1 # -*- encoding: binary -*-
2 require "unicorn/ssl_server"
4 # This is the process manager of Unicorn. This manages worker
5 # processes which in turn handle the I/O and application process.
6 # Listener sockets are started in the master process and shared with
7 # forked worker children.
9 # Users do not need to know the internals of this class, but reading the
10 # {source}[http://bogomips.org/unicorn.git/tree/lib/unicorn/http_server.rb]
11 # is education for programmers wishing to learn how \Unicorn works.
12 # See Unicorn::Configurator for information on how to configure \Unicorn.
13 class Unicorn::HttpServer
15 attr_accessor :app, :request, :timeout, :worker_processes,
16 :before_fork, :after_fork, :before_exec,
17 :listener_opts, :preload_app,
18 :reexec_pid, :orig_app, :init_listeners,
19 :master_pid, :config, :ready_pipe, :user
21 attr_reader :pid, :logger
22 include Unicorn::SocketHelper
23 include Unicorn::HttpResponse
24 include Unicorn::SSLServer
26 # backwards compatibility with 1.x
27 Worker = Unicorn::Worker
29 # all bound listener sockets
32 # listeners we have yet to bind
35 # This hash maps PIDs to Workers
38 # We use SELF_PIPE differently in the master and worker processes:
40 # * The master process never closes or reinitializes this once
41 # initialized. Signal handlers in the master process will write to
42 # it to wake up the master from IO.select in exactly the same manner
43 # djb describes in http://cr.yp.to/docs/selfpipe.html
45 # * The workers immediately close the pipe they inherit from the
46 # master and replace it with a new pipe after forking. This new
47 # pipe is also used to wakeup from IO.select from inside (worker)
48 # signal handlers. However, workers *close* the pipe descriptors in
49 # the signal handlers to raise EBADF in IO.select instead of writing
50 # like we do in the master. We cannot easily use the reader set for
51 # IO.select because LISTENERS is already that set, and it's extra
52 # work (and cycles) to distinguish the pipe FD from the reader set
53 # once IO.select returns. So we're lazy and just close the pipe when
54 # a (rare) signal arrives in the worker and reinitialize the pipe later.
57 # signal queue used for self-piping
60 # list of signals we care about and trap in master.
61 QUEUE_SIGS = [ :WINCH, :QUIT, :INT, :TERM, :USR1, :USR2, :HUP, :TTIN, :TTOU ]
64 # We populate this at startup so we can figure out how to reexecute
65 # and upgrade the currently running instance of Unicorn
66 # This Hash is considered a stable interface and changing its contents
67 # will allow you to switch between different installations of Unicorn
68 # or even different installations of the same applications without
69 # downtime. Keys of this constant Hash are described as follows:
71 # * 0 - the path to the unicorn/unicorn_rails executable
72 # * :argv - a deep copy of the ARGV array the executable originally saw
73 # * :cwd - the working directory of the application, this is where
74 # you originally started Unicorn.
76 # To change your unicorn executable to a different path without downtime,
77 # you can set the following in your Unicorn config file, HUP and then
78 # continue with the traditional USR2 + QUIT upgrade steps:
80 # Unicorn::HttpServer::START_CTX[0] = "/home/bofh/1.9.2/bin/unicorn"
82 :argv => ARGV.map { |arg| arg.dup },
85 # We favor ENV['PWD'] since it is (usually) symlink aware for Capistrano
87 START_CTX[:cwd] = begin
88 a = File.stat(pwd = ENV['PWD'])
89 b = File.stat(Dir.pwd)
90 a.ino == b.ino && a.dev == b.dev ? pwd : Dir.pwd
96 # Creates a working server on host:port (strange things happen if
97 # port isn't a Number). Use HttpServer::run to start the server and
98 # HttpServer.run.join to join the thread that's processing
99 # incoming requests on the socket.
100 def initialize(app, options = {})
102 @request = Unicorn::HttpRequest.new
104 options = options.dup
105 @ready_pipe = options.delete(:ready_pipe)
106 @init_listeners = options[:listeners] ? options[:listeners].dup : []
107 options[:use_defaults] = true
108 self.config = Unicorn::Configurator.new(options)
109 self.listener_opts = {}
111 # we try inheriting listeners first, so we bind them later.
