asures HTTP request body sizes.</p></li><li><p><strong>Response Size</strong> (<code>istio_response_bytes</code>): This is a <code>DISTRIBUTION</code> which measures HTTP response body sizes.</p></li><li><p><strong>gRPC Request Message Count</strong> (<code>istio_request_messages_total</code>): This is a <code>COUNTER</code> incremented for every gRPC message sent from a client.</p></li><li><p><strong>gRPC Response Message Count</strong> (<code>istio_response_messages_total</code>): This is a <code>COUNTER<