On Mar  5 08:34, Warren Young wrote:
> On 3/4/2014 01:07, Corinna Vinschen wrote:
> >On Mar  3 22:07, Warren Young wrote:
> >>
> >>You have to measure it to find out.
> >
> >I was inclined to go with Andrey's suggestion for simplicity.  What's
> >yours?
> 
> Science!
> 
> Survey actual lookup times, and make a statistical determination
> from that.  e.g. +3 sigma[1] above the normal to capture > 99% of
> the Cygwin user base, or +6 sigma to reduce outliers to the order of
> 2 ppm.
> 
> To collect the data, instrument the DLL and report anonymous
> statistics back to cygwin.com if the user opts in via setup.exe.
> 
> Rather than report back continually, just keep a model of the lookup
> time[2], and report the current lookup time average on each
> setup.exe run, such as in the HTTP request for the mirror list:
> 
>     GET /mirrors.lst?adluavg=123
> 
> That is, setup.exe is reporting that the typical AD lookup time at
> this site is currently 123 ms.
> 
> Note that you don't have to write a CGI program to accomplish this.
> Apache will continue to serve static mirror.lst files for you with
> the GET parameter.[3]  It will dutifully log each query to
> access_log, and you can dig the reported lookup time values out of
> the file when you want to compile your statistics.
> 
> When calculating statistics, use only the latest value for each
> reporting IP, so that sites that update Cygwin more often don't skew
> the results.
> 
> The default timeout should be baked into the DLL, but overridable in
> nsswitch.conf, with ms resolution.

You're kidding, aren't you?  Apart from that, ms are not useful since
LDAP_OPT_TIMELIMIT used for ldap_bind_s only takes values in 1 second
resolution.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat