Thanks a lot Matt. I did figure it out finally. I introduced EvalJsonPath to extract the attribute and assign it to identifier. In case of single attribute, it worked. In my scenario i have multiple fields in my json - field1 and field2. I need to construct the _id field and send it to ES. I have used EvalJsonPath --> UpdateAttribute --> PutElastiSearchHttp. UpdateAttribute key is configured as _id and value is ${field1}_${field2}. During runtime I can see the attribute value getting constructed for example 111111_SmartAccount_700001, but I do not see the ES index getting populated. PutElastiSearchHttp processor is dropping this value. Any pointers? ... View more