not-flushed Solr cache is now handled in this way:
- it is smaller by default
- an Solr-internal process is started to flush the cache periodically
(this does NOT clean the cache, just removes old objects)
- a Solr-external process (the standard YaCy cleanup-process) now has
direct access to the solr internal cache and flushes them completely.
The time frame for such a flush is defined by the cleanup-process
frequency, by default 10 minutes.
- transformed log lines to String before they are stored because the
storage space is about 1:250 (45kb for one line before transformation,
180 bytes afterwards)
- this saves up to 10MB RAM so we can increase the number of lines to
1000 again.
the right content domain (i.e. identifying that it is an image, text
etc.) because it used the file extension and not an existing mime type
assignment.
- fixed the new setting that images shall be loaded for a better image
search.
- both fixes together makes it now possible to crawl
commons.wikimedia.org which makes use of 'funny' document names (i.e.
ending with .jpg while the document is html)
webgraph index which is temporary filled with the crawl profile key.
This is used to select a set of documents for post-processing as soon as
a crawl is finished. Now the postprocessing for a specific crawl is
started when that specific crawl is finished and not at the end of all
post-processing steps.
is visible whenever a location is available in the search result.
To activate this, the search.navigation property in yacy.conf must be
modified to the new default values.
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
fuzzy_signature_copycount_i, which count the number of copies of
non-unique documents and assigns this to each document. Thus, each
document there is a number assigned which shows how many copies of this
document exists.
These fields are disabled by default.
like normal documents. Using this option (by default on at this moment;
this might change soon) it is possible to get the exif data into the
search index to be used in image search.
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.
without the file extension. This part of the file path is removed from
the multi-field url_paths_sxt, which has now not the file name as last
part of the path list.
The same applies to the new fields source_file_name_s and
target_file_name_s in the webgraph schema.
references_internal_url_sxt because they had been shown to be
superfluous. The citation of referrer in the host browser is possible
without them. Therefore now the host browser does not only show
internal, but also external referrer to each link.
explored for citations within other documents. A click on the
'Citations' link shows an analysis with all text lines in the document
each with a complete list of documents which contain the same line. A
second section shows the linking documents in ascending order of number
of citations from the original document. Because documents from
different hosts are most interesting here, they are listed at the top of
the page as possible 'copypasta' source.
yacy will load linked web pages from search results until the total
number of web pages reaches 15000. This shall give fresh peers a 'boost'
to get faster a personalized search index.
function. This replaces the previous formula, which was bad. Before you
update to this version, please check if you changed the ranking function
yourself before, since it will be overwritten.
While the values for the reference evaluation are computed, also a
backlink-structure can be discovered and written to the index as well.
The host browser has been extended to show such backlinks to each
presented links. The host browser therefore can now show an information
where an document is linked. The new citation reference is computed as
likelyhood for a random click path with recursive usage of previously
computed likelyhood. This process is repeated until the likelyhood
converges to a specific number. This number is then normalized to a
ranking value CRn, 0<=CRn<=1. The value CRn can therefore be used to
rank popularity within intra-domain link structures.
- move setting of system property solr.directoryFactory=solr.MMapDirectoryFactory to solrcore.properties
- add check of os.arch for 64bit system, if it fails use default/solrcore.x86.properties (if exists) as solrcore.properties
reason: on 32bit MMapDirectoryFactory may fail with.....
Caused by: java.io.IOException: Map failed
at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:849)
at org.apache.lucene.store.MMapDirectory.map(MMapDirectory.java:283)
soft commits, reduced caching size of search events, ensured that solr
results are processed before connection is closed to keep that stuff not
too long in RAM
This will enable https-access to YaCy, but this feature is disabled by
default using the new server.https=false attribute. This has two
purposes:
- make it easier for everyone to use https (just set server.https=true)
- provide the basis for secure yacy-to-yacy communication in the future
holds the number of documents for the host where the document is hosted.
This is necessary for ranking and the norming of references per local
host in the ranking computation.
references_external_i and references_exthosts_i. These can be used to
count and evaluate the number of external links to every web page. An
experimental ranking function can be i.e.:
div(add(references_internal_i,product(references_external_i,references_exthosts_i)),add(clickdepth_i,1))
- no document search this time
- adjusted banner and network to not show 'WORDS' but DHT Chunks. This
is to avoid confusion for robinson peers which do not create Word
Entries
- an existing ranking servlet for solr was extended. It is now possible
to set boost values for fields, boost functions and boost queries.
