"reasonable" bulk resolver behavior

[Barry Margolin]

In article <cs5an6$21pm$1 at sf1.isc.org>,
 Steve Friedl <steve at unixwiz.net> wrote:

> Barry Margolin:
> > It depends on how powerful and busy the nameserver you're querying is.  
> > If you're running your own nameserver and it doesn't have lots of other 
> > clients, you may be able to go full out; if you're querying your ISP's 
> > nameserver, you'll probably have to throttle down quite a bit.
> 
> In my particular case, I control the nameserver (it's on localhost), but
> I wish to release this as a generic tool, and in order to be responsible
> I need to set some kind of default value that the "Joe Users" get (all
> five of them, probably) when they install the software without thinking
> about it. If I pick too few, it's no better than synchronous resolving.
> If too many, then I'm a resource hog.
> 
> My inclination is "40 or so".

Perhaps you could implement an adaptive algorithm, similar to TCP's 
congestion avoidance mechanism.  Start slow, and speed up until you 
notice a significant increase in response time, and then back off.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***