disable SHUTDOWN in distributed mode

src/common/backend/parser/gram.y

@@ -1077,7 +1077,7 @@ stmt :
 			| RuleStmt
 			| SecLabelStmt
 			| SelectStmt
-                        | ShutdownStmt
+			| ShutdownStmt
 			| TransactionStmt
 			| TruncateStmt
 			| UnlistenStmt

src/gausskernel/optimizer/commands/shutdown.cpp

@@ -29,6 +29,10 @@
 
 void DoShutdown(ShutdownStmt* stmt)
 {
+#ifdef ENABLE_MULTIPLE_NODES
+    ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("SHUTDOWN is not supported in distributed mode.")));
+#endif
+
     if (!superuser()) {
         ereport(ERROR,
             (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), (errmsg("Only system admin can shutdown database."))));