[ratelimits] rate limit counters

[paul vixie]

On 7/8/2012 1:14 AM, Vernon Schryver wrote:
> In the current version of the BIND9 rate limit patch, responses
> dropped for rate limiting are counted among "Name Server Statistics"
> as "queries dropped".  The `rndc stats` command dumps current
> counters to to a file.  If the "statistics-file" option is not used,
> the default is named.stats in the server's current directory.
>
> See QryDropped in the discussion of "Statistics Counters" in the ARM
> perhaps at
> http://ftp.isc.org/isc/bind9/cur/9.9/doc/arm/Bv9ARM.ch06.html#statistics_counters
>
> The QryDropped counter is also incremented for excessive recursive queries
> as described in that section and in
> http://ftp.isc.org/isc/bind9/cur/9.9/doc/arm/Bv9ARM.ch06.html#clients-per-query

i don't think we should overload this counter to include this new kind
of droppage.

> Responses that are "slipped" or answered with a truncated or TC=1
> result for rate limiting are included in the RespTruncated counter
> with responses that are truncated because they would be too large.

likewise.

> My question is whater that is that good enough?  Must there be
> separate counters for responses dropped or truncated for rate
> limiting?  My inclination is to say that it is good enough.

i think we need two new counters, RateDropped and RateSlipped.

paul