Update request processor and field transformer

Use the custom update request processor (URP) to extend the Solr URP. Use the field input/output transformer API as an option to the input/output transformer support in OS Solr.

DataStax Enterprise supports the classic Solr update request processor (URP), a custom URP chain for processing requests and transforming data, and a field input/output transformer API. The DataStax Enterprise custom URP implementation provides similar functionality to the Solr URP chain, but appears as a plugin to Solr. The classic URP is invoked when updating a document using HTTP, the custom URP when updating a table using Cassandra. If both classic and custom URPs are configured, the classic version is executed first.

A field input/output transformer, an alternative for handling update requests, is executed later than a URP at indexing time. See the examples for using the custom URP and the field input/output transformer API.