Logstash Heap Size Increasing

HI,
I'm using logstash version 2.2.1 and facing following issue while running the logstash. Anyone can help me to resolve it.

Error: Your application used more memory than the safety cap of 1G.
Specify -J-Xmx####m to increase it (#### = cap size in MB).
Specify -w for full OutOfMemoryError stack trace

What does your config look like.