class LogoutController {
    def index = {
        println "IN LOGOUT CONTROLLER TRYING TO LOGOUT"
       redirect uri: SpringSecurityUtils.securityConfig.logout.filterProcessesUrl // '/j_spring_security_logout'
    }

    def accessDenied = {

    }
}

grails.plugins.springsecurity.logout.afterLogoutUrl = 'https://login.test.com/cas/logout'

<g:link controller='Logout'>Logout</g:link>

class LogoutController {
    def index = {
        println "IN LOGOUT CONTROLLER TRYING TO LOGOUT"
        session.invalidate()
        redirect uri: SpringSecurityUtils.securityConfig.logout.filterProcessesUrl
    }
}

logoutProcessService.process(params)
    redirect uri: SpringSecurityUtils.securityConfig.logout.filterProcessesUr
}