[FEAT MERGE] system resource optimization

Co-authored-by: tushicheng <18829573815@163.com>
Co-authored-by: HaHaJeff <jeffzhouhhh@gmail.com>
Co-authored-by: dimstars <liangjinrongcm@gmail.com>

mittest/simple_server/env/ob_simple_cluster_test_base.cpp

@@ -161,7 +161,6 @@ int ObSimpleClusterTestBase::start()
   GCONF.enable_perf_event = false;
   GCONF.enable_sql_audit = true;
   GCONF.enable_record_trace_log = false;
-  GMEMCONF.set_server_memory_limit(10 * 1024  * 1024 * 1024ul);
 
   int32_t log_level;
   bool change_log_level = false;