Update request processor (URP) and field transformer (FIT)

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

DataStax Enterprise (DSE) recommends using a field input/output transformer (FIT) API.

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.

Note: The DSE custom URP implementation is discouraged. The DSE custom URP implementation is almost always unnecessary.

DSE custom URP provided similar functionality to the Solr URP chain, but appeared 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.

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