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.
- migrates all entries in old urldb
Metadata coordinate (lat / lon) NumberFormatException still relative often (see excerpt below),
- added try/catch for URIMetadataRow (seems not to be needed in URIMetaDataNode, as Solr internally checks for number format)
- removed possible typ conversion for lat() / lon() comparison with 0.0f, changed to 0.0 (leaving it to the compiler/optimizer to choose number format)
current log excerpt for NumberFormatException:
W 2013/01/14 00:10:07 StackTrace For input string: "-"
java.lang.NumberFormatException: For input string: "-"
at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
at java.lang.Double.parseDouble(Unknown Source)
at net.yacy.kelondro.data.meta.URIMetadataRow$Components.lon(URIMetadataRow.java:525)
at net.yacy.kelondro.data.meta.URIMetadataRow.lon(URIMetadataRow.java:279)
at net.yacy.search.index.SolrConfiguration.metadata2solr(SolrConfiguration.java:277)
at net.yacy.search.index.Fulltext.putMetadata(Fulltext.java:329)
at transferURL.respond(transferURL.java:152)
...
Caused by: java.lang.NumberFormatException: For input string: "-"
at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
at java.lang.Double.parseDouble(Unknown Source)
at net.yacy.kelondro.data.meta.URIMetadataRow$Components.lon(URIMetadataRow.java:525)
at net.yacy.kelondro.data.meta.URIMetadataRow.lon(URIMetadataRow.java:279)
at net.yacy.search.index.SolrConfiguration.metadata2solr(SolrConfiguration.java:277)
at net.yacy.search.index.Fulltext.putMetadata(Fulltext.java:329)
at transferURL.respond(transferURL.java:152)
metadata and old rwi and for the citation index. The important
advancement is the separation of the citation index deletion because
that index is responsible for the linkdepth calculation. Now a search
index can be deleted without the citation index and that should cause
that less clickdepths must be post-processed.
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
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.
the actual data which is fetched from solr.
- used the new field options to reduce generic options like getting the
load date or the count of search results. should increase overall speed
- used the new field options to reduce overhead in the host browser
during aquisition of links.
- used the field options to make checking of links in crawler faster
- if the crawler is paused, the crawl queue is not cleaned
added solr highlighting / YaCy snippets to YaCy search results
- facets are now much more complete
- facets are computed and searched much faster
- snippet computation is done by solr if solr knows the snippet
- only visible for admins
- a faceted search generates a huge list for all hosts in the host list
- the faceted search algorithms had to be modified for that
- within the browsing of the directory path, the error cause is written
to the url which is presented as error-url
- the errors are also accumulated for directory sums
deleted which are selected by a crawl filter (host or subpath)
- site crawl used this option be default now
- made option to deleteDomain() concurrency
- time-out after 3 seconds to speed up display (may be incomplete)
- showing also all links from the balancer queue in the host list (after
the '/') and in the result browser view with tag 'loading'
superfluous. The target is to make a solr document as the core of YaCy
documents which would cause that many conversions can be removed. On the
way to this target the Equivalence of URIMetadataRow and URIMetadataNode
had to be removed to expose the usage of the old URIMetadataRow data
structure.
This refactoring already removes unneccessary conversions and should
make memory usage during indexing lower.
which had been then mixed with remote RWIs. Now these Solr documents are
feeded into the result set as they appear during local and remote
search. That makes the search much faster.
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
- showing also outbound links to other domains if there are any
- the outbound links browser shows also the link structure image
- showing even inbound links if the web structure graph has information
about that
- removed the left menu and made the HostBrowser a part of the top menu
for search
- moved the file search also to the top menu
- added hover information in the HostBrowser to explain what the click
means
- because the HostBrowser also links to the Metadata viewer ViewFile,
there should be a button to switch back to the HostBrowser: added that
also.
