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.
--no-location-rewrite option disallows location header rewrite on
--http2-bridge, --client and default mode. This option is useful when
connecting nghttpx proxy with --http2-bridge to backend nghttpx with
http2-proxy mode.
It might be useful to clean the unused stream out to make up the room
for new streams. On the other hand, proxy should maintain the
connection between upstream client and downstream server and they have
the timeout for their own. Proxy just reacts to their decision.
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.
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.
It looks like setting read-rate and read-burst to 0 makes busy loop.
It seems a bug. On the other hand, we most likely want per-thread
rate limit rather than per-connection. So we decided to drop them.
Cipher suites are chosen by DHE and ECDHE ciphers + GCM (AEAD). Now
default cipher list is the one recommended by Mozilla web site. The
--honor-cipher-order option is removed and now it is always assumed.
It seems that specifyig '*' to node parameter in getaddrinfo() is
treated as specifying NULL, but it is not documented. So rather than
relying on this feature, we explicitly treat '*' as "wildcard" address
and specify NULL to node parameter in getaddrinfo().
Now '*,3000' is a default value of --frontend option. Specyfing '*'
binds all addresses including both IPv4 and IPv6.
To make adding new option easier, we decided to make the details of
option struct private and hide it from public API. We provide
functions to set individual option value.
The existing options --{read,write}-{rate,burst} are per connection.
The new options --worker-{read,write}-{rate,burst} are per worker
thread, which is overall rate limit of all connections worker handles.
Tatsuhiro Tsujikawa
Nicholas Hurley