At this point, you should be familiar with the <requestHandler/> definitions defined in solrconfig.xml—this was explained in Chapter 5, Searching. Any request handlers with class="solr.SearchRequestHandler" are intuitively related to searching. The Java code implementing SearchRequestHandler doesn't actually do any searching! Instead, it maintains a list of SearchComponents that are invoked in sequence for a request. The search components used and their order are configurable.
What follows is our request handler for MusicBrainz releases but modified to explicitly configure the components for the purpose of illustration:
<requestHandler name="mb_releases" class="solr.SearchHandler">
<!-- default values for query parameters -->
<lst name="defaults">
<str name="defType">edismax</str>
<str name="qf">r_name r_a_name^0.4</str>
<str name="pf">r_name^0.5 r_a_name^0.2</str>
<str name="qs">1</str...