Solr 4 - Missing Field Collapsing Components

Question

according to the Solr Wiki (http://wiki.apache.org/solr/FieldCollapsing) field collapsing should be available in Solr 4. As far as I know, it is necessary to add the following configuration to the solrconfig.xml to activate field collapsing:

<searchComponent name="query"
     class="org.apache.solr.handler.component.CollapseComponent" />

I downloaded the latest nightly build apache-solr-4.0-2011-10-26_08-46-59.zip from https://builds.apache.org/job/Solr-trunk/, updated my project from lucidworks solr 3.2 to apache solr 4.x and finally found out, that the class org.apache.solr.handler.component.CollapseComponent is not available inside the apache-solr-core-4.0-2011-10-26_08-46-59.jar.

Can anyone point me to the right direction, where to find the missing components?

Best regards and thanks in advance, Tobi

Answer 1

Solr field collapsing was released as a part of stable release 3.3
So you can use the latest 3.4 Solr stable build, which should have the components included with it.
As well, it does not require any special components to be included.
Passing group=true&group.field=some_field should have it working without any changes.