I have attached a groovy script that I use to load data into janusgraph. 

The script takes 4 mins to load 1.5 million nodes and 13 mins to load approx 3 million edges.  The server on which the script runs has higher configurations. I looking for different ways to improve the performance of the script. Your feedback will help.

Thank You for the responses. 

Thanks & Regards,

Vinayak