requests go through the balancer on CSRS primary

3 files changed, 11 insertions, 5 deletions

diff --git a/src/mongo/db/s/active_migrations_registry.cpp b/src/mongo/db/s/active_migrations_registry.cpp
index 62d9d287f5a..70e69a05f66 100644
--- a/src/mongo/db/s/active_migrations_registry.cpp
+++ b/src/mongo/db/s/active_migrations_registry.cpp
@@ -55,7 +55,7 @@ StatusWith<ScopedRegisterMigration> ActiveMigrationsRegistry::registerMigration(
 
     return {ErrorCodes::ConflictingOperationInProgress,
             str::stream()
-                << "Unable start new migration, because there is already an active migration for "
+                << "Unable start new migration because this shard is currently donating chunk for "
                 << _activeMoveChunkState->args.getNss().ns()};
 }
 
diff --git a/src/mongo/db/s/migration_destination_manager_legacy_commands.cpp b/src/mongo/db/s/migration_destination_manager_legacy_commands.cpp
index 545925f7190..6c528147df9 100644
--- a/src/mongo/db/s/migration_destination_manager_legacy_commands.cpp
+++ b/src/mongo/db/s/migration_destination_manager_legacy_commands.cpp
@@ -95,10 +95,9 @@ public:
 
         // Active state of TO-side migrations (MigrateStatus) is serialized by distributed
         // collection lock.
-        if (shardingState->migrationDestinationManager()->isActive()) {
-            errmsg = "migrate already in progress";
-            return false;
-        }
+        uassert(ErrorCodes::ConflictingOperationInProgress,
+                "Shard is already serving as a destination for migration",
+                !shardingState->migrationDestinationManager()->isActive());
 
         // Pending deletes (for migrations) are serialized by the distributed collection lock,
         // we are sure we registered a delete for a range *before* we can migrate-in a
diff --git a/src/mongo/db/s/sharding_state.cpp b/src/mongo/db/s/sharding_state.cpp
index 999f74a6be0..b1982ee4f58 100644
--- a/src/mongo/db/s/sharding_state.cpp
+++ b/src/mongo/db/s/sharding_state.cpp
@@ -659,6 +659,13 @@ StatusWith<ChunkVersion> ShardingState::_refreshMetadata(
 }
 
 StatusWith<ScopedRegisterMigration> ShardingState::registerMigration(const MoveChunkRequest& args) {
+    if (_migrationDestManager.isActive()) {
+        return {
+            ErrorCodes::ConflictingOperationInProgress,
+            str::stream()
+                << "Unable start new migration because this shard is currently receiving a chunk"};
+    }
+
     return _activeMigrationsRegistry.registerMigration(args);
 }