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.
The nghttp2 library itself is still h2-14. To experiment with the
implementations to require h2-16 to test new features (e.g.,
prioritization), nghttp, nghttpx, nghttpd and h2load now support h2-16
as well as h2-14. Cleartext HTTP Upgrade is still limited to h2-14
however.
This commit adds functionality to customize access logging format in
nghttpx. The format variables are inspired by nginx. The default
format is combined format.
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.
nghttpx supports hot deploy feature using signals. The host deploy in
nghttpx is multi step process. First send USR2 signal to nghttpx
process. It will do fork and execute new executable, using same
command-line arguments and environment variables. At this point, both
current and new processes can accept requests. To gracefully shutdown
current process, send QUIT signal to current nghttpx process. When
all existing frontend connections are done, the current process will
exit. At this point, only new nghttpx process exists and serves
incoming requests.
This change rewrites logging system of nghttpx. Previously access log
and error log are written to stderr or syslog and there was no option
to change stderr to something else. With this change, file path of
access log and error log can be configured separately and logging to
regular file is now added. To support rotating log, if SIGUSR1 signal
is received by nghttpx, it closes the current log files and reopen it
with the same name. The format of access log is changed and has same
look of apache's. But not all columns are not supported yet.
We thought that this kind of rewrite can be achieved by the configuration
of the backend severs, but in some configuration, however, it may get
complicated. So we decided to implement at least location rewrite in
nghttpx.
This commit also contains a fix to the bug which prevents the http2
backend request from concatenating header fields with the same value.
Tatsuhiro Tsujikawa
Lucas Pardue