Adding compression support can be very simple -- if your spider is coded in Perl using LWP::UserAgent, then the
addition of a single line of code will enable compression support.
$ua->default_header('Accept-Encoding' => 'gzip');
and then you need to make sure that you always refer to 'decoded_content' when dealing with the response object.
For other languages, all
you need to do is to add
Accept-encoding: gzipto the HTTP request that you send, and then be prepared to deal with a 'content-encoding: gzip' in the response.
Happily, some of the large spiders do support compression -- the googlebot and Yahoo Slurp do (to name but two). Since I started prodding crawler implementors, a couple have implemented compression (one within hours), and another reported that it was a bug that it didn't work -- which would be fixed shortly.
Crawlers which do more than 5% of the total (uncompressed) crawling activity are marked in bold below.
| Crawler | Last IP used |
|---|---|
| LightspeedSystemsCrawler Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)" "gladstonefamily.net | 207.200.8.182 |
| masscan/1.0 (https://github.com/robertdavidgraham/masscan)" "- | 104.152.52.21 |
| Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0)" "73.253.74.102 | 43.229.153.78 |
| Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "pond.gladstonefamily.net | 216.244.66.194 |
| Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "pond1.gladstonefamily.net | 216.244.66.194 |
| Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:31.0) Gecko/20100101 Firefox/31.0" "73.253.74.102 | 43.229.153.78 |
| Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6" "pond1.gladstonefamily.net | 95.217.155.33 |
| Wget/1.19.4 (linux-gnu)" "gladstonefamily.net | 165.227.113.144 |