112 # we don't write the pid file until we've bound listeners in case
113 # unicorn was started twice by mistake. Even though our #pid= method
114 # checks for stale/existing pid files, race conditions are still
115 # possible (and difficult/non-portable to avoid) and can be likely
116 # to clobber the pid if the second start was in quick succession
117 # after the first, so we rely on the listener binding to fail in
118 # that case. Some tests (in and outside of this source tree) and
119 # monitoring tools may also rely on pid files existing before we
120 # attempt to connect to the listener(s)
121 config.commit!(self, :skip => [:listeners, :pid])
125 # Runs the thing. Returns self so you can run join on it
128 # this pipe is used to wake us up from select(2) in #join when signals
129 # are trapped. See trap_deferred.
132 # setup signal handlers before writing pid file in case people get
133 # trigger happy and send signals as soon as the pid file exists.
134 # Note that signals don't actually get handled until the #join method
135 QUEUE_SIGS.each { |sig| trap(sig) { SIG_QUEUE << sig; awaken_master } }
136 trap(:CHLD) { awaken_master }
138 # write pid early for Mongrel compatibility if we're not inheriting sockets
139 # This was needed for compatibility with some health checker a long time
140 # ago. This unfortunately has the side effect of clobbering valid PID
142 self.pid = config[:pid] unless ENV["UNICORN_FD"]
145 build_app! if preload_app
148 # Assuming preload_app==false, we drop the pid file after the app is ready
149 # to process requests. If binding or build_app! fails with
150 # preload_app==true, we'll never get here and the parent will recover
151 self.pid = config[:pid] if ENV["UNICORN_FD"]
153 spawn_missing_workers
157 # replaces current listener set with +listeners+. This will
158 # close the socket if it will not exist in the new listener set
159 def listeners=(listeners)
160 cur_names, dead_names = [], []
161 listener_names.each do |name|
163 # mark unlinked sockets as dead so we can rebind them
164 (File.socket?(name) ? cur_names : dead_names) << name
169 set_names = listener_names(listeners)
170 dead_names.concat(cur_names - set_names).uniq!
172 LISTENERS.delete_if do |io|
173 if dead_names.include?(sock_name(io))
174 IO_PURGATORY.delete_if do |pio|
175 pio.fileno == io.fileno && (pio.close rescue nil).nil? # true
177 (io.close rescue nil).nil? # true
179 set_server_sockopt(io, listener_opts[sock_name(io)])
184 (set_names - cur_names).each { |addr| listen(addr) }
187 def stdout_path=(path); redirect_io($stdout, path); end
188 def stderr_path=(path); redirect_io($stderr, path); end
191 Unicorn::HttpRequest::DEFAULTS["rack.logger"] = @logger = obj
194 def clobber_pid(path)
195 unlink_pid_safe(@pid) if @pid
198 tmp = "#{File.dirname(path)}/#{rand}.#$$"
199 File.open(tmp, File::RDWR|File::CREAT|File::EXCL, 0644)
204 File.rename(fp.path, path)
209 # sets the path for the PID file of the master process
212 if x = valid_pid?(path)
213 return path if pid && path == pid && x == $$
214 if x == reexec_pid && pid =~ /\.oldbin\z/
215 logger.warn("will not set pid=#{path} while reexec-ed "\
216 "child is running PID:#{x}")
219 raise ArgumentError, "Already running on PID:#{x} " \
220 "(or pid=#{path} is stale)"
224 # rename the old pid if possible
227 File.rename(@pid, path)
228 rescue Errno::ENOENT, Errno::EXDEV
229 # a user may have accidentally removed the original,
230 # obviously cross-FS renames don't work, either.
239 # add a given address to the +listeners+ set, idempotently
240 # Allows workers to add a private, per-process listener via the
241 # after_fork hook. Very useful for debugging and testing.
242 # +:tries+ may be specified as an option for the number of times
243 # to retry, and +:delay+ may be specified as the time in seconds
244 # to delay between retries.
245 # A negative value for +:tries+ indicates the listen will be
246 # retried indefinitely, this is useful when workers belonging to
247 # different masters are spawned during a transparent upgrade.
