Previously we wrongly handles stream per connection when h2 backend
failed or closed. If upstream is h2 or spdy, streams which are not
associated to the failed h2 backend are also handled, which is
unnecessary.
We added --frontend-http2-window-size,
--frontend-http2-connection-window-size, --backend-http2-window-size,
and --backend-http2-connection-window-size option to replace existing
*-bits options. The old options are not flexible because they only
specify number of bits. Now we can specify integer value, with
possible g, m, and k unit. The old options are still available for
backend compatibility, but are deprecated.
There is a discussion in httpbis mailing list which argues that
dependency tree is for client, and changing it in server side is not
what client expects.
https://lists.w3.org/Archives/Public/ietf-http-wg/2016JulSep/0416.html
Currently, we make pushed stream depend on the parent stream of
associated stream (that is main HTML in most of the cases), so that
associated stream and pushed stream become siblings. In this case, we
also observed that these resources complete each other to get its
parent weight. This means that the delivery of associated stream is
delayed by pushed streams.
So at this moment, it is not a good idea to change pushed stream
priority in a way we do currently.
For HTTP/2, read timer starts when there is no downstream, and timer
stops when there is at least one downstream. For HTTP/1, read timer
starts when request handling finished, and timer stops when request
handling starts.
For those connections via frontend with api parameter, they use solely
APIDownstreamConnection.
In this commit, APIDownstreamConnection just consumes all request
body, and do nothing. The next few commits implements our first API
endpoint: /v1/api/dynamicconfig.
It is very hard to support multiple protocols in backend while
retaining multiple mode settings. Therefore, we dropped modes except
for default and HTTP/2 proxy mode. The other removed modes can be
emulated using combinations of options. Now the backend connection is
not encrypted by default. To enable encryption on backend connection,
use --backend-tls option.
Tatsuhiro Tsujikawa