feat: add SAVE MYSQLX handlers and first-class LOAD/SAVE dispatch

Replace the PLUGIN MYSQLX command namespace with canonical ProxySQL
admin syntax matching the MYSQL/PGSQL convention.

Plugin changes (mysqlx_admin_schema.cpp):
- Add three SAVE handlers (save_users_from_runtime,
  save_routes_from_runtime, save_backend_endpoints_from_runtime) that
  copy runtime tables back to config tables (reverse of LOAD)
- Register 6 commands with canonical names:
  LOAD MYSQLX USERS/ROUTES/BACKEND ENDPOINTS TO RUNTIME
  SAVE MYSQLX USERS/ROUTES/BACKEND ENDPOINTS TO MEMORY

Admin handler changes (Admin_Handler.cpp):
- Add 6 MYSQLX alias vector definitions following the existing
  LOAD_MYSQL_USERS_FROM_MEMORY pattern (4 aliases each: FROM MEMORY,
  FROM MEM, TO RUNTIME, TO RUN)
- Replace the generic plugin fallback dispatch with MYSQLX-specific
  alias matching using is_admin_command_or_alias(), matching how
  MYSQL and PGSQL commands are dispatched
- Use 'return false' pattern consistent with other admin commands

lib/Admin_Handler.cpp

@@ -313,6 +313,43 @@ const std::vector<std::string> SAVE_TSDB_VARIABLES_TO_MEMORY = {
 	"SAVE TSDB VARIABLES TO MEM" ,
 	"SAVE TSDB VARIABLES FROM RUNTIME" ,
 	"SAVE TSDB VARIABLES FROM RUN" };
+
+// MySQLX plugin
+const std::vector<std::string> LOAD_MYSQLX_USERS_FROM_MEMORY = {
+	"LOAD MYSQLX USERS FROM MEMORY" ,
+	"LOAD MYSQLX USERS FROM MEM" ,
+	"LOAD MYSQLX USERS TO RUNTIME" ,
+	"LOAD MYSQLX USERS TO RUN" };
+
+const std::vector<std::string> SAVE_MYSQLX_USERS_TO_MEMORY = {
+	"SAVE MYSQLX USERS TO MEMORY" ,
+	"SAVE MYSQLX USERS TO MEM" ,
+	"SAVE MYSQLX USERS FROM RUNTIME" ,
+	"SAVE MYSQLX USERS FROM RUN" };
+
+const std::vector<std::string> LOAD_MYSQLX_ROUTES_FROM_MEMORY = {
+	"LOAD MYSQLX ROUTES FROM MEMORY" ,
+	"LOAD MYSQLX ROUTES FROM MEM" ,
+	"LOAD MYSQLX ROUTES TO RUNTIME" ,
+	"LOAD MYSQLX ROUTES TO RUN" };
+
+const std::vector<std::string> SAVE_MYSQLX_ROUTES_TO_MEMORY = {
+	"SAVE MYSQLX ROUTES TO MEMORY" ,
+	"SAVE MYSQLX ROUTES TO MEM" ,
+	"SAVE MYSQLX ROUTES FROM RUNTIME" ,
+	"SAVE MYSQLX ROUTES FROM RUN" };
+
+const std::vector<std::string> LOAD_MYSQLX_BACKEND_ENDPOINTS_FROM_MEMORY = {
+	"LOAD MYSQLX BACKEND ENDPOINTS FROM MEMORY" ,
+	"LOAD MYSQLX BACKEND ENDPOINTS FROM MEM" ,
+	"LOAD MYSQLX BACKEND ENDPOINTS TO RUNTIME" ,
+	"LOAD MYSQLX BACKEND ENDPOINTS TO RUN" };
+
+const std::vector<std::string> SAVE_MYSQLX_BACKEND_ENDPOINTS_TO_MEMORY = {
+	"SAVE MYSQLX BACKEND ENDPOINTS TO MEMORY" ,
+	"SAVE MYSQLX BACKEND ENDPOINTS TO MEM" ,
+	"SAVE MYSQLX BACKEND ENDPOINTS FROM RUNTIME" ,
+	"SAVE MYSQLX BACKEND ENDPOINTS FROM RUN" };
 //
 const std::vector<std::string> LOAD_COREDUMP_FROM_MEMORY = {
 	"LOAD COREDUMP FROM MEMORY" ,
@@ -5298,9 +5335,17 @@ __end_show_commands:
 	}
 	if (run_query && sess->session_type == PROXYSQL_SESSION_ADMIN) {
 		ProxySQL_Admin *SPA=(ProxySQL_Admin *)pa;
-		if (SPA->dispatch_plugin_admin_command(sess, query_no_space)) {
-			run_query=false;
-			goto __run_query;
+		if (
+			is_admin_command_or_alias(LOAD_MYSQLX_USERS_FROM_MEMORY, query_no_space, query_no_space_length) ||
+			is_admin_command_or_alias(SAVE_MYSQLX_USERS_TO_MEMORY, query_no_space, query_no_space_length) ||
+			is_admin_command_or_alias(LOAD_MYSQLX_ROUTES_FROM_MEMORY, query_no_space, query_no_space_length) ||
+			is_admin_command_or_alias(SAVE_MYSQLX_ROUTES_TO_MEMORY, query_no_space, query_no_space_length) ||
+			is_admin_command_or_alias(LOAD_MYSQLX_BACKEND_ENDPOINTS_FROM_MEMORY, query_no_space, query_no_space_length) ||
+			is_admin_command_or_alias(SAVE_MYSQLX_BACKEND_ENDPOINTS_TO_MEMORY, query_no_space, query_no_space_length)
+		) {
+			if (SPA->dispatch_plugin_admin_command(sess, query_no_space)) {
+				return false;
+			}
 		}
 	}
 

