Module ngx_http_v2_module
The ngx_http_v2_module module (1.9.5) provides support for HTTP/2 and supersedes the ngx_http_spdy_module module. This module is not built by default, it should be enabled with the --with-http_v2_module configuration parameter. Before version 1.9.14, buffering of a client request body could not be disabled regardless of proxy_request_buffering, fastcgi_request_buffering, uwsgi_request_buffering, and scgi_request_buffering directive values.
http://nginx.org/en/docs/http/ngx_http_v2_module.html