MultiProtocolURI during normalform computation because that should
always be done and also be done during initialization of the
MultiProtocolURI Object. The new normalform method takes only one
argument which should be 'true' unless you know exactly what you are
doing.
there is no need for the RWI index if the index is not transfered to
another peer. Therefore the creation of RWI index data is now suppressed
if DHT is disabled. This applies for all intranet and portal mode
configurations, but not for public robinson modes. A robinson may switch
back to public mode and then transmit its data. That means if someone
wants to switch never to DHT mode, it would be more appropriate to
choose the portal mode.
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.
Therefore a property like solrConnected() must be true all the time.
Removal of this method causes removal of all write operations to the old
metadata index.
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)
dump commands
- adjusted the apicall.sh script to get the downloaded text as output to
stdout which is necessary to parse the content out of it
- added indexdump.sh script which creates a solr dump and prints out the
storage path for the index dump
- added synchronization to the Fulltext class to prevent that data is
stored to a non-existing solr index while this index is disabled during
the storage of the dump
- 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)
- reduced danger that a non-existing RWI database causes NPEs
- added Solr queries to did-you-mean: this makes it possible that our
did-you-mean algorithm works together with only Solr and without RWIs
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
Node to Row objects
- removed peerDeparture in solr remote search in case that peer does not
answer (this may be normal because it is allowed to switch this off)
solr as fulltext search index.
- added slow migration from old metadata to solr index entries: each
entry from the old metadata is removed from that data structure and
written into solr.
to have a fall-back option in case that memory problems as reported in
http://forum.yacy-websuche.de/viewtopic.php?p=26901#p26901
for full-solr installation are too strong and we have to work with an
'small memory footprint' peer system.
attached, the metadata is not written to the metadata-db, even if it is
enabled but instead to solr. This prevents that metadata is written in
two store systems at the same time. It is also the next step to migrate
the current metadata-db to solr.
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
or will be superfluous or subject of complete redesign after the
migration to solr. Removing these things now will make the transition to
solr more simple.
- by default, a (empty) solr storage instance is created at
SEGMENTS/solr_36
- the index is written if in /IndexFederated_p.html the flag "embedded
solr search index" is switched on
- a standard solr query interface is available now with a new servlet at
http://127.0.0.1:8090/solr/select
To test this, do the following:
- switch to webportal mode
- switch on the feature as described
- do a crawl. this fills the solr index. The normal YaCy search will NOT
work now!
- do a solr query, like:
http://127.0.0.1:8090/solr/select?q=*:*
http://127.0.0.1:8090/solr/select?q=text_t:Help
play with different search fields as you can see in
/IndexFederated_p.html
You can use the standard solr query attributes as described in
http://wiki.apache.org/solr/SearchHandler
the segments had been there to create a tenant-infrastructure but were
never be used since that was all much too complex. There will be a
replacement using a solr navigation using a segment field in the search
index.
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
- added log warnings in case that search processes run into time-out
situations
- better concurrency for Integer formatter (used a non-synchronized
formatter before)
- bugfix for search termination (a poison pill was missing)
- added timeout parameters for search (again) -> target is, that they
are never reached.
- search request are now made using a map boundary
- search results are only computed for the map boundary
- the number of results is adopted to the results in the visible range
- added a double-buffering for the search result markers
- added a search query option for the search results:
/radius/<lat>/<lon>/<radius>
- Changing the format of YaCy's solr.key.list while maintainig backward compatibility
Federated index config screens adjusted accordingly
- modified the Solr update request to use a 3 min Solr autocommit intervall
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
- a new database for url reference data ('seen links')
- a new database extending the references to the full url metadata
attributes set which shall replace the old metadata database if it is
finished
- migration help classes stub to use old and new metadata databases
simultanously
the links between all pages are now stored. The same index structure as
used for the word index is used to make a reverse link index.
The new file(s) in SEGMENT/default/citation.index.*.blob store the
citation index. This will be used to create much more detailed link
structures for the YaCy apis and to create a better ranking. A ranking
using the citation.index should provide better results especially for
portal indexes and initranets.
Michael Peter Christen