On Tue, Jul 12, 2016 at 8:45 AM, John R Levine <jo...@taugh.com> wrote: >>> My main suggestion is to lose the Proxy-DNS-Transport header and >>> always have the request and response in TCP format. >> >> >> The HTTP payload should always be unframed (like DNS over UDP) regardless >> of the upstream DNS transport, since HTTP already provides content-length >> framing so there's no need to repeat the message length. Like TCP, the >> EDNS0 UDP buffer size is irrelevant for HTTP. > > > The reason to use TCP framing is so that you can send multiple DNS requests > in a single http request and get back multiple answers. Recent messages > here suggest that's of considerable interest, and if you're only sending one > request, the two bytes of TCP length are tiny compared to the http headers.
Maybe I'm still missing something - so you pack multiple DNS requests in single HTTP request, answer#1 takes 5s, answer#2 timeouts, the rest is answered from cache. How do you send back the fast answers first without blocking when you have just a single HTTP request outstanding? > It occurs to me that this crock is not inherently much slower than regular > TCP over DNS. In both cases the client opens a connection and sends out the > request, and the server sends back the answer. In both DNS and most > versions of http you can leave the connection open and reuse it, probably > more important in http since you're likely reusing the TLS negotiation too. > > Regards, > John Levine, jo...@taugh.com, Taughannock Networks, Trumansburg NY > Please consider the environment before reading this e-mail. > > _______________________________________________ > DNSOP mailing list > DNSOP@ietf.org > https://www.ietf.org/mailman/listinfo/dnsop _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
