Would some kind of caching crawler mitigate this issue? Have someone
write a well behaved crawler which allowed you to download a recent
.ttl.tgz of various sites. Of course, that assumes the student is able
to find such a cache.
Asking people nicely will only work in a very small community.
Henry Story wrote:
A solution to stupid crawlers would be to put the linked data behind https endpoints, and use WebID
for authentication. You could still allow everyone access, but at least you would force the crawler to identify
himself, and use these WebIDs to learn who was making the crawler. This could then be used as a piece of the evaluation of the quality of a semantic web stack.
Henry
10 minute intro to WebID http://bblfish.net/blog/2011/05/25/ (in browsers, but
the browser is not really necessary)
On 21 Jun 2011, at 09:49, Martin Hepp wrote:
Hi all:
For the third time in a few weeks, we had massive complaints from site-owners
that Semantic Web crawlers from Universities visited their sites in a way close
to a denial-of-service attack, i.e., crawling data with maximum bandwidth in a
parallelized approach.
It's clear that a single, stupidly written crawler script, run from a powerful University network, can quickly create terrible traffic load.
Many of the scripts we saw
- ignored robots.txt,
- ignored clear crawling speed limitations in robots.txt,
- did not identify themselves properly in the HTTP request header or lacked contact information therein,
- used no mechanisms at all for limiting the default crawling speed and re-crawling delays.
This irresponsible behavior can be the final reason for site-owners to say
farewell to academic/W3C-sponsored semantic technology.
So please, please - advise all of your colleagues and students to NOT write simple
crawler scripts for the billion triples challenge or whatsoever without familiarizing
themselves with the state of the art in "friendly crawling".
Best wishes
Martin Hepp
Social Web Architect
http://bblfish.net/
--
Christopher Gutteridge -- http://id.ecs.soton.ac.uk/person/1248
You should read the ECS Web Team blog: http://blogs.ecs.soton.ac.uk/webteam/
