On 9/12/13 1:39 PM, Rubens Kuhl wrote:
ICANN new gTLD agreements specified 100% availability for the service, meaning at least 2 DNS IP addresses answered 95% of requests within 500 ms (UDP) or 1500 ms (TCP) for 51+% of the probes, or 99% availability for a single name server, defined as 1 DNS IP address.
unless phil happens to be building out (or spec'ing out $provider's offered sla) for one of the happy thousand or so celebrants of 2014, a surprisingly large fraction of which are tenant plays on existing infrastructure, the bogie above, uninterpreted, is not a controlling authority. additionally, was phil asking for a metric for an authoritative server, serving a zone delegated directly from the iana root? was he asking for a metric for a caching server? and if the metric is "queries completed vs. queries lost", from where to where? (that is the "uninterpreted" bit from the bogie rubens quotes, as we did have to correct some assumptions of the requirement author -- where is the measurement being preformed? i'm with randy on this, dns is a service, the better question is what fails as query response degrades, in the presence of hierarchical caching and the protocol being used as designed under best effort of infrastructure and application. eric