instead of loading the solr document, an index only for the last loading
time was created. This prevents that solr has to fetch from its index
while the index is created. Excessive re-loading of documents while
indexing has shown to produce deadlocks, so this should now be
prevented.
a main problem when crawling is long waiting time cuased by crawl-delay
values from robots.txt entries. that attribute is not supported by
google and interpreted by yandex and bing in different ways. In large
crawls there is always one host which blocks the whole crawl with
extreme large values. YaCy now still obeys crawl-delay but limits them
to 10 seconds.
Additionally the blocking logic when loading new robots.txt was analyzed
and a deadlock was removed. Furthermore the construction of new queue
lists was redesigned and it was ensured that always a large list of
different hosts for host-balancing is provided for the loader.
New "Media Type detection" section in the advanced crawl start page
allow to choose between :
- not loading URLs with unknown or unsupported file extension without
checking the actual Media Type (relying Content-Type header for now).
This was the old default behavior, faster, but not really accurate.
- always cross check URL file extension against the actual Media Type.
This lets properly parse URLs ending with an apparently odd file
extension, but which have actually a supported Media Type such as
text/html.
Sample URLs with misleading file extensions added as documentation in
the crawl start page.
fixes issue #244
When using the 'From Link-List of URL' as a crawl start, with lists in
the order of one or more thousands of links, the failreason_s Solr field
maximum size (32kb) was exceeded by the string representation of the URL
must-match filter when a crawl URL was rejected because not matching.
Initializing Thread names using the Thread constructor parameter is
faster as it already sets a thread name even if no customized one is
given, while an additional call to the Thread.setName() function
internally do synchronized access, eventually runs access check on the
security manager and performs a native call.
Profiling a running YaCy server revealed that the total processing time
spent on Thread.setName() for a typical p2p search was in the range of
seconds.
This ensure consistent implementation of the url host hash generation
and easier usage finding in source code.
Also added a unit test for this function.
Applied rules :
- when the FTP URL denotes a file resource, stack it as any start URL :
eventually embedded links can be followed applying the usual depth rules
- when the FTP URL denotes a directory, list files under this directory
and stack them for crawl, and repeat the process on sub folders until
crawl depth is reached
Applied strategy : when there is no restriction on domains or
sub-path(s), stack anchor links once discovered by the content scraper
instead of waiting the complete parsing of the file.
This makes it possible to handle a crawling start file with thousands of
links in a reasonable amount of time.
Performance limitation : even if the crawl start faster with a large
file, the content of the parsed file still is fully loaded in memory.
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.
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
removed preferred IPv4 in start options and added a new field IP6 in
peer seeds which will contain one or more IPv6 addresses. Now every peer
has one or more IP addresses assigned, even several IPv6 addresses are
possible. The peer-ping process must check all given and possible IP
addresses for a backping and return the one IP which was successful when
pinging the peer. The ping-ing peer must be able to recognize which of
the given IPs are available for outside access of the peer and store
this accordingly. If only one IPv6 address is available and no IPv4,
then the IPv6 is stored in the old IP field of the seed DNA.
Many methods in Seed.java are now marked as @deprecated because they had
been used for a single IP only. There is still a large construction site
left in YaCy now where all these deprecated methods must be replaced
with new method calls. The 'extra'-IPs, used by cluster assignment had
been removed since that can be replaced with IPv6 usage in p2p clusters.
All clusters must now use IPv6 if they want an intranet-routing.
the parser initialization. To make the apk parser usable, the handling
of application type links had to be modified. Now all documents which
have not a parser attached are placed to the noload-queue while all
other documents are parsed using the associated parser class. This may
have side-Effects on other parsers and the display of different file
classes (images, apps, videos).
during document parsing; instead use the same references that would also
be written into the webgraph. That should cause that the webgraph and
the citation index express the exact same semantic.
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.
with metadata retrieval from connectors directly. This should cause
better usage of the cache. Automatically increase the metadata cache if
more memory is available.
Michael Peter Christen