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 |
|---|---|
| Mozilla/5.0 (compatible; Daum/4.1; +http://cs.daum.net/faq/15/4118.html?faqId=28966)" "blog.gladstonefamily.net | 203.133.168.171 |
| Mozilla/5.0 (compatible; Daum/4.1; +http://cs.daum.net/faq/15/4118.html?faqId=28966)" "www.gladstonefamily.net | 203.133.168.171 |
| Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "blog1.gladstonefamily.net | 216.244.66.194 |
| Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "charon.gladstonefamily.net | 216.244.66.194 |
| Mozilla/5.0 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "gladstone.name | 216.244.66.228 |
| 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 (compatible; DotBot/1.1; http://www.opensiteexplorer.org/dotbot, help@moz.com)" "www.gladstone.name | 216.244.66.228 |
| Mozilla/5.0 (compatible; SemrushBot/1.0~bm; +http://www.semrush.com/bot.html)" "gladstonefamily.net | 85.208.96.66 |
| Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36" "pond.gladstonefamily.net | 192.99.15.139 |
| Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:28.0) Gecko/20100101 Firefox/28.0" "73.253.74.102 | 103.85.84.124 |
| Mozilla/5.0 (X11; Linux x86_64; rv:109)" "blog1.gladstonefamily.net | 69.162.89.188 |