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 |
|---|---|
| curl/7.47.0" "www.gladstonefamily.net | 61.204.24.144 |
| ia_archiver" "charon.gladstonefamily.net | 54.173.35.129 |
| ia_archiver" "pond1.gladstonefamily.net | 54.173.35.129 |
| Mozilla/5.0 (compatible; archive.org_bot +http://archive.org/details/archive.org_bot)" "pond1.gladstonefamily.net | 207.241.231.163 |
| Mozilla/5.0 (compatible; Daum/4.1; +http://cs.daum.net/faq/15/4118.html?faqId=28966)" "blog.gladstonefamily.net | 203.133.170.164 |