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.
Shutdown was hanging in CrawlQueues.close() at
this.workerQueue.put(POISON_REQUEST) when config value
crawler.MaxActiveThreads was greater than 200.
Revealed by "Collision" Threads dumps in mantis 689
(http://mantis.tokeek.de/view.php?id=689#c1312)
Fixed consistency between this.worker.length and this.workerQueue
capacity, and made the process more reliable using non-blocking offer()
function.
Even after network switch, ErroCache was still holding a reference to
the previous Solr cores, thus becoming useless until next YaCy restart.
Initial error cache filling with recent errors from the index was also
missing after the swtich.
after restart, put hosthash in queue's filename (which is used as primary
key for crawl queue. Hint: initial hosthash from url and recalculated hosthash
from just hostname:port are not the same.
fixes http://mantis.tokeek.de/view.php?id=668 (partially)
This is the 1st rudimentary approach to support the translatio utilities.
It allows currently to edit untranslated text and save it in a local translation file
in the DATA/LOCALE directory.
+ refactor Translator (less static's) to leverage on class overrides and support garbage collection for this 1 time routine
+ adjust TranslatorXliff to check for local translations in DATA/LOCALE,
this includes storing manually downloaded translation files in DATA as well
(to keep default untouched)
+ on 1st call of Translator_p a master tanslation file is generated, checking
the supported languages for missing translation text (later this masterfile is planned to part of the distribution, to harmonize translation key text between the languages)
Outlook: the local modifications (possibly as translation fragments instead of complete file) to be shared with maintainer using xlif features.
- Above brought up that parser start url parameter, declared as AnchorURL uses only methodes of parent object DigestURL (changed parameter declaration accordingly).
In rare cases hostname may not be a valid filesystem directory name,
which can't be created (e.g. containing '*' char). To prevent crawl queue
looping on this invalid entry by throwing a malformedurlexception.
and allow injection of recrawl urls before queue is empty
During recrawl the balancer hangs on the very last urls often on hosts with huge delay time,
by allowing injection earlier progress is more balanced. Max number of injected crawl urls by recrawl job is 2 * max loader.
This is a workaround for existing index (not fully reindexed) since intro of schema with docvalues
to prevent solr exception causing recrawljob to fail with
org.apache.solr.core.SolrCore java.lang.IllegalStateException: unexpected docvalues type NONE for field 'load_date_dt' (expected=NUMERIC). Use UninvertingReader or index with docvalues.
If remote crawl option is not activated, skip init of remoteCrawlJob to save the resources of queue and ideling thread.
Deploy of the remoteCrawlJob deferred on activation of the option.
added to IndexReIndexMonitor_p.html
Selects existing documents from index and feeds it to the crawler.
currently only the field fresh_date_dt is used determine documents for recrawl (fresh_date_dt:[* TO NOW-1DAY]
Documents are added in small chunks (200) to the crawler, only if no other crawl is running.
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.
- date navigation
The date is taken from the CONTENT of the documents / web pages, NOT
from a date submitted in the context of metadata (i.e. http header or
html head form). This makes it possible to search for documents in the
future, i.e. when documents contain event descriptions for future
events.
The date is written to an index field which is now enabled by default.
All documents are scanned for contained date mentions.
To visualize the dates for a specific search results, a histogram
showing the number of documents for each day is displayed. To render
these histograms the morris.js library is used. Morris.js requires also
raphael.js which is now also integrated in YaCy.
The histogram is now also displayed in the index browser by default.
To select a specific range from a search result, the following modifiers
had been introduced:
from:<date>
to:<date>
These modifiers can be used separately (i.e. only 'from' or only 'to')
to describe an open interval or combined to have a closed interval. Both
dates are inclusive. To select a specific single date only, use the
'to:' - modifier.
The histogram shows blue and green lines; the green lines denot weekend
days (saturday and sunday).
Clicking on bars in the histogram has the following reaction:
1st click: add a from:<date> modifier for the date of the bar
2nd click: add a to:<date> modifier for the date of the bar
3rd click: remove from and date modifier and set a on:<date> for the bar
When the on:<date> modifier is used, the histogram shows an unlimited
time period. This makes it possible to click again (4th click) which is
then interpreted as a 1st click again (sets a from modifier).
The display feature is NOT switched on by default; to switch it on use
the /ConfigSearchPage_p.html servlet.
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
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.
notions within the fulltext of a document. This class attempts to
identify also dates given abbreviated or with missing year or described
with names for special days, like 'Halloween'. In case that a date has
no year given, the current year and following years are considered.
This process is therefore able to identify a large set of dates to a
document, either because there are several dates given in the document
or the date is ambiguous. Four new Solr fields are used to store the
parsing result:
dates_in_content_sxt:
if date expressions can be found in the content, these dates are listed
here in order of the appearances
dates_in_content_count_i:
the number of entries in dates_in_content_sxt
date_in_content_min_dt:
if dates_in_content_sxt is filled, this contains the oldest date from
the list of available dates
#date_in_content_max_dt:
if dates_in_content_sxt is filled, this contains the youngest date from
the list of available dates, that may also be possibly in the future
These fields are deactiviated by default because the evaluation of
regular expressions to detect the date is yet too CPU intensive. Maybe
future enhancements will cause that this is switched on by default.
