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)
- a solr field collection_sxt can be used to store a set of crawl tags
- when this field is activated, a crawl tag can be assigned when crawls
are started
- the content of the collection field can be comma-separated, all of
them are assigned to the documents when they are indexed as result of
such a crawl start
- a search result can be drilled down to a specific collection; this is
currently only available in the solr interface and also in the gsa
interface using the 'site' option
- this adds a mandatory field for gsa queries (the google api demands
that field all the time)
title_count_i, title_chars_val, title_words_val
description_count_i, description_chars_val, description_words_val
- added many asserts to ensure data type correctness from YaCy to Solr
and vice versa
- made many fixes according to new findings from these asserts (!)
- fixed type definition found by the verifier
- added multivalue-string fields for solr with extension 'sxt'
- added multivalue-integer fields for solr with extension 'val'
- renamed some solr attributes from txt to sxt
- changed solr query line to an explicit AND/OR structure
- added a country code second level domain list to Domains class; with
parser
- added a host string parser to get domain class name, country-code
second-level domain and subdomain out of it
- removed old coordinate attributes
for production as a replacement of the metadata-db.
This intermediate release 1.041 will switch on the previously optional
solr index and the old metadata-db will still work as it did before.
Solr+metadata are accessed in mixed mode, no migration is done yet.
If this causes not a catastrophe until the end of the weekend, we will
do a YaCy 1.1 main release containing this as default.
metadata representation from the solr index. This shall replace metadata
from the built-in database in the future.
- added the Solr-driven metadata into the search index of YaCy which
makes it now possible to run YaCy without the old metadata index. This
is a major stept forward to a full migration to Solr.
writings to the Metadata-DB are now also done to solr. This includes
metadata transfer during search and rwi transfer.
The new/added solr fields are:
## time when resource was loaded
load_date_dt
## date until resource shall be considered as fresh
fresh_date_dt
## id of the host, a 6-byte hash that is part of the document id
host_id_s
## ids of referrer to this document
referrer_id_ss
## the md5 of the raw source
md5_s
## the name of the publisher of the document
publisher_t
## the language used in the document; starts with primary language
language_ss
## an external ranking value
ranking_i
## the size of the raw source
size_i
## number of links to audio resources
audiolinkscount_i
## number of links to video resources
videolinkscount_i
## number of links to application resources
applinkscount_i
0-values and no empty strings are written). This may save a lot of
memory (in ram and on disc) if excessive 0-values or empty strings
appear)
- do not allow default boolean values for checkboxes because that does
not make sense: browsers may omit the checkbox attribute name if the box
is not checked. A default value 'true' would not comply with the
semantic of the browsers response.
- add a checkbox in IndexFederated_p for the lazy initialization of solr
fields.
- new limit to use the table copy (instead of flag): 400MB available. If
less is available, then a copy is never used. If more is available, then
it can be used if there is a remaining space of at least 200MB
- flush caches more often: flush the Digest cache
Michael Peter Christen