Choas Monkey:AWS EC2: HTTP/1.1 401 Unauthorized error on connecting to eu-central-1(frankfurt)

We are using Chaos monkey for resilience testing on AWS ec2 clients. When chaos monkey is trying to authenticate with the given secret key for frankfurt region, we are getting HTTP/1.1 401 Unauthorized error.We are using AWS SDK for Java.

It is using signature version v2 and eu-central-1(frankfurt) requires v4. How can we set signature version to v4 or what setting we have to make to AWS SDK?

Here is the snapshot of the error:- 2015-01-19 05:37:05.028 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] Sending request -1804412292: POST http://ift.tt/1yJl6H1 HTTP/1.1

2015-01-19 05:37:05.029 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] >> "Action=DescribeInstances&Signature=Ao5fLfM%2B/rOcbdll0LF0K2F9U8NBlgd%2BAwuFk83GOxo%3D&SignatureMethod=HmacSHA256&SignatureVersion=2&Timestamp=2015-01-19T10%3A37%3A05.024Z&Version=2010-06-15&AWSAccessKeyId=xxx"

2015-01-19 05:37:05.029 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] >> POST http://ift.tt/1yJl6H1 HTTP/1.1

2015-01-19 05:37:05.029 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] >> Host: ec2.eu-central-1.amazonaws.com

2015-01-19 05:37:05.030 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] >> Content-Type: application/x-www-form-urlencoded

2015-01-19 05:37:05.030 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] >> Content-Length: 225

2015-01-19 05:37:05.609 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] Receiving response -1804412292: HTTP/1.1 401 Unauthorized 2015-01-19 05:37:05.610 - DEBUG SLF4JLogger - [SLF4JLogger.java:61] << HTTP/1.1 401 Unauthorized