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.
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.
It seems that if readcb is not set before SSL/TLS handshake, the
incoming data already available when eventcb (BEV_EVENT_CONNECTED
event) is fired is not further notified after setting new readcb. We
knew this fact and call upstream->on_read() in eventcb, but it is
wrong for HTTP/2. We have to call upstream_http2_connhd_readcb to
check connection preface. Otherwise, we consume it by nghttp2 session
and it is treated as unknown frame and connection preface is not
detected properly.
Libevent Openssl filter is very inconvenient in various respect. The
most annoying thing is it somehow emits data when SSL_shutdown is
called. The reason we introduced this filter solution is drop
connection if TLS renegotiation is detected. This commit implements
renegotiation detection and drop connection without filtering.
NGHTTP2_CLIENT_CONNECTION_PREFACE has the same content with
NGHTTP2_CLIENT_CONNECTION_HEADER, which is now obsoleted by
NGHTTP2_CLIENT_CONNECTION_PREFACE.
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.
4ed4efc does not disable TLS renegotiation at all, if client keeps
rengotiations without sending application data. In this change,
we intercept the raw incoming data from the client and if it is a
renegotiation, drop the connection immediately.
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.
INFO log and its surrounding code are now guarded by
LOG_ENABLED(SEVERITY) macro so that they don't run if log level
threshold is higher. This increases performance because log formatting
is somewhat expensive.
Added macros which log messages from the following components are
prefixed with their component name + object pointer address:
ListenHandler: LISTEN
ThreadEventReceiver: THREAD_RECV
Upstream: UPSTREAM
Downstream: DOWNSTREAM
DownstreamConnection: DCONN
SpdySession: DSPDY
In client mode, now SPDY connection to the backend server is
established per thread. The frontend connections which belong to the
same thread share the SPDY connection.
Tatsuhiro Tsujikawa