And enabling the respective pre-defined writers

Understanding Apache Solr

Directive

	Using this directive, you can subscribe to update events when IndexWriters are updating the index. The listeners can either be run at the time of "postCommit" or "postOptimize"
Query
	By setting parameters in this directive, you can control how a request will be processed by SolrDispatchFilter.

searchComponent	Search components in Solr enable additional logic that can be used by the search handler to provide a better searching experience. These are described in Appendix, Use Cases for Big Data Search.


queryParser	The query parser directive tells Apache Solr which query parser to be used for parsing the query and creating Lucene Query Objects. Apache Solr contains pre-defined query parsers such as lucene (default), DisMax (based on weights of fields), edismax (similar to DisMax with some additional features), and others.

Chapter 2

The following types of plugins can be created with Apache Solr:



Request handler	Request handlers are used to provide a REST endpoint from the Solr instance to get some work done.

Request handlers in Solr are responsible for handling requests. Each request handler can be associated with one relative URL: for example, /search, /select. A request handler that provides search capabilities is called a search handler. There are more than 25 rplete

There are search handlers that provide searching capabilities on a Solr-based index (For example, DisMaxRequestHandler and SearchHandler); similarly, there are update handlers that provide support for uploading documents to Solr (For example, DataImportHandler and CSVUpdateRequestHandler). RealTimeGetHandler
provides the latest stored fields of any document. UpdateRequestHandlers are responsible to process the updating of an index. Similarly, CSVRequestHandler and JsonUpdateRequestHandler take the responsibility of updating the indexes with the CSV and JSON formats. ExtractingRequestHandler uses Apache Tika to extract the text from different file formats.