Openfire Crashes, High Memory Usage,

Hi i am facing an issues with the open fire Ver 4.0.2, the Open fire server is taking high memory, multiple processes when checked with htop (Screen Shot attached). its a development phase checking by 15-20 Concurrent users. Need help on asap Bases.

Server : Amazon Linux (Centos Base)

Server type t2.micro (1vCPU and 1GiB ram)

Openfire Version= 4.0.2