The ngroups returns the number of groups that have matched with the query. However if you want ngroups to be correct in a distributed environment you need to put document belonging to the same group into the same shard. Groups can't cross shard boundaries. I guess you need to do some manual document partitioning.
Martijn On 11 June 2012 14:29, Nitesh Nandy <niteshna...@gmail.com> wrote: > Version: Solr 4.0 (svn build 30th may, 2012) with Solr Cloud (2 slices and > 2 shards) > > The setup was done as per the wiki: http://wiki.apache.org/solr/SolrCloud > > We are doing distributed search. While querying, we use field collapsing > with "ngroups" set as true as we need the number of search results. > > However, there is a difference in the number of "result list" returned and > the "ngroups" value returned. > > Ex: > http://localhost:8983/solr/select?q=message:blah%20AND%20userid:3&&group=true&group.field=id&group.ngroups=true > > > The response XMl looks like > > <response> > <script/> > <lst name="responseHeader"> > <int name="status">0</int> > <int name="QTime">46</int> > <lst name="params"> > <str name="group.field">id</str> > <str name="group.ngroups">true</str> > <str name="group">true</str> > <str name="q">messagebody:monit AND usergroupid:3</str> > </lst> > </lst> > <lst name="grouped"> > <lst name="id"> > <int name="matches">10</int> > <int name="ngroups">9</int> > <arr name="groups"> > <lst> > <str name="groupValue">320043</str> > <result name="doclist" numFound="1" start="0"> > <doc>...</doc> > </result> > </lst> > <lst> > <str name="groupValue">398807</str> > <result name="doclist" numFound="5" start="0" maxScore="2.4154348">... > </result> > </lst> > <lst> > <str name="groupValue">346878</str> > <result name="doclist" numFound="2" start="0">...</result> > </lst> > <lst> > <str name="groupValue">346880</str> > <result name="doclist" numFound="2" start="0">...</result> > </lst> > </arr> > </lst> > </lst> > </response> > > So you can see that the ngroups value returned is 9 and the actual number > of groups returned is 4 > > Why do we have this discrepancy in the ngroups, matches and actual number > of groups. Is this an open issue ? > > Any kind of help is appreciated. > > -- > Regards, > > Nitesh Nandy -- Met vriendelijke groet, Martijn van Groningen
