`total_memory_tracker.setOrRaiseHardLimit(...);` in `ConfigReloader` callback (see `Server.cpp`).
const Poco::Util::AbstractConfiguration & config,
    const std::string & config_path,
    const std::string & users_config_path,
    Poco::Logger * log)
{
    if (config.getBool("skip_check_for_incorrect_settings", false))
        return;
    if (config.has("users") || config.has("profiles") || config.has("quotas"))
    {
        
        
        LOG_ERROR(log, "The <users>, <profiles> and <quotas> elements should be located in users config file: {} not in main config {}."
            " Also note that you should place configuration changes to the appropriate *.d directory like 'users.d'.",
            users_config_path, config_path);
    }
}
int Server::main(const std::vector<std::string> & )