248 def listen(address, opt = {}.merge(listener_opts[address] || {}))
249 address = config.expand_addr(address)
250 return if String === address && listener_names.include?(address)
252 delay = opt[:delay] || 0.5
253 tries = opt[:tries] || 5
255 io = bind_listen(address, opt)
256 unless Kgio::TCPServer === io || Kgio::UNIXServer === io
257 prevent_autoclose(io)
260 logger.info "listening on addr=#{sock_name(io)} fd=#{io.fileno}"
263 rescue Errno::EADDRINUSE => err
264 logger.error "adding listener failed addr=#{address} (in use)"
265 raise err if tries == 0
267 logger.error "retrying in #{delay} seconds " \
268 "(#{tries < 0 ? 'infinite' : tries} tries left)"
272 logger.fatal "error adding listener addr=#{address}"
277 # monitors children and receives signals forever
278 # (or until a termination signal is sent). This handles signals
279 # one-at-a-time time and we'll happily drop signals in case somebody
280 # is signalling us too often.
283 last_check = Time.now
286 logger.info "master process ready" # test_exec.rb relies on this message
288 @ready_pipe.syswrite($$.to_s)
289 @ready_pipe = @ready_pipe.close rescue nil
295 # avoid murdering workers after our master process (or the
296 # machine) comes out of suspend/hibernation
297 if (last_check + @timeout) >= (last_check = Time.now)
298 sleep_time = murder_lazy_workers
300 sleep_time = @timeout/2.0 + 1
301 @logger.debug("waiting #{sleep_time}s after suspend/hibernation")
303 maintain_worker_count if respawn
304 master_sleep(sleep_time)
305 when :QUIT # graceful shutdown
307 when :TERM, :INT # immediate shutdown
310 when :USR1 # rotate logs
311 logger.info "master reopening logs..."
312 Unicorn::Util.reopen_logs
313 logger.info "master done reopening logs"
314 kill_each_worker(:USR1)
315 when :USR2 # exec binary, stay alive in case something went wrong
318 if Unicorn::Configurator::RACKUP[:daemonized]
320 logger.info "gracefully stopping all workers"
321 kill_each_worker(:QUIT)
322 self.worker_processes = 0
324 logger.info "SIGWINCH ignored because we're not daemonized"
328 self.worker_processes += 1
330 self.worker_processes -= 1 if self.worker_processes > 0
333 if config.config_file
335 else # exec binary and exit if there's no config file
336 logger.info "config_file not present, reexecuting binary"
341 Unicorn.log_error(@logger, "master loop error", e)
343 stop # gracefully shutdown all workers on our way out
344 logger.info "master complete"
345 unlink_pid_safe(pid) if pid
348 # Terminates all workers, but does not exit master process
349 def stop(graceful = true)
351 limit = Time.now + timeout
352 until WORKERS.empty? || Time.now > limit
353 kill_each_worker(graceful ? :QUIT : :TERM)
357 kill_each_worker(:KILL)
361 Unicorn::HttpRequest.input_class.method_defined?(:rewind)
364 def rewindable_input=(bool)
365 Unicorn::HttpRequest.input_class = bool ?
366 Unicorn::TeeInput : Unicorn::StreamInput
369 def client_body_buffer_size
370 Unicorn::TeeInput.client_body_buffer_size
373 def client_body_buffer_size=(bytes)
