As you may know HTTP/1.1 can allow you leave the socket open between HTTP requests leveraging the famous Keep-Alive connection. But, what less people exploit is the feature of just launch a burst of multiple sequential HTTP/1.1 requests without wait for the response in the middle time, Then the responses should return to you the same order paying the latency time just one time. (This consumption pattern is encouraged in Redis clients for example).
I know this pattern has been improved in HTTP/2 with the multiplexing feature but my concern right now is if I can use that pipelining pattern with the tornado library exploiting its async features, or may be other library capable?
No, Tornado does not support HTTP/1.1 pipelining. It won't start serving the second request until the response to the first request has been written.