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; archive.org_bot +http://archive.org/details/archive.org_bot)" "pond1.gladstonefamily.net | 207.241.231.163 |
| Mozilla/5.0 (compatible; Dataprovider.com)" "blog.gladstonefamily.net | 158.69.225.36 |
| Mozilla/5.0 (compatible; Dataprovider.com)" "blog1.gladstonefamily.net | 167.114.174.95 |
| Mozilla/5.0 (compatible; Dataprovider.com)" "pond1.gladstonefamily.net | 167.114.65.240 |
| 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)" "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; oBot/2.3.1; +http://filterdb.iss.net/crawler/)" "gladstonefamily.net:8080 | 206.253.226.8 |
| Wget/1.19.4 (linux-gnu)" "pond1.gladstonefamily.net | 130.225.26.33 |