374 Unicorn::TeeInput.client_body_buffer_size = bytes
377 def trust_x_forwarded
378 Unicorn::HttpParser.trust_x_forwarded?
381 def trust_x_forwarded=(bool)
382 Unicorn::HttpParser.trust_x_forwarded = bool
385 def check_client_connection
386 Unicorn::HttpRequest.check_client_connection
389 def check_client_connection=(bool)
390 Unicorn::HttpRequest.check_client_connection = bool
395 # wait for a signal hander to wake us up and then consume the pipe
396 def master_sleep(sec)
397 IO.select([ SELF_PIPE[0] ], nil, nil, sec) or return
398 SELF_PIPE[0].kgio_tryread(11)
402 SELF_PIPE[1].kgio_trywrite('.') # wakeup master process from select
405 # reaps all unreaped workers
408 wpid, status = Process.waitpid2(-1, Process::WNOHANG)
410 if reexec_pid == wpid
411 logger.error "reaped #{status.inspect} exec()-ed"
413 self.pid = pid.chomp('.oldbin') if pid
416 worker = WORKERS.delete(wpid) and worker.close rescue nil
417 m = "reaped #{status.inspect} worker=#{worker.nr rescue 'unknown'}"
418 status.success? ? logger.info(m) : logger.error(m)
425 # reexecutes the START_CTX with a new binary
429 Process.kill(0, reexec_pid)
430 logger.error "reexec-ed child already running PID:#{reexec_pid}"
438 old_pid = "#{pid}.oldbin"
440 self.pid = old_pid # clear the path for a new pid file
442 logger.error "old PID:#{valid_pid?(old_pid)} running with " \
443 "existing pid=#{old_pid}, refusing rexec"
446 logger.error "error writing pid=#{old_pid} #{e.class} #{e.message}"
451 self.reexec_pid = fork do
453 LISTENERS.each do |sock|
454 # IO#close_on_exec= will be available on any future version of
455 # Ruby that sets FD_CLOEXEC by default on new file descriptors
456 # ref: http://redmine.ruby-lang.org/issues/5041
457 sock.close_on_exec = false if sock.respond_to?(:close_on_exec=)
458 listener_fds[sock.fileno] = sock
460 ENV['UNICORN_FD'] = listener_fds.keys.join(',')
461 Dir.chdir(START_CTX[:cwd])
462 cmd = [ START_CTX[0] ].concat(START_CTX[:argv])
464 # avoid leaking FDs we don't know about, but let before_exec
465 # unset FD_CLOEXEC, if anything else in the app eventually
466 # relies on FD inheritence.
467 (3..1024).each do |io|
468 next if listener_fds.include?(io)
469 io = IO.for_fd(io) rescue next
470 prevent_autoclose(io)
471 io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
474 # exec(command, hash) works in at least 1.9.1+, but will only be
475 # required in 1.9.4/2.0.0 at earliest.
476 cmd << listener_fds if RUBY_VERSION >= "1.9.1"
477 logger.info "executing #{cmd.inspect} (in #{Dir.pwd})"
478 before_exec.call(self)
481 proc_name 'master (old)'
484 # forcibly terminate all workers that haven't checked in in timeout seconds. The timeout is implemented using an unlinked File
485 def murder_lazy_workers
486 next_sleep = @timeout - 1
488 WORKERS.dup.each_pair do |wpid, worker|
490 0 == tick and next # skip workers that haven't processed any clients
492 tmp = @timeout - diff
494 next_sleep > tmp and next_sleep = tmp
498 logger.error "worker=#{worker.nr} PID:#{wpid} timeout " \
499 "(#{diff}s > #{@timeout}s), killing"
500 kill_worker(:KILL, wpid) # take no prisoners for timeout violations
502 next_sleep <= 0 ? 1 : next_sleep
505 def after_fork_internal
506 @ready_pipe.close if @ready_pipe
507 Unicorn::Configurator::RACKUP.clear
508 @ready_pipe = @init_listeners = @before_exec = @before_fork = nil
510 srand # http://redmine.ruby-lang.org/issues/4338
512 # The OpenSSL PRNG is seeded with only the pid, and apps with frequently
513 # dying workers can recycle pids
514 OpenSSL::Random.seed(rand.to_s) if defined?(OpenSSL::Random)
517 def spawn_missing_workers
519 until (worker_nr += 1) == @worker_processes
520 WORKERS.value?(worker_nr) and next
521 worker = Worker.new(worker_nr)
522 before_fork.call(self, worker)
524 WORKERS[pid] = worker
532 @logger.error(e) rescue nil
536 def maintain_worker_count
537 (off = WORKERS.size - worker_processes) == 0 and return
538 off < 0 and return spawn_missing_workers
539 WORKERS.dup.each_pair { |wpid,w|
540 w.nr >= worker_processes and kill_worker(:QUIT, wpid) rescue nil
544 # if we get any error, try to write something back to the client
545 # assuming we haven't closed the socket, but don't get hung up
546 # if the socket is already closed or broken. We'll always ensure
547 # the socket is closed at the end of this function
548 def handle_error(client, e)
550 when EOFError,Errno::ECONNRESET,Errno::EPIPE,Errno::ENOTCONN
551 # client disconnected on us and there's nothing we can do
552 when Unicorn::RequestURITooLongError
554 when Unicorn::RequestEntityTooLargeError
556 when Unicorn::HttpParserError # try to tell the client they're bad
559 Unicorn.log_error(@logger, "app error", e)
563 client.kgio_trywrite(err_response(code, @request.response_start_sent))
569 def expect_100_response
570 if @request.response_start_sent
571 Unicorn::Const::EXPECT_100_RESPONSE_SUFFIXED
573 Unicorn::Const::EXPECT_100_RESPONSE
577 # once a client is accepted, it is processed in its entirety here
578 # in 3 easy steps: read request, call app, write app response
579 def process_client(client)
580 status, headers, body = @app.call(env = @request.read(client))
581 return if @request.hijacked?
