Re-Indexing Solr Collections After Upgrading to CDH 6
After upgrading to CDH 6, your Solr collections will be automatically recreated with the updated configuration, but the collections are empty. Cloudera does not support upgrading the underlying index files from CDH 5 to CDH 6, so you must re-index your collections.
Apache Solr does not have dedicated re-indexing functionality. To re-index a collection, you must perform whatever indexing procedure you initially used to index your documents. For more information on indexing, see Indexing Data Using Cloudera Search.
If you are storing documents in Cloudera Search itself, contact Cloudera Support for assistance.