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.
given css class and extends a given vocabulary with a term consisting
with the text content of the html class tag. Additionally, the term is
included into the semantic facet of the document. This allows the
creation of faceted search to documents without the pre-creation of
vocabularies; instead, the vocabulary is created on-the-fly, possibly
for use in other crawls. If any of the term scraping for a specific
vocabulary is successful on a document, this vocabulary is excluded for
auto-annotation on the page.
To use this feature, do the following:
- create a vocabulary on /Vocabulary_p.html (if not existent)
- in /CrawlStartExpert.html you will now see the vocabularies as column
in a table. The second column provides text fields where you can name
the class of html entities where the literal of the corresponding
vocabulary shall be scraped out
- when doing a search, you will see the content of the scraped fields in
a navigation facet for the given vocabulary
This organizes all urls to be loaded in separate queues for each host.
Each host separates the crawl depth into it's own queue. The primary
rule for urls taken from any queue is, that the crawl depth is minimal.
This produces a crawl depth which is identical to the clickdepth.
Furthermorem the crawl is able to create a much better balancing over
all hosts which is fair to all hosts that are in the queue.
This process will create a very large number of files for wide crawls in
the QUEUES folder: for each host a directory, for each crawl depth a
file inside the directory. A crawl with maxdepth = 4 will be able to
create 10.000s of files. To be able to use that many file readers, it
was necessary to implement a new index data structure which opens the
file only if an access is wanted (OnDemandOpenFileIndex). The usage of
such on-demand file reader shall prevent that the number of file
pointers is over the system limit, which is usually about 10.000 open
files. Some parts of YaCy had to be adopted to handle the crawl depth
number correctly. The logging and the IndexCreateQueues servlet had to
be adopted to show the crawl queues differently, because the host name
is attached to the port on the host to differentiate between http,
https, and ftp services.
for anchor attributes.
- this caused that large portions of the parser code had to be adopted
as well
- added a counter target_order_i for anchor links in webgraph
computation
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
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
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.
later
- added abstract add, delete, get methods in the triplestore
- added generation of triples after auto-annotation
- migrated all MultiProtocolURI objects to DigestURI in the parser since
the url hash is needed as subject value in the triples in the triple
store
queue and not from virtual documents generated by the parser.
- The parser now generates nice description texts for NOLOAD entries
which shall make it possible to find media content using the search
index and not using the media prefetch algorithm during search (which
was costly)
- Removed the media-search prefetch process from image search
- added a memory limitation in the zip parser and the pdf parser
- added a search throttling: if there are too many search queries are still to be computed, then new requests are not accepted for some time. if after a one second still no space is there to perform another search, the search terminates with no results. this case should only happen in case of DoS-like situations and in case of strong load on a peer like if it is integrated in metager.
- added a search cache deletion process that removes search requests in case that throttling happens
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@7766 6c8d7289-2bf4-0310-a012-ef5d649a1542
some file types are containers for several files. These containers had been parsed in such a way that the set of resulting parsed content was merged into one single document before parsing. Using this parser infrastructure it is not possible to parse document containers that contain individual files. An example is a rss file where the rss messages can be treated as individual documents with their own url reference. Another example is a surrogate file which was treated with a special operation outside of the parser infrastructure.
This commit introduces a redesigned parser interface and a new abstract parser implementation. The new parser interface has now only one entry point and returns always a set of parsed documents. In case of single documents the parser method returns a set of one documents.
To be compliant with the new interface, the zip and tar parser had been also completely redesigned. All parsers are now much more simple and cleaner in its structure. The switchboard operations had been extended to operate with sets of parsed files, not single parsed files.
additionally, parsing of jar manifest files had been added.
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6955 6c8d7289-2bf4-0310-a012-ef5d649a1542
- cleaned uo the code. The new eclipse helios provided new warnings for dead code. This change cleans up most of these warnings
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6945 6c8d7289-2bf4-0310-a012-ef5d649a1542
- it is now possible to crawl the local file system with an intranet peer
- redesign of URL handling
- refactoring: created LGPLed package cora: 'content retrieval api' which may be used externally by other applications without yacy core elements because it has no dependencies to other parts of yacy
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6902 6c8d7289-2bf4-0310-a012-ef5d649a1542
- fixes to http file server session handling
- fixes and enhancements to metadata date/time handling
- added dc:publisher metadata field and updated all document parser
- fixed bug in metdata read procedure
- enhanced dublin core and rss parser to understand more fields more properly
- enhanced url selection in case that multiple urls are given in surrogates
- fix for condenser; failure when last word does not end with termination symbol
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6863 6c8d7289-2bf4-0310-a012-ef5d649a1542
reger