Update request processor and field transformer (FIT) 

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

DataStax Enterprise (DSE) supports the classic Apache Lucene® update request processor (URP), a custom URP chain for processing requests and transforming data, and a field input/output transformer (FIT) API. The DSE 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 and the custom URP is invoked when updating a table using DSE. If both classic and custom URPs are configured, the classic version is executed first. The custom URP chain and the FIT API work with CQL and HTTP updates.

A field input/output transformer, an alternative for handling update requests, is executed later than a URP at indexing time. See the DataStax Developer Blog post An Introduction to DSE Field Transformers.

Examples are provided for using the custom URP and the field input/output transformer API.