The purpose of these fields is the creation of calendar-like search
facets, to be implemented next.
- snapshots can now also be xml files which are extracted from the solr
index and stored as individual xml files in the snapshot directory along
the pdf and jpg images
- a transaction layer was placed above of the snapshot directory to
distinguish snapshots into 'inventory' and 'archive'. This may be used
to do transactions of index fragments using archived solr search results
between peers. This is currently unfinished, we need a protocol to move
snapshots from inventory to archive
- the SNAPSHOT directory was renamed to snapshot and contains now two
snapshot subdirectories: inventory and archive
- snapshots may now be generated by everyone, not only such peers
running on a server with xkhtml2pdf installed. The expert crawl starts
provides the option for snapshots to everyone. PDF snapshots are now
optional and the option is only shown if xkhtml2pdf is installed.
- the snapshot api now provides the request for historised xml files,
i.e. call:
http://localhost:8090/api/snapshot.xml?urlhash=Q3dQopFh1hyQ
The result of such xml files is identical with solr search results with
only one hit.
The pdf generation has been moved from the http loading process to the
solr document storage process. This may slow down the process a lot and
a different version of the process may be needed.
list of latest/oldest entries in the snapshot database. This is an
example:
http://localhost:8090/api/snapshot.rss?depth=2&order=LATESTFIRST&host=yacy.net&maxcount=100
The properties depth, order, host and maxcount can be omited. The
meaning of the fields are:
host: select only urls from this host or all, if not given
depth: select only urls at that crawl depth or all, if not given
maxcount: select at most the given number of urls or 10, if not given
order: either LATESTFIRST to select the youngest entries, OLDESTFIRST to
select the first entries or ANY to select any
The rss feed needs administration rights to work, a call to this servlet
with rss extension must attach login credentials.
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
be transcoded into jpg for image previews. To create such pdfs you must
do:
Add wkhtmltopdf and imagemagick to your OS, which you can do:
On a Mac download wkhtmltox-0.12.1_osx-cocoa-x86-64.pkg from
http://wkhtmltopdf.org/downloads.html and downloadh
ttp://cactuslab.com/imagemagick/assets/ImageMagick-6.8.9-9.pkg.zip
In Debian do "apt-get install wkhtmltopdf imagemagick"
Then check in /Settings_p.html?page=ProxyAccess: "Transparent Proxy" and
"Always Fresh" - this is used by wkhtmltopdf to fetch web pages using
the YaCy proxy. Using "Always Fresh" it is possible to get all pages
from the proxy cache.
Finally, you will see a new option when starting an expert web crawl.
You can set a maximum depth for crawling which should cause a pdf
generation. The resulting pdfs are then available in
DATA/HTCACHE/SNAPSHOTS/<host>.<port>/<depth>/<shard>/<urlhash>.<date>.pdf
set to 'Always Fresh' the cache is always used if the entry in the cache
exist. This is a good way to archive web content and access it without
going online again in case the documents exist.
To do so, open /Settings_p.html?page=ProxyAccess and check the "Always
Fresh" checkbox.
This is set do false which behave as set before.
If you set this to true, then you have your web archive in DATA/HTCACHE.
Copy this to carry around your private copy of the internet!
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.
filled with the date, when the url is recognized as to be outdated. That
field was partly misinterpreted and the time interval was filled in. In
case that all the urls which are in the index shall be treated as
outdated, the field is filled now with Long.MAX_VALUE because then all
crawl dates are before that date and therefore outdated.
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.
crawling to the YaCy indexer. Files are uploaded using POST multipart
requests; multiple file uploads are possible as well. Each file has
attached the file date and mime type which is used to get the right
parser for the submitted data. Also an url is submitted which is
assigned to the document.
The CrawlSwitchboard has a new option for default Crawl Profiles which
are assigned dynamically from the new push interface.
use alternative delete to fight the sympthom (and fix deletion of host dirs on startup)
Root cause (which class holds a lock on .stack) not found.
http://mantis.tokeek.de/view.php?id=404
local files can be crawled (intranet mode) url parsing fixed according to RFC 1738 (for unix and windows)
for win like file:///c:/tmp or file://localhost/c:/tmp
for linux like file:///tmp or file://localhost/tmp
Host is ignored and path must be absolute
- 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.
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.
processes in favor of throwaway-processes. The control mechanism does
less often report a 'queue full' message to the busy loop which then
does not perform a long busy waiting; instead all requests are queued
and new loader processes are started if necessary up to a given limit
(as set before)
instead of TreeMaps)
- enhanced memory footprint of database indexes (by introduction of
optimize calls)
- optimize calls shrink the amount of used memory for index sets if they
are not changed afterwards any more
luccioman
