server.feature-flags += ("server.graceful-shutdown-timeout" => 10)
After receiving SIGINT or SIGUSR1, lighttpd will gracefully shutdown,
waiting for existing connections to complete. In the case of SIGUSR1,
this wait occurs before restarting lighttpd. The default timeout is
none (unlimited).
When "server.graceful-shutdown-timeout" option is set, it defines the
number of seconds that lighttpd will wait for existing connections to
complete before shutting down the connection.
Sites which expect large uploads or downloads, or those with very slow
clients, might want to set a much longer timeout, e.g 60 seconds
For more immediate graceful restarts, while still allowing existing
connections time to complete, sites should additionally consider
whether or not
server.feature-flags += ("server.graceful-restart-bg" => "enable")
is appropriate and compatible with their lighttpd.conf settings
graceful and (nearly) immediate lighttpd restart option
For *some* configurations, it *may* be safe to background the current
lighttpd server (or workers) to continue processing active requests
and, in parallel, to start up a new lighttpd server with a new
configuration. For other configurations, doing so might not be safe!
Therefore, this option must be explicitly configured to enable:
server.feature-flags += ("server.graceful-restart-bg" => "enable")
server.systemd-socket-activation = "enable"
Along with enabling server.feature-flags "server.graceful-restart-bg",
enabling server.systemd-socket-activation allows transfer of open
listening sockets to the new lighttpd server instance, and occurs
without closing the listening sockets and without destroying the
kernel listen backlog queue on the socket.
Safe configurations may include lighttpd.conf which connect to
standalone backend daemons, e.g. proxying to other servers,
including PHP-FPM backends.
Unsafe configurations include lighttpd.conf which use "bin-path" option
in *.server configs, instructing lighttpd to execute the backends.
Using the graceful-and-immediate-restart option is likely *unsafe* if
the backend daemon expects only one instance of itself to run at a time.
Current implementation of graceful and immediate restart option keeps
the backgrounded lighttpd in the same process group, so that subsequent
SIGINT or SIGTERM will shut down both the new and the backgrounded
servers. (An alternative option (commented out in the code) is to
background and detach from the new lighttpd process.) Regardless,
existing subprocesses, such as CGI, remain in original process group.
As a result, the new lighttpd server may receive SIGCHLD for unknown
processes inherited from the old server, which the new lighttpd server
will reap and discard. The original lighttpd server, now a child, will
be unable to detect exit or reap and report status on those pre-existing
subprocesses.
Graceful restart is triggered in lighttpd by sending lighttpd SIGUSR1.
If lighttpd is configured with workers, then SIGINT (not SIGUSR1) is
sent to the process group, including other processes started by
lighttpd, e.g. CGI. To work well with graceful restart, CGI scripts and
other processes should trap SIGINT (and SIGUSR1 for good measure).
Long-running scripts may want to checkpoint and close, e.g. a CGI script
implementing a long-running websocket connection.
Location response header is permitted to use relative-path in
RFC 7231 Section 7.1.2. Location
Prefer relative path in redirection for the benefit of reverse proxies
and CDNs. Doing so also avoids potentially disclosing internal schemes
and server names which client might not be able to directly reach.
To restore prior behavior of sending a fully-qualified absolute URI:
server.feature-flags += ("absolute-dir-redirect" => "enable")
x-ref:
https://bz.apache.org/bugzilla/show_bug.cgi?id=63357
(subsequently incrementally updated using git rebase)
huge props and many thank yous to writers of testing tools used while
developing HTTP/2 support in lighttpd:
h2spec - conformance testing tool for HTTP/2 implementation
https://github.com/summerwind/h2spec
h2load - HTTP/2 benchmarking tool
https://nghttp2.org/documentation/h2load-howto.html
curl - command line tool and library for transferring data with URLs
https://curl.haxx.se/
r->con->reqbody_read() replaces connection_handle_read_post_state()
future: might provide different callbacks for request body with
Content-Length versus request body sent via Transfer-Encoding: chunked
(pedantic; no impact)
upon error, server will exit, so the impact of momentarily leaking fd
has no impact. This commit holds the fd in srv->stdin_fd to address
Coverity warning about leaking fd when using server.bind = "/dev/stdin"
NB: r->tmp_buf == srv->tmp_buf (pointer is copied for quicker access)
NB: request read and write chunkqueues currently point to connection
chunkqueues; per-request and per-connection chunkqueues are
not distinct from one another
con->read_queue == r->read_queue
con->write_queue == r->write_queue
NB: in the future, a separate connection config may be needed for
connection-level module hooks. Similarly, might need to have
per-request chunkqueues separate from per-connection chunkqueues.
Should probably also have a request_reset() which is distinct from
connection_reset().
fdevent.c no longer directly uses struct server *srv
srv->srvconf.max_fds (if set) is used to set rlimits
set max_conns in server.c after fdevent_init(), which sets srv->max_fds
using srv->srvconf.max_fds (if set) as input hint
e.g. different server.errorlog for different virtual hosts
Also, support different server.breakagelog to have separate script
error logs, applicable to mod_cgi and mod_ssi exec.
use global rather than passing around (server *) just for that
li_itostrn() and li_utostrn() return string length
(rather than requiring subsequent strlen() to find length)
convert all log_error_write() to log_error() and pass (log_error_st *)
use con->errh in preference to srv->errh (even though currently same)
avoid passing (server *) when previously used only for logging (errh)
Glenn Strauss