Joe Michaud - 27 June 2008 12:51 PM
For those of you watching this thread who are a little more knowledgeable, I’d be interested in knowing more about the advantages & disadvantages of using DNS vs redirects.
i actually don’t know how the DNS stuff works, but i suspect it could be a bit faster that the redirects.
The redirects actually require a second request/response round trip from your browser to the web server.
You can simulate this via cmd line with a HTTP request to craigslist:
/——-
telnet craigslist.org 80
GET / HTTP/1.0
Host: craigslist.org
——-/
The response you get:
/——-
HTTP/1.1 302 Found
Content-Type: text/html; charset=iso-8859-1
Connection: close
Location: http://www.craigslist.org/
Date: Sat, 28 Jun 2008 09:17:59 GMT
Server: Apache/1.3.37 (Unix) mod_gzip/1.3.26.1a mod_perl/1.29
<!DOCTYPE HTML PUBLIC “-//IETF//DTD HTML 2.0//EN”>
<HTML><HEAD>
<TITLE>302 Found</TITLE>
</HEAD><BODY>
<H1>Found</H1>
The document has moved <A >here</A>.<P>
<HR>
<A>Apache/1.3.37 Server at sfbay.craigslist.org Port 80</ADDRESS>
</BODY></HTML>
——-/
When your browser sees that ‘Location’ header, it doesn’t even both to render the HTML page data below—it just immediately makes a brand new request for whatever URL is there - in this case, it’s using the ‘www’ version. So, it happens very quickly and invisibly to the user, but I suppose it could be meaningful if you want uber-fast performance.
I suspect a DNS-based solution would not require this 2nd round trip request. Instead, the web server would just recognize what content you were asking for and serve the appropriate content. Of course, in the previous case, the URL in the browser changes to the ‘www’ version, whereas this DNS solution would not (assuming my guess is correct about how it works).
