to support the new time parser and search functions in YaCy a high
precision detection of date and time on the day is necessary. That
requires that the time zone of the document content and the time zone of
the user, doing a search, is detected. The time zone of the search
request is done automatically using the browsers time zone offset which
is delivered to the search request automatically and invisible to the
user. The time zone for the content of web pages cannot be detected
automatically and must be an attribute of crawl starts. The advanced
crawl start now provides an input field to set the time zone in minutes
as an offset number. All parsers must get a time zone offset passed, so
this required the change of the parser java api. A lot of other changes
had been made which corrects the wrong handling of dates in YaCy which
was to add a correction based on the time zone of the server. Now no
correction is added and all dates in YaCy are UTC/GMT time zone, a
normalized time zone for all peers.
parsing into individual pages and add them all using different URLs.
These constructed urls are generated from the source url with an
appended page=<pagenumber> attribute to the url get/post properties.
This will distinguish the different page entries. The search result list
will then replace the post parameter with a url anchor # mark which
causes that the original url is presented in the search result. These
URLs can be opened directly on the correct page using pdf.js which is
now built-in into firefox. That means: if you find a search hit on page
5 and click on the search result, firefox will open the pdf viewer and
shows page 5.
so viewed text and metadata (stored) info is similar
- to archive it, use request with profile to allow indexing (defaultglobaltext) and update index
(the resource is loaded, parsed anyway, so it's not a expensive operation)
Request: remove 2 unused init parameter
- number of anchors of the parent
- forkfactor sum of anchors of all ancestors
attribute in the <a> tag for each crawl. This introduces a lot of
changes because it extends the usage of the AnchorURL Object type which
now also has a different toString method that the underlying
DigestURL.toString. It is therefore not advised to use .toString at all
for urls, just just toNormalform(false) instead.
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.
jdk-based logger tend to block
at java.util.logging.Logger.log(Logger.java:476) in concurrent
environments. This makes logging a main performance issue. To overcome
this problem, this is a add-on to jdk logging to put log entries on a
concurrent message queue and log the messages one by one using a
separate process.
- FTPClient uses the concurrent logging instead of the log4j logger
id to be tested, but with a collection of ids. This will cause only a
single call to solr instead of many. The result is a much better
performace when testing the existence of many urls. The effect should
cause very much less IO during index transmission, both on sender and
receiver side.
The default schema uses only some of them and the resting search index
has now the following properties:
- webgraph size will have about 40 times as much entries as default
index
- the complete index size will increase and may be about the double size
of current amount
As testing showed, not much indexing performance is lost. The default
index will be smaller (moved fields out of it); thus searching
can be faster.
The new index will cause that some old parts in YaCy can be removed,
i.e. specialized webgraph data and the noload crawler. The new index
will make it possible to:
- search within link texts of linked but not indexed documents (about 20
times of document index in size!!)
- get a very detailed link graph
- enhance ranking using a complete link graph
To get the full access to the new index, the API to solr has now two
access points: one with attribute core=collection1 for the default
search index and core=webgraph to the new webgraph search index. This is
also avaiable for p2p operation but client access is not yet
implemented.
URIMetadataNode which creates the opportunity to access Solr objects
directly and use their information richness
- lazy initialization of the URIMetadataNode object - should cause less
computation and memory usage during search.
- removed dead code
Michael Christen