- From: Andy Kumeda <kumeda@intelenet.net>
- Date: Fri, 30 Jun 1995 14:18:06 -0700 (PDT)
- To: brian@organic.com (Brian Behlendorf)
- Cc: andy@intelenet.net, Bernhard.Schneck@physik.tu-muenchen.de, www-proxy@www10.w3.org
Brian Behlendorf wrote: # # On Fri, 30 Jun 1995, Andy Kumeda wrote: # > The key here is that each server needs to be it's own primary server. # > Therefore, if the server is down, no DNS info can be given out, thus # > queries will be sent to the server that is up. # # I respectfully suggest this is very network-unfriendly. The amount of # "downtime" is directly related to the length of the DNS cache timeouts, # which means they will probably be set incredibly low - 2 minutes? 10 # minutes? It means the servers will be doing much more DNS work than # usual. I also find it hard to see how this could handle load-balancing # adequately, since it looks like DNS lookups are going to return (in your # case) 129.253.16.1 a lot more frequently than 204.182.160.150, since the # former is listed as primary for the domain wdc.com. Could you compare the # WDC-based traffic loads between the two? # # I would say this is the best try yet at trying to make redundancy # transparant in DNS... but I still think simply having the client test # latencies of each server would be the most elegant solution. Brian, I appreciate your comments, and I will attempt to clarify a few things below. Yes, the cache timeouts are set extremely low -- I don't recall what it is set at exactly off the top of my head. Also, you are right in that it does not do 'load-balancing' in the traditional sense, in fact, as you stated, it goes to the 129.253 system more frequently, and was intended to do just that. We wanted to distinguish a 'primary' and a 'secondary' (mirror) server mainly for administrative purposes, such as updating HTML files. (FWIW, the 'secondary' server currently gets appx 20% of the total hits, and I suspect that this is mainly due to DNS timeouts to the 'primary' server who happens to be on a more congested network than the 'secondary'.) I also like the idea that it should be a client feature, but until ALL clients support this, the only way it can be done is on the server end. Thus, this is the reason why I had implemented the solution above. Believe me, I'll be the first one to get rid of this implementation if there were an alternative solution, but at this time, I see no other. # # Brian # # --=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-- # brian@organic.com brian@hyperreal.com http://www.[hyperreal,organic].com/ # # Regards. -- Andy Kumeda -- Consultant Voice: 714.449.8327 InteleNet Communications, Inc. E-mail: andy@intelenet.net 30 Executive Park, Suite 265 P-mail: andy.pager@intelenet.net Irvine, CA 92714-6741 URL: http://www.intelenet.net
Received on Friday, 30 June 1995 17:15:20 UTC