Hi,
I'm trying to gather information on how mlt works or is supposed to work
with SolrCloud and a sharded collection. I've read issues SOLR-6248,
SOLR-5480 and SOLR-4414, and docs at
<https://wiki.apache.org/solr/MoreLikeThis>, but I'm still struggling
with multiple issues. I've been testing with Solr 5.1 and the "Getting
Started" sample cloud. So, with a freshly extracted Solr, these are the
steps I've done:
bin/solr start -e cloud -noprompt
bin/post -c gettingstarted docs/
bin/post -c gettingstarted example/exampledocs/books.json
After this I've tried different variations of queries with limited success:
<http://localhost:8983/solr/gettingstarted/select?q={!mlt}non-existing>
causes java.lang.NullPointerException at
org.apache.solr.search.mlt.CloudMLTQParser.parse(CloudMLTQParser.java:80)
<http://localhost:8983/solr/gettingstarted/select?q={!mlt}978-0641723445>
causes java.lang.NullPointerException at
org.apache.solr.search.mlt.CloudMLTQParser.parse(CloudMLTQParser.java:84)
<http://localhost:8983/solr/gettingstarted/select?q={!mlt%20qf=title}978-0641723445>
causes java.lang.NullPointerException at
org.apache.lucene.queries.mlt.MoreLikeThis.retrieveTerms(MoreLikeThis.java:759)
<http://localhost:8983/solr/gettingstarted/select?q={!mlt%20qf=cat}978-0641723445>
actually gives results
<http://localhost:8983/solr/gettingstarted/select?q={!mlt%20qf=author,cat}978-0641723445>
again causes Java.lang.NullPointerException at
org.apache.lucene.queries.mlt.MoreLikeThis.retrieveTerms(MoreLikeThis.java:759)
I guess the actual question is, how am I supposed to use the handler to
replicate behavior of non-distributed mlt that was formerly used with
qt=morelikethis and the following configuration in solrconfig.xml:
<requestHandler name="morelikethis" class="solr.MoreLikeThisHandler">
<lst name="defaults">
<str
name="mlt.fl">title,title_short,callnumber-label,topic,language,author,publishDate</str>
<str name="mlt.qf">
title^75
title_short^100
callnumber-label^400
topic^300
language^30
author^75
publishDate
</str>
<int name="mlt.mintf">1</int>
<int name="mlt.mindf">1</int>
<str name="mlt.boost">true</str>
<int name="mlt.count">5</int>
<int name="rows">5</int>
</lst>
</requestHandler>
Real-life full schema and config can be found at
<https://github.com/NatLibFi/NDL-VuFind-Solr/tree/master/vufind/biblio/conf>.
--Ere
--
Ere Maijala
Kansalliskirjasto / The National Library of Finland