- The ranking can have different instances, but currently only the first
one is used
- added an abstraction layer for fields which can be used for search and
those fields can be edited in the solr ranking configruation
- the ranking value from solr within the field score is used to combine
remote search requests, which all are created using the same locally
defined boost values
- reduced the number of fields which are used for search (makes it
faster)
- replaced some text fields by string fields (makes indexing faster)
- removed classes which had no use
- made a large number of experiments for a better ranking and created a
temporary setting which prefers hits inside titles
- adjusted also the RWI-based ranking computation to 'prefer title'
- made special cases like for portal search where no post-processing and
post-ranking is wanted: this keeps the original ranking order as done by
Solr
- fixed many bugs with old settings for ranking
- removed unused solr access classes
- made snippet generation for documents aus YaCy RWI/DHT concurrent (as
it was before the search process removation)
- reduced the number of remote results in settings file because the
processing of such mass documents add is too CPU-intensive (in Solr)
index (new solr core webgraph) .. this is now off by default
- completely redesigned this servlet
- added description how to attach a remote solr
- adjusted naming of servlet and menues
- moved 'lazy initialization' attribut from IndexSchema to
IndexFederated (this is a general option) back again.
log4j-over-slf4j is there. From slf4j all loggings are routed to the jdk
logger. Now all loggings are consistently done to the jdk logger.
- added some lines to the logging properties to suppress many solr
logging statements. The number of the logging entries had already become
a performance issue, therefore removing these from the log should
increase performance.
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.
structure, but is not filled yet. To have the opportunity of a second
core, multi-core functionality had to be implemented to the
deep-embedded solr:
- migrated the solr_40 directory content to a subdirectory
'collection1'; the previously used default core is now called
collection1
- added solr_40/webgraph subdirectory as second core
- added a servlet configuration for the second core 'webgraph' in
/IndexSchema_p.html
- added instance handling as addition to solr connections: all solr
connectors are now instances of an solr 'instance' object; this required
a complete re-design of the solr embedding
- migrated also caching and sharding ontop of new instance handling
- migrated the search apis to handle now the access to a specific core,
the default core named 'collection1'
- migrated the remote solr search interface to access shards of cores;
for the yacy remote search the default core is now called 'solr'; using
the peer address as solr address
- migrated the solr backup and restore process: old backups cannot be
used after this migration!
- redesign of solr instance handling in all methods which access the
instances: they cannot hold copies of these instances any more; the must
retrieve the actuall connection object every time they want to write to
it (this solves also some bugs when switching the index/network)
- added another schema 'solr.webgraph.schema', the old solr.keys.list is
replaced by solr.collection.schema
4.0.0 there is a new softcommit feature which implements a
near-real-time (NRT) search option. The softcommit does not do IO and
does not cause performance issues.
YaCy has now an extension in its solr connectors to use the softcommit
feature. The softcommit call now replaces all places where a hard commit
was used. Furthermore the commit strategy in when doing a search from
the web interface was changed (it's done every time before a search is
done).
The softcommit feature was implemented because it was needed for the
following changes (customer demands), which is also included in this
git commit:
- added a feature to identify all documents which have unique titles
and/or unique descriptions. These unique flags are disabled by default.
- added also a feature to set a flag when the url from a canonical tag
is equal to the document url. This is also disabled by default.
To support the new softcommit strategy, the commitWithinMs option was
set to -1 do disable automatic commit based on document insert times. If
documents are inserted permanently then also a commit would happen
permanently whenever the commitWithinMs time is reached. This would
conflict with the regular autocommit of 10 minutes and the new
softcommit strategy.
http://forum.yacy-websuche.de/viewtopic.php?p=27509#p27509
Instead, in the start script is checked if the host is a 64 host and
-Dsolr.directoryFactory=solr.MMapDirectoryFactory is set as java option
Reverted the ramBufferSizeMB setting (this was not enabled anyway)
because that may be too much memory for small peers and embedded
systems.
Activated the mergeFactor 4; this was commented out by mistake
the target of these performance settings is the reduction of IO in
general and during search in particual.
- reduced mergeFactor to 4. This will increase the IO during indexing,
but will reduce IO during search. It will also greatly reduce the number
of open files which should make it possible to have overall larger
indexes until the number of open files in an OS is reached.
- increased ramBufferSizeMB to 256mb. This will reduce the number of
commits. This change may compensate the reduction of the mergeFactor.
