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.
jdk-based logger tend to block
at java.util.logging.Logger.log(Logger.java:476) in concurrent
environments. This makes logging a main performance issue. To overcome
this problem, this is a add-on to jdk logging to put log entries on a
concurrent message queue and log the messages one by one using a
separate process.
- FTPClient uses the concurrent logging instead of the log4j logger
adjusted to smaller and 1-core devices.
- the workflow processor now starts no process at all. these are started
as soon as parser/condenser/indexing queues are filled.
- better abstraction
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.
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
multiple solr cores instead of just one. Therefore it is now necessary
to distuingish between solr server connections (called an 'Instance')
and a connection to a single solr core. One Instance may now have
multiple connector classes assigned to it, each connecting to a single
core.
To support multiple cores it is also necessary to distinguish between
the connection configuration and the configuration of the index schema.
We will have multiple schema configurations in the future, each for
every solr core. This caused that the IndexFederated servlet had to be
split into two parts, the new Servlet for the Schema editor is now in
the IndexSchema Servlet.
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.
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.
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.
- 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)
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
- 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.
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
Michael Peter Christen