On Thu, Nov 20, 2008 at 11:00 PM, Grayson Piercee <graysonpierce / yahoo.com> wrote: > I'm trying to do a home grown load balancing solution that needs to > determine which of the two data centers a visitor should be sent to. > I'd like to do some type of a network proximity calculation that > includes latency and number of hops which will allow me to redirect the > user to their "closest/fastest" server. > > I know all about CDNs and Appliance Load Balancers (F5); I'm looking for > a custom software solution instead. > > Any pointers is much appreciated. traceroute -n -w 1 -q 1 $USER | awk '{sum += $3} END { printf ("%8.2f\n",sum)}' ;-) Depending on how much time you can burn up front, one option may be to query the user's IP address via a geo-ip-location; perhaps cache the result based on either the user's full IP address or class C subnet to reduce the external API calls. Maybe traceroute and/or ping from each data center and geo-locate, caching all the results?