- disabled updateLog. This is a real-time search feature which is
available in YaCy anyway because a commit is forced if index.html is
called. The updateLog feature causes a lot of IO during indexing and
search and produced a lot of files in SEGMENTS/solr_40/data/tlog
This attribute can be used for ranking and for other purpose (demand by
customer)
The click depth is computed in two steps:
- during indexing the current fill-state of the reverse link index is
used to backtrack the current page to the root page. The length of that
backtrack is the clickdepth. But this does not discover the shortest
click depth. To get this, a second process to check again is needed
- added a process tag that can be used to do operations on the existing
index after a crawl; i.e. calculation the shortest clickpath. Added a
field to control this operation but not a method to operate on this.
- added a visualization of the clickpath length in the host browser
- fixed conflict in htroot/yacysearch.java
- removed nedres check because that causes that the remote server is not
called at all in most cases (local index has already results but we want
more)
- fixed a regex bug (a '=' too much)
- any system supporting opensearch specification can be configured
- search query is only forwarded to remote system if not enough results available on local peer
- discover function provided, checking the local Solr index for links to opensearchdescription files, to add to the config
- sample config file with some general search engines with opensearch support
- ConfigPortal: added checkbox Host Browser
- yacy.init: added search.result.show.hostbrowser as default = on (true)
- fix HostBrowser: broken link to protected WebStructurePicture for public user
introduce a copy-field for the author field to be copied to a string
field. This field is then used to generate facets. Without this field,
the facet would consist only of the words of the author names, not of
the full author string.
clicks which are necessary to get from the portal of a host to a
specific document. At this time, only the start document is flagged with
clickdepth '0', all other with '-1'. To get the actual clickdepth, a
process must use crawled information to collect the actual number of
clicks. This will be added in another/next step.
INCOMING links to the corresponding web page. This information is taken
from the reverse link index (a 'little sister' of the RWI index).
- this field can be of use to enhance the ranking because a web page
with more incoming links can be more more important than others. But
this is not true for typical link pages like menues. Therefore the
number of outgoing links is needed.
- added a new solr attribute 'bf' to solr queries which is a boost
function extension. this field can contain a formula which comuptes the
boost according to given field values. After some experiments the
following forumla is now default:
div(add(1,references_i),pow(add(1,inboundlinkscount_i),1.6))^0.4
This takes the number of references and the inbound links. Further
experiments are needed to enhance that forumula.
This uses an enhanced version of the Nutch/Solr TextProfileSignatue.
As a result, a signature of the document is written to the solr search
index. Additionally for each time when a signature is written, it is
checked if the singature exists already in the index. If the signature
does not exist, the document is marked as unique. The unique attribute
can now be used to sort document lists and bring duplicates to the end
of a result list.
To enable this, a large portion of the search api to Solr had to be
changed. This affected mainly caching of 'exists' searches to enhance
the check for existing signatures and do this without actually doing a
solr query.
Because here the first time a long number is used as value in the Solr
store, also the value naming in the YaCySchema had to be adopted and
normalized. This caused that many files had to be changed.
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
on the jaudiotagger library. The parser is disabled by default as it
needs to store temporary files for non file:// protocols, which might be
disliked. For your local MP3-collection it loads nicely Artist,
Title, Album etc. from the audio files meta data.
This can be used to add another stemming to solr using stemming files
that are expressed as synonyms for grammatical alternatives. The
synonym/stemming files must have the following form:
- each line is a comma-separated list of synonyms
- the list of synonyms may be enclosed with {} (like the GSA synonyms
file)
- the file may contain comments which are lines starting with a '#'
The synonym file(s) must be placed in DATA/DICTIONARIES/synonyms/ and
are activated by default whenever a synonym file is in place.
Then, for each word that is found in a document all synonyms are added
to a long text field which is stored into synonyms_t. Processes using
the synonyms must query with that field as optional matcher.
this new search interface is something completely new for search, but
completely common on desktops: browser a web space like one would browse
a file system in a file browser. The file listing is created using the
search index and a faceted restriction to specific domains.
create an document entry. This makes remote search much slower.
- removed synchronization of add method if ip_s is activated to prevent
that a user configuration causes bad behavior. The disadvantage of that
is, that a index dump can cause data loss if an indexing is running
during index dump
- catched more exceptions and more NPE
- better abstraction in MirrorSolrConnector
- slight performance enhancement when only the index count is requested
(rows=0 is sufficient to get a total count)
Michael Peter Christen