From owner-freebsd-hackers Tue Apr 10 10:33:52 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from renown.cnchost.com (renown.concentric.net [207.155.248.7]) by hub.freebsd.org (Postfix) with ESMTP id 88F8F37B424; Tue, 10 Apr 2001 10:33:49 -0700 (PDT) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (adsl-209-204-185-216.sonic.net [209.204.185.216]) by renown.cnchost.com id NAA09610; Tue, 10 Apr 2001 13:33:41 -0400 (EDT) [ConcentricHost SMTP Relay 1.10] Message-ID: <200104101733.NAA09610@renown.cnchost.com> To: Robert Watson Cc: r.hyunseog@ieee.org, hackers@freebsd.org Subject: Re: Interesting article. In-Reply-To: Your message of "Tue, 10 Apr 2001 10:54:16 EDT." Date: Tue, 10 Apr 2001 10:33:40 -0700 From: Bakul Shah Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG From the top level page I read hotmail handles 550,000 change requests a day. Later in the article they say they have a 5000 server farm. That translates to 110 change requests a day on average per server. If the peak rate is 10 times the average, that is still only about 1100 requests/server/day or about 78 seconds on average. This rate seems quite low even when you account for multiple web page servings per change request.... Am I missing something obvious? In http://www.microsoft.com/technet/migration/hotmail/hotdepl.asp they say this: With these major changes and few other minor ones, the number of requests per second that could be handled nearly doubled what the live site was experiencing. Compared to what? FreeBSD servers running perl based cgi scripts? Or converted servers running c++ based scripts? Even if the latter, a mere doubling of performance makes me think very likely they did not look at *all* the hotspots (meaning carefully look at where and how much time is spent for each request on every machine taking part, bandwidth of network and disk etc). And you have to keep looking since hotspots move as you speed things up. Though, a lack of good Unicode support on FreeBSD seems like a legitimate enough reason for the move. Regardless, note that doubling of the performance meant they saved anywhere from $10M to $20M (5000 servers x (price + maintenance of each server) - development and testing costs). Another doubling would still save them $5M or so! I'd take that challenge if I can get 50% of the savings!:-) It would be interesting to see what Yahoo has done for Yahoo mail. -- bakul To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message