583 if 100 == status.to_i
584 client.write(expect_100_response)
585 env.delete(Unicorn::Const::HTTP_EXPECT)
586 status, headers, body = @app.call(env)
587 return if @request.hijacked?
589 @request.headers? or headers = nil
590 http_response_write(client, status, headers, body,
591 @request.response_start_sent)
592 unless client.closed? # rack.hijack may've close this for us
593 client.shutdown # in case of fork() in Rack app
594 client.close # flush and uncork socket immediately, no keepalive
597 handle_error(client, e)
600 EXIT_SIGS = [ :QUIT, :TERM, :INT ]
601 WORKER_QUEUE_SIGS = QUEUE_SIGS - EXIT_SIGS
603 # gets rid of stuff the worker has no business keeping track of
604 # to free some resources and drops all sig handlers.
605 # traps for USR1, USR2, and HUP may be set in the after_fork Proc
607 def init_worker_process(worker)
608 # we'll re-trap :QUIT later for graceful shutdown iff we accept clients
609 EXIT_SIGS.each { |sig| trap(sig) { exit!(0) } }
610 exit!(0) if (SIG_QUEUE & EXIT_SIGS)[0]
611 WORKER_QUEUE_SIGS.each { |sig| trap(sig, nil) }
612 trap(:CHLD, 'DEFAULT')
614 proc_name "worker[#{worker.nr}]"
618 LISTENERS.each { |sock| sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
619 after_fork.call(self, worker) # can drop perms
620 worker.user(*user) if user.kind_of?(Array) && ! worker.switched
621 self.timeout /= 2.0 # halve it for select()
623 build_app! unless preload_app
625 @after_fork = @listener_opts = @orig_app = nil
628 def reopen_worker_logs(worker_nr)
629 logger.info "worker=#{worker_nr} reopening logs..."
630 Unicorn::Util.reopen_logs
631 logger.info "worker=#{worker_nr} done reopening logs"
634 logger.error(e) rescue nil
635 exit!(77) # EX_NOPERM in sysexits.h
638 # runs inside each forked worker, this sits around and waits
639 # for connections and doesn't die until the parent dies (or is
640 # given a INT, QUIT, or TERM signal)
641 def worker_loop(worker)
643 init_worker_process(worker)
644 nr = 0 # this becomes negative if we need to reopen logs
648 # closing anything we IO.select on will raise EBADF
649 trap(:USR1) { nr = -65536; SELF_PIPE[0].close rescue nil }
650 trap(:QUIT) { worker = nil; LISTENERS.each { |s| s.close rescue nil }.clear }
651 logger.info "worker=#{worker.nr} ready"
654 nr < 0 and reopen_worker_logs(worker.nr)
657 worker.tick = Time.now.to_i
658 while sock = ready.shift
659 if client = sock.kgio_tryaccept
660 process_client(client)
662 worker.tick = Time.now.to_i
667 # make the following bet: if we accepted clients this round,
668 # we're probably reasonably busy, so avoid calling select()
669 # and do a speculative non-blocking accept() on ready listeners
670 # before we sleep again in select().
