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
- when using a site operator search for a domain where the domain has a
www prefix, also the domain without the www is enclosed
- when using a site operator search for a domain where the domain has no
www prefix, also the domain with the www in enclosed
- in the host navigator, all domains with and without a www prefix are
accumulated. That means that the host navigator does never show a host
with a www prefix.
This should prevent usage mistakes of the site operator.
Michael Peter Christen