> one can lookup A, AAAA and SRV in parallel and positive answer > to SRV, as Paul mentioned, can have additional A and AAAA RRs.
A downside is that clients has to wait for the SRV query to complete so they can be sure of the presence or not of an SRV. First-win approaches like happy eyeballs don't work here so most clients are going to perform at the rate of negative cache lookups for the foreseeable future. In aggregate I would expect this will slow clients a bit. You're also ensuring that the global query rate will substantially increase on the assumption that HTTP/2.0 becomes as popular as HTTP/1.0. Generally speaking, the challenge is that SRV is likely acceptable to commercial CDN providers that have thus far relied on CNAME - with it's intrinsic level of indirection - but will be less welcome by those who are using every trick to squeeze latency out of HTTP. The latter - who are well represented in http-wg - will probably not welcome a parallel SRV even if the latency impact is mostly zero. If you want to make everyone happy, you need to invent a single round-trip resolution that supports indirection... These are just observations - not judgments. Mark. _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
