By default, as RFC 7540 calls for, pushed stream depends on its
associated (parent) stream. There are some situations that this is
sub-optimal. For example, if associated stream is HTML, and server is
configured to push css and javascript files which are in critical
rendering path. Then the default priority scheme is sub-optimal,
since browser typically blocks rendering while waiting for critical
resources. In this case, it is better to at least give pushed stream
the same priority of associated stream, and interleave these streams.
This change gives pushed stream the same priority of associated stream
if pushed stream has content-type "application/javascript" or
"text/css". The pushed stream now depends on the stream which
associated stream depends on. We use the same weight of associated
stream.
This commits enables HTTP/2 server push from HTTP/2 backend to be
relayed to HTTP/2 frontend. To use this feature, --http2-bridge or
--client is required. Server push via Link header field contiues to
work.
Currently, we use same number of HTTP/2 sessions per worker with given
backend addresses. New option to specify the number of HTTP/2 session
per worker will follow.
nghttpx server push is initiated by looking for Link header field from
backend server response. Currently we only enable server push for
HTTP/1 backend and without HTTP/2 proxy mode. The URIs which have
rel=preload are eligible to resource to be pushed.
nghttp2_submit_shutdown_notice() is used to notify the client that
graceful shutdown is started. We expect that after this call, the
server application should send another GOAWAY using
nghttp2_submit_goaway() with appropriate last_stream_id. In this
commit, we also added nghttp2_session_get_last_proc_stream_id(), which
can be used as last_stream_id parameter.
This commit implements graceful shutdown in nghttpx. The integration
test for graceful shutdown is also added.
Previously when requests are issued to HTTP/2 downstream connection,
but it turns out that connection is down, handlers of those requests
are deleted. In some situations, we only know connection is down when
we write something to network, so we'd like to handle this kind of
situation in more robust manner. In this change, certain seconds
passed after last network activity, we first issue PING frame to
downstream connection before issuing new HTTP request. If writing
PING frame is failed, it means connection was lost. In this case,
instead of deleting handler, pending requests are migrated to new
HTTP2/ downstream connection, so that it can continue without
affecting upstream connection.
This commit limits the number of concurrent HTTP/1 downstream
connections to same host. By defualt, it is limited to 8 connections.
--backend-connections-per-frontend option was replaced with
--backend-http1-connections-per-host, which changes the maximum number
of connections per host. This limitation only kicks in when h2 proxy
is used (-s option).
Use the same behaviour the current Google server does: start with 1300
TLS record size and after transmitting 1MiB, change record size to
16384. After 1 second idle time, reset to 1300. Only applies to
HTTP/2 and SPDY upstream connections.
Previously read and write timeouts work independently. When we are
writing response to the client, read timeout still ticks (e.g., HTTP/2
or tunneled HTTPS connection). So read timeout may occur during long
download. This commit fixes this issue. This commit only fixes the
upstream part. We need similar fix for the downstream.
h2-14 now allows extensions to define new error codes. To allow
application callback to access such error codes, we uses uint32_t as
error_code type for structs and function parameters. Previously we
treated unknown error code as INTERNAL_ERROR, but this change removes
this and unknown error code is passed to application callback as is.
Previously we only update consumed flow control window when number of
bytes read in nghttp2 and spdylay callback is 0. Now we notify
nghttp2 library the consumed bytes even if number of bytes read > 0.
This change also uses newly added spdylay_session_consume() API, so we
require spdylay >= 1.3.0.
This option limits the number of backend connections per frontend.
This is meaningful for the combination of HTTP/2 and SPDY frontend and
HTTP/1 backend.
Reworked no automatic WINDOW_UPDATE feature. We added new API
nghttp2_session_consume() which tells the library how many bytes are
consumed by the application. Instead of submitting WINDOW_UPDATE by
the application, the library is now responsible to submit
WINDOW_UPDATE based on consumed bytes. This is more reliable method,
since it enables us to properly send WINDOW_UPDATE for stream and
connection individually. The previous implementation of nghttpx had
broken connection window management.
If SPDY or HTTP/2 ustream is used and HTTP/2 downstream is used, only
call {spdylay,nghttp2}_resume_data when complete DATA frame was read
in backend to avoid to transmit too small DATA frame to the upstream.
Tatsuhiro Tsujikawa