A field _indexed_at_tdt added when I index documents.

I'm indexing documents in solr with Spark and it's missing the a field _indexed_at_tdt who is doesn't exist in my documents. I have added this field in my schema, why is this field being added? any solution?

Trying to index document in Solr with solr-spark library

I'm getting some errors when I try to use the solr-sparl library getting the error *KeeperErrorCode = NoNode for /live_nodes*. I download the library and compile with the branch_4.x since I'm using Cloudera 5.5.1 and Solr 4.10.3. I checked the logs of Solr and Zookeeper and I didn't find any