For long-running connections it was possible for the connection
window to become larger than allowed by the protocol because the
window increases claimed by stream handlers were never reclaimed
even if no data was consumed.
The new code applies heuristics to fix this and reduce the number
of WINDOW_UPDATE frames that are sent. It includes six new options
to control that behavior: margin, max and threshold for both the
connection and stream windows. The margin is some extra space
added on top of the requested read size. The max is the maximum
window size at any given time. The threshold is a minimum window
size that must be reached before we even consider sending more
WINDOW_UPDATE frames. We also avoid sending WINDOW_UPDATE frames
when there is already enough space in the window, or when the
read size is 0.
Cowlib is set to master until a new tag is done.
The examples test suite is only useful once in a while
in order to know whether examples were broken, for example
before issuing a release.
The new ws_autobahn test suite isolates the autobahn test
suite so that it can be ignored by default. It's only
useful to run it when working on the Websocket code or
before issuing a release.
The new module is a merge of the Cowboy and Gun HTTP/2
state machines. Using a common code will help future
developments rather than duplicating the work.
A notable change is in how streams are terminated
when the handler stops before the body is sent. The
cowboy_stream:terminate function is now called only
after the body has been sent fully (or the stream
is reset in-between), not when the stop command is
returned. This will most likely have an impact on
metrics but will be closer to reality.
I had to comment a broken test in rfc7231_SUITE that
was cheating, cheating is no longer possible.
This depends on Cowlib master for the time being. A
new Cowlib version will be released once both Cowboy
and Gun are ported to use cow_http2_machine and I'm
satisfied with it.
The miscount occurred because of a faulty iolist split function.
The bug should now be corrected, a PropEr test has been added
and a regression test has also been added.
Instead of tracking Erlang/OTP versions manually in each project,
I can just say OTP-19+ and let the plugin fill in the most recent
patch releases for each version. In addition I will configure the
CI commands to cleanup unneeded versions automatically.
Unfortunately compression will be disabled for 20.1, 20.1.1
and 20.1.2. In additiona I do not recommend 20.1.3 due to
issues inflating some specific sizes.
