Hans, Thanks for reading it. Comments inline.
>Date: Mon, 20 Jun 2016 16:34:32 +0200 >From: Hans Seidel <[email protected]> > >Sabine, Wendy, > >Below, my comments/questions on draft-ietf-alto-multi-cost-02.txt. > >S4.1.2 "constraints" paragraph: > >If I get this correct, in case "max-cost-types" > 0 and extended >predicates are used, the logical OR applies instead of logical AND. >Why changing the behavior? Is there an advantage in using the logical OR? The intent is that if the server is multi-cost-aware (i.e., max-cost-types > 0), then a client can use *either* an or-constraints parameter or a >constraints parameter. So we extended the behavior, rather than changing >it. If a simple AND test is sufficient for the client, the client can use "constraints". There is no advantage to using or-constraints unless the client needs the OR of ANDs. The two parameters are mutually exclusive, and I assume a multi-cost-aware server will interpret a constraints parameter as just a short-cut for or-constraints. >What is used if no extended predicates are used, for example when a >legacy client is requesting a multi-cost resource? >I assume the logical AND as stated in RFC7285 but it is not entirely >clear to me. The intent is to be strictly upward compatible: multi-cost-aware servers will accept RFC 7285 predicates. We will look it over to see if we can make that clearer. And we would welcome any suggestions as to how to clarify that. >How can a server distinguish between RFC7285 predicates and the new >extended predicates? >Here, I am especially thinking of the case, that cost type index "0" can >be omitted and the extended predicate becomes indistinguishable from >RFC7285 predicates. We designed the extended predicates to an extension of the RFC7285 predicates. Because the index is optional, and defaults to 0, a multi-cost-aware server will interpret an RFC7285 constraint like le 10 as [0] le 10. So strictly speaking, a multi-cost-aware server does not need to distinguish between an extended predicate and an RFC 7285 predicate. >In general, I noticed some upper/lower case inconsistencies for certain >nouns on several occasions. E.g. "client" and "Client" or "endpoint" and >"Endpoint". >For consistency reasons only one notation should be used. *Sigh* Yes, I know. We will look it over and clean it up. Although I think RFC7285 had similar inconsistencies. >Regards >Hans Thanks for the comments. - Wendy _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