671 unless nr == 0 # (nr < 0) => reopen logs (unlikely)
676 ppid == Process.ppid or return
678 # timeout used so we can detect parent death:
679 worker.tick = Time.now.to_i
680 ret = IO.select(l, nil, SELF_PIPE, @timeout) and ready = ret[0]
682 redo if nr < 0 && (Errno::EBADF === e || IOError === e) # reopen logs
683 Unicorn.log_error(@logger, "listen loop error", e) if worker
687 # delivers a signal to a worker and fails gracefully if the worker
688 # is no longer running.
689 def kill_worker(signal, wpid)
690 Process.kill(signal, wpid)
692 worker = WORKERS.delete(wpid) and worker.close rescue nil
695 # delivers a signal to each worker
696 def kill_each_worker(signal)
697 WORKERS.keys.each { |wpid| kill_worker(signal, wpid) }
700 # unlinks a PID file at given +path+ if it contains the current PID
701 # still potentially racy without locking the directory (which is
702 # non-portable and may interact badly with other programs), but the
703 # window for hitting the race condition is small
704 def unlink_pid_safe(path)
705 (File.read(path).to_i == $$ and File.unlink(path)) rescue nil
708 # returns a PID if a given path contains a non-stale PID file,
711 wpid = File.read(path).to_i
713 Process.kill(0, wpid)
716 logger.info "pid=#{path} possibly stale, got EPERM signalling PID:#{wpid}"
718 rescue Errno::ESRCH, Errno::ENOENT
719 # don't unlink stale pid files, racy without non-portable locking...
724 logger.info "reloading config_file=#{config.config_file}"
725 config[:listeners].replace(@init_listeners)
728 kill_each_worker(:QUIT)
729 Unicorn::Util.reopen_logs
731 build_app! if preload_app
732 logger.info "done reloading config_file=#{config.config_file}"
733 rescue StandardError, LoadError, SyntaxError => e
734 Unicorn.log_error(@logger,
735 "error reloading config_file=#{config.config_file}", e)
736 self.app = loaded_app
739 # returns an array of string names for the given listener array
740 def listener_names(listeners = LISTENERS)
741 listeners.map { |io| sock_name(io) }
745 if app.respond_to?(:arity) && app.arity == 0
746 if defined?(Gem) && Gem.respond_to?(:refresh)
747 logger.info "Refreshing Gem list"
755 $0 = ([ File.basename(START_CTX[0]), tag
756 ]).concat(START_CTX[:argv]).join(' ')
759 def redirect_io(io, path)
760 File.open(path, 'ab') { |fp| io.reopen(fp) } if path
765 SELF_PIPE.each { |io| io.close rescue nil }
766 SELF_PIPE.replace(Kgio::Pipe.new)
767 SELF_PIPE.each { |io| io.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) }
770 def inherit_listeners!
771 # inherit sockets from parents, they need to be plain Socket objects
772 # before they become Kgio::UNIXServer or Kgio::TCPServer
773 inherited = ENV['UNICORN_FD'].to_s.split(/,/).map do |fd|
774 io = Socket.for_fd(fd.to_i)
775 set_server_sockopt(io, listener_opts[sock_name(io)])
776 prevent_autoclose(io)
777 logger.info "inherited addr=#{sock_name(io)} fd=#{fd}"
781 config_listeners = config[:listeners].dup
782 LISTENERS.replace(inherited)
784 # we start out with generic Socket objects that get cast to either
785 # Kgio::TCPServer or Kgio::UNIXServer objects; but since the Socket
786 # objects share the same OS-level file descriptor as the higher-level
787 # *Server objects; we need to prevent Socket objects from being
789 config_listeners -= listener_names
790 if config_listeners.empty? && LISTENERS.empty?
791 config_listeners << Unicorn::Const::DEFAULT_LISTEN
792 @init_listeners << Unicorn::Const::DEFAULT_LISTEN
793 START_CTX[:argv] << "-l#{Unicorn::Const::DEFAULT_LISTEN}"
795 NEW_LISTENERS.replace(config_listeners)
798 # call only after calling inherit_listeners!
799 # This binds any listeners we did NOT inherit from the parent
800 def bind_new_listeners!
801 NEW_LISTENERS.each { |addr| listen(addr) }
802 raise ArgumentError, "no listeners" if LISTENERS.empty?