Changes with nginx 1.19.1 07 Jul 2020
*) Change: the "lingering_close", "lingering_time", and "lingering_timeout" directives now work when using HTTP/2.
*) Change: now extra data sent by a backend are always discarded.
*) Change: now after receiving a too short response from a FastCGI server nginx tries to send the available part of the response to the client, and then closes the client connection.
*) Change: now after receiving a response with incorrect length from a gRPC backend nginx stops response processing with an error.
*) Feature: the "min_free" parameter of the "proxy_cache_path", "fastcgi_cache_path", "scgi_cache_path", and "uwsgi_cache_path" directives. Thanks to Adam Bambuch.
*) Bugfix: nginx did not delete unix domain listen sockets during graceful shutdown on the SIGQUIT signal.
*) Bugfix: zero length UDP datagrams were not proxied.
*) Bugfix: proxying to uwsgi backends using SSL might not work. Thanks to Guanzhong Chen.
*) Bugfix: in error handling when using the "ssl_ocsp" directive.
*) Bugfix: on XFS and NFS file systems disk cache size might be calculated incorrectly.
*) Bugfix: "negative size buf in writer" alerts might appear in logs if a memcached server returned a malformed response.