From reading documentation (http://docs.grails.org/latest/ref/Controllers/redirect.html) I got the feeling that if one doesn't pass a value or specifically passes false for absolute parameter then generated redirect would be relative. But I am always getting an absolute redirect with serverURL added.

Relative redirects are required for me because we are using blue green deployment and we are constantly redirected from inactive container to active. (serverURL is set to active container address)