|February 19th, 2014|
www.theguardian.comand wrote up their experiences. Among them:
At this point, however, all the URLs on the site still pointed to
www.guardian.co.uk. We attempted to fix this by implementing relative URLs across our site, but a lengthy investigation proved that this would be more difficult than it should have been. Instead, we wrote a filter which detected the HTTP
Hostheader. If the host was
www.theguardian.com, we would rewrite all the URLs on the site to be
www.theguardian.com. If the
www.guardian.co.ukwe would rewrite all the URLs on the site to be
www.guardian.co.uk. This was a simple configuration change that swapped one domain for another, per request.
Wait, they're using absolute urls instead of relative? Isn't that
http://www.theguardian.com for every
single link? That's 295 times:
$ curl -s http://www.theguardian.com/us | sed 's~http:~^http:~g' \ | tr '^' '\n' | grep -c http://www.theguardian.com/ 295
But how much bigger is this making their site, after all?
$ curl -s http://www.theguardian.com/us | wc -c 222491 $ curl -s http://www.theguardian.com/us \ | sed s'~http://www.theguardian.com~~' | wc -c 214795 $ python -c 'print 222491-214795' 7696 $ python -c 'print "%.2f%%" % (7696.0 / 214795 * 100)' 3.58%So they're using an extra 7.7kB and making their site 3.6% bigger, right? Except almost everyone will be downloading the site with gzip enabled:
$ curl -s http://www.theguardian.com/us | wc -c 222491 $ curl -s -H 'Accept-Encoding: gzip' \ http://www.theguardian.com/us | wc -c 33576In other words, if you request the page simply it's 222k but if your browser sends
Accept-Encoding: gzipwith the request, and any browser you're likely to use does this, then it's only 34k. This is equivalent to downloading the page and then gzipping it ourselves:
$ curl -s http://www.theguardian.com/us | gzip | wc -c 33576
Now gzip compression does well with simple repeated strings, so how
well does it handle these absolute urls? Let's repeat the test from
above, this time encoding with
gzip before counting bytes:
$ curl -s http://www.theguardian.com/us | gzip | wc -c 33576 $ curl -s http://www.theguardian.com/us \ | sed s'~http://www.theguardian.com~~' | gzip | wc -c 33805 $ python -c 'print 33576-33347' 229 $ python -c 'print "%.2f%%" % (229.0 / 33347 * 100)' 0.69%So yes, they could save some bytes by switching to relative urls, but the savings are under 1%.