How to increment row Identifier Automatically?

[#1]

Hello,

I am learning how to use nifi. i pass a string from HTTP postand then move it to kafka topic and i want it push it into hbase using nifi. While usign PutHbaseJson it asks for row identifier, but my kafka message is only a string. how can i auto increment the row id and store the string messages? 

If anyone knows a better way of sending simple string messages from kafka to hbase using nifi please suggest.

I have attached the snap of simple nifi processors i m using for this.  

And can someone guide me that what and how should i enter values in properties so i can save String message to hbase.

Thank you in Advance.