Search Again: effects of real low TTL ???? From: Joseph D''Andrea Date: Wednesday, November 7, 2001 Time: 5:57:10 pm We've got an interesting scenario. A client in the UK has a web site that is tied to the UK release of the movie Shrek. We have the site loaded on two web servers and are load balancing between them. So far all is well. However, in a day or so, one of the largest ISPs in the UK with have a pop-up ad or some other mass advertisement for the site. We expect a significant number of people to visit just from this one provider alone. Since all of the people who use this provider presumably have the same DNS servers listed in their network setup, load balancing will not be very effective. In other words, the first person to visit the site will force the ISP to grab the IP address of the site, and every client after that from that same ISP will go to the same IP address because the IP address is cached in the ISP's DNS server. Now there will be lots of other people visiting the site from other ISPs, so there will be /some/ load balancing going on. What I'm thinking is that if I set the TTL of the domain real low... say one hour; and if the ISP respects the TTL and flushes its cache after that hour; then the next visitor from that ISP will force a new query and we'll have a 50/50 chance of it being the other server this time around. And so on and so on until the traffic dies down. Clearly there is some disadvantage to expiring an otherwise valid zone information just to force re-lookups... but are there other consequences that I'm not seeing? Thanks, ___Joe___ _________________________________________________ Joseph D'Andrea JoeDan@West21.com WEST21.com Internet services for the 21st Century http://www.west21.com/ _________________________________________________

Messages In This Thread: effects of real low TTL ???? by Joseph D''Andrea on Nov 7, 2001 at 5:57:10 pm Re: effects of real low TTL ???? by Len Conrad on Nov 7, 2001 at 6:16:55 pm Re: effects of real low TTL ???? by Men & Mice Support on Nov 7, 2001 at 10:06:42 pm