Which Filter to use

Elastic Stack Logstash
3

@Christian_Dahlqvist
I am using kv filter now as below. I have numbers as values in few of kv params, but in ElasticSearch they are being indexed as String's. How to index them as numbers !

      kv
		{ 
			source => "message" 
		}

I have response time in log as below .
ResponseTimeMillis=454
But when it's indexed to ES, it's indexed as below.

"ResponseTimeMillis": "454"

I want it to be "ResponseTimeMillis": 454. Is it possible ?