ion of application traffic are handed off to an external proxy through the socket delegation mechanism discussed earlier. It uses an extended version of <a href=https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt>proxy protocol</a>. In addition to the simple parameters supported by the proxy protocol, a variety of other metadata (including the initial protocol headers obtained from the socket buffers) and live socket FDs (representing application connections) are forwarded to the proxy.</p><p>The pr