static String tryGetLoopbackURL(String url) {
        try {
            URI uri = new URI(url);
            String localHostName = RemotingUtils.getLocalHost();
            if (uri.getHost().equals(localHostName)) {
                // replace url with loopback connection
                url = uri.getScheme() + "://localhost:" + uri.getPort();
            }
        }
        catch (Exception e) {
            // ignore
        }
        return url;
    }
Whether to enable loopback connection for metaq client, default is false.
metamorphosis-client/src/main/java/com/taobao/metamorphosis/client/RemotingClientWrapper.java