[RFC - Request for Comments] Removal of Squid external DNS helper API

As mentioned in the subject this is a call for feedback regarding the 
prospect of removing the external DNS helper component from Squid and 
its associated "dnsserver" binary.

To most of you this will be known as the "--disable-internal-dns" build 
option.

Background:
   The external helper was added back in the early 2.x releases to 
provide Squid with a flexible DNS lookup and attain such high speeds as 
250 requests per second. The external helper has since been replaced by 
an internal DNS resolver component which is much more performant and can 
handle several thousands of requests per second, higher than that of any 
other component in Squid and effetively removing DNS as a contention 
point in the processing.

The external helper has been officially deprecated in Squid-2.7 and 
Squid-3.0 for all installations which require only global DNS 
resolution. However, system resolvers which are used by the dnsserver 
helper typically offer DNS resolution using a number of mechanisms 
beyond global DNS (mDNS, Bonjour, NetBIOS, WINS, etc) and we are aware 
that installations exist relying on these additional services.


Given some recent advancements:
  * The world has moved on from services such as NetBIOS and WINS
  * Bonjour has grown up into mDNS
  * The upcoming Squid-3.4 series internal DNS resolver will right now 
support both global DNS and local multicast DNS (mDNS).


The question to you in the community from myself as Squid-3 maintainer, 
is whether global DNS and mDNS resolver queries are sufficient to meet 
your needs?

If the consensus is that the upcoming 3.4 series internal resolver is 
sufficiently featured to be used in all the current network 
installations of Squid we may finally be in a position to remove the 
deprecated component entirely in 3.4.

If you are in any way reliant on the dnsserver helper for DNS service or 
runnign a custom-built helper in its place, please do speak up.

I look forward to your feedback, which may be posted to the squid-users 
mailing list copy of this message or if you require privacy for any 
reason you may contact me directly about this.

Amos Jeffries