Previously, when checking for the first time the robots.txt policy on a
unknown host (not cached in the robots table), result was always empty
in the /getpageinfo_p.xml api and in the /CrawlCheck_p.html page. Next
calls returned however the correct information.
When starting a crawl from a file containing thousands of links,
configuration setting "crawler.MaxActiveThreads" is effective to prevent
saturating the system with too many outgoing HTTP connections threads
launched by the crawler.
But robots.txt was not affected by this setting and was indefinitely
increasing the number of concurrently loading threads until most ot the
connections timed out.
To improve performance control, added a pool of threads for Robots.txt,
consistently used in its ensureExist() and massCrawlCheck() methods.
The Robots.txt threads pool max size can now be configured in the
/PerformanceQueus_p.html page, or with the new
"robots.txt.MaxActiveThreads" setting, initialized with the same default
value as the crawler.
- doublecheck cache now records the crawl depth as well
- doublecheck cache is available from the outside (made static)
- no more need to crawl hosts with lowest depth first, instead all hosts
which have only singleton entries are preferred to reduce the number of
files.
all unique links! This made it necessary, that a large portion of the
parser and link processing classes must be adopted to carry a different
type of link collection which carry a property attribute which are
attached to web anchors.
- introduction of a new URL class, AnchorURL
- the other url classes, DigestURI and MultiProtocolURI had been renamed
and refactored to fit into a new document package schema, document.id
- cleanup of net.yacy.cora.document package and refactoring
in intranets and the internet can now choose to appear as Googlebot.
This is an essential necessity to be able to compete in the field of
commercial search appliances, since most web pages are these days
optimized only for Google and no other search platform any more. All
commercial search engine providers have a built-in fake-Google User
Agent to be able to get the same search index as Google can do. Without
the resistance against obeying to robots.txt in this case, no
competition is possible any more. YaCy will always obey the robots.txt
when it is used for crawling the web in a peer-to-peer network, but to
establish a Search Appliance (like a Google Search Appliance, GSA) it is
necessary to be able to behave exactly like a Google crawler.
With this change, you will be able to switch the user agent when portal
or intranet mode is selected on per-crawl-start basis. Every crawl start
can have a different user agent.
MultiProtocolURI during normalform computation because that should
always be done and also be done during initialization of the
MultiProtocolURI Object. The new normalform method takes only one
argument which should be 'true' unless you know exactly what you are
doing.
luccioman