Cowboy 2.14 adds experimental support for HTTP/3 WebTransport based on the most recent draft. It also has a new data delivery mechanism for HTTP/2 and HTTP/3 Websocket, providing better performance.
Cowboy 2.14 requires Erlang/OTP 24.0 or greater.
relay data delivery mechanism has been
added to HTTP/2 and HTTP/3 protocols. Using
this mechanism lets the Websocket protocol
bypass stream handlers to forward data from
the connection process to the Websocket
session process, as well as better manage
HTTP/2’s flow control. This results in a
noticeable performance improvement. This
new mechanism can be used by all sub-protocols
built on top of HTTP/2 or HTTP/3 such as
Websocket or the upcoming HTTP/2 WebTransport.
last_modified callback of REST handlers
now accepts undefined as a return value to
allow conditionally providing a timestamp.
enable_connect_protocol, h3_datagram,
wt_max_sessions and for earlier drafts
enable_webtransport. The test suite is
the best place to get started at this time.
dynamic_buffer option introduced in
the previous release has been tweaked to
start at 512 bytes and have its value
changed less abruptly. This is based on
additional work done implementing the same
feature in RabbitMQ.
raw
mode to read file information to avoid a
bottleneck when querying the file server.