plugins/mysqlx/src/mysqlx_admin_schema.cpp

@@ -164,6 +164,48 @@ ProxySQL_PluginCommandResult load_backend_endpoints_to_runtime(const ProxySQL_Pl
 	return result;
 }
 
+ProxySQL_PluginCommandResult save_users_from_runtime(const ProxySQL_PluginCommandContext& ctx, const char*) {
+	if (ctx.admindb == nullptr) {
+		return command_failure("mysqlx users save requires admin db");
+	}
+	if (!copy_table(*ctx.admindb, kRuntimeMysqlxUsersTable, kMysqlxUsersTable)) {
+		return command_failure("failed to copy mysqlx users from runtime");
+	}
+
+	ProxySQL_PluginCommandResult result {0, 0, ""};
+	result.rows_affected = ctx.admindb->return_one_int("SELECT COUNT(*) FROM mysqlx_users");
+	result.message = "mysqlx users saved from runtime";
+	return result;
+}
+
+ProxySQL_PluginCommandResult save_routes_from_runtime(const ProxySQL_PluginCommandContext& ctx, const char*) {
+	if (ctx.admindb == nullptr) {
+		return command_failure("mysqlx routes save requires admin db");
+	}
+	if (!copy_table(*ctx.admindb, kRuntimeMysqlxRoutesTable, kMysqlxRoutesTable)) {
+		return command_failure("failed to copy mysqlx routes from runtime");
+	}
+
+	ProxySQL_PluginCommandResult result {0, 0, ""};
+	result.rows_affected = ctx.admindb->return_one_int("SELECT COUNT(*) FROM mysqlx_routes");
+	result.message = "mysqlx routes saved from runtime";
+	return result;
+}
+
+ProxySQL_PluginCommandResult save_backend_endpoints_from_runtime(const ProxySQL_PluginCommandContext& ctx, const char*) {
+	if (ctx.admindb == nullptr) {
+		return command_failure("mysqlx backend endpoints save requires admin db");
+	}
+	if (!copy_table(*ctx.admindb, kRuntimeMysqlxBackendEndpointsTable, kMysqlxBackendEndpointsTable)) {
+		return command_failure("failed to copy mysqlx backend endpoints from runtime");
+	}
+
+	ProxySQL_PluginCommandResult result {0, 0, ""};
+	result.rows_affected = ctx.admindb->return_one_int("SELECT COUNT(*) FROM mysqlx_backend_endpoints");
+	result.message = "mysqlx backend endpoints saved from runtime";
+	return result;
+}
+
 void register_table_pair(
 	ProxySQL_PluginServices& services,
 	const char* table_name,
@@ -259,8 +301,11 @@ bool mysqlx_register_admin_schema(ProxySQL_PluginServices& services) {
 		services.register_table(stats_processlist);
 	}
 
-	services.register_command("PLUGIN MYSQLX LOAD USERS TO RUNTIME", &load_users_to_runtime);
-	services.register_command("PLUGIN MYSQLX LOAD ROUTES TO RUNTIME", &load_routes_to_runtime);
-	services.register_command("PLUGIN MYSQLX LOAD BACKEND ENDPOINTS TO RUNTIME", &load_backend_endpoints_to_runtime);
+	services.register_command("LOAD MYSQLX USERS TO RUNTIME", &load_users_to_runtime);
+	services.register_command("SAVE MYSQLX USERS TO MEMORY", &save_users_from_runtime);
+	services.register_command("LOAD MYSQLX ROUTES TO RUNTIME", &load_routes_to_runtime);
+	services.register_command("SAVE MYSQLX ROUTES TO MEMORY", &save_routes_from_runtime);
+	services.register_command("LOAD MYSQLX BACKEND ENDPOINTS TO RUNTIME", &load_backend_endpoints_to_runtime);
+	services.register_command("SAVE MYSQLX BACKEND ENDPOINTS TO MEMORY", &save_backend_endpoints_from_runtime);
 	return true;
 }