`total_memory_tracker.setOrRaiseHardLimit(...);` in `ConfigReloader` callback (see `Server.cpp`).
LOG_INFO(log, "It looks like the process has no CAP_IPC_LOCK capability, binary mlock will be disabled."
                    " It could happen due to incorrect ClickHouse package installation."
                    " You could resolve the problem manually with 'sudo setcap cap_ipc_lock=+ep {}'."
                    " Note that it will not work on 'nosuid' mounted filesystems.", executable_path);
            }
        }
    }
#endif
    global_context->setRemoteHostFilter(config());
    std::string path = getCanonicalPath(config().getString("path", DBMS_DEFAULT_PATH));
    std::string default_database = config().getString("default_database", "default");
    
    const auto effective_user_id = geteuid();
    struct stat statbuf;
    if (stat(path.c_str(), &statbuf) == 0 && effective_user_id != statbuf.st_uid)
    {
        const auto effective_user = getUserName(effective_user_id);
        const auto data_owner = getUserName(statbuf.st_uid);
        std::string message = "Effective user of the process (" + effective_user +
            ") does not match the owner of the data (" + data_owner + ").";
        if (effective_user_id == 0)
        {
            message += " Run under 'sudo -u " + data_owner + "'.";
            throw Exception(message, ErrorCodes::MISMATCHING_USERS_FOR_PROCESS_AND_DATA);
        }
        else
        {
            LOG_WARNING(log, message);
        }
    }