You can use the below code in your controller to get the method name while you try jQuery.Zend.Jsonrpc service call
if($_SERVER['REQUEST_METHOD'] == 'POST') {
$data = json_decode(urldecode($this->getRequest()->getRawBody()));
echo $data->method;
}
if($_SERVER['REQUEST_METHOD'] == 'POST') {
$data = json_decode(urldecode($this->getRequest()->getRawBody()));
echo $data->method;
}