1 # ----------------------------------------------------------------
2 # Copyright (C) 2010 Equinox Software, Inc.
3 # Bill Erickson <erickson@esilibrary.com>
5 # This program is free software; you can redistribute it and/or
6 # modify it under the terms of the GNU General Public License
7 # as published by the Free Software Foundation; either version 2
8 # of the License, or (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
14 # ----------------------------------------------------------------
15 package OpenSRF::Server;
18 use OpenSRF::Transport;
19 use OpenSRF::Application;
20 use OpenSRF::Utils::Config;
21 use OpenSRF::Transport::PeerHandle;
22 use OpenSRF::Utils::SettingsClient;
23 use OpenSRF::Utils::Logger qw($logger);
24 use OpenSRF::Transport::SlimJabber::Client;
26 use POSIX qw/:sys_wait_h :errno_h/;
27 use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
28 use Time::HiRes qw/usleep/;
31 our $chatty = 1; # disable for production
33 use constant STATUS_PIPE_DATA_SIZE => 12;
34 use constant WRITE_PIPE_DATA_SIZE => 12;
37 my($class, $service, %args) = @_;
38 my $self = bless(\%args, $class);
40 $self->{service} = $service; # service name
41 $self->{num_children} = 0; # number of child processes
42 $self->{osrf_handle} = undef; # xmpp handle
43 $self->{routers} = []; # list of registered routers
44 $self->{active_list} = []; # list of active children
45 $self->{idle_list} = []; # list of idle children
46 $self->{sighup_pending} = [];
47 $self->{pid_map} = {}; # map of child pid to child for cleaner access
48 $self->{sig_pipe} = 0; # true if last syswrite failed
50 $self->{stderr_log} = $self->{stderr_log_path} . "/${service}_stderr.log"
51 if $self->{stderr_log_path};
53 $self->{min_spare_children} ||= 0;
55 $self->{max_spare_children} = $self->{min_spare_children} + 1 if
56 $self->{max_spare_children} and
57 $self->{max_spare_children} <= $self->{min_spare_children};
62 # ----------------------------------------------------------------
63 # Disconnects from routers and waits for child processes to exit.
64 # ----------------------------------------------------------------
70 $logger->info("server: shutting down and cleaning up...");
73 $self->unregister_routers;
76 # graceful shutdown waits for all active
77 # children to complete their in-process tasks.
79 while (@{$self->{active_list}}) {
80 $logger->info("server: graceful shutdown with ".
81 @{$self->{active_list}}." active children...");
83 # block until a child is becomes available
84 $self->check_status(1);
86 $logger->info("server: all clear for graceful shutdown");
89 # don't get sidetracked by signals while we're cleaning up.
90 # it could result in unexpected behavior with list traversal
91 $SIG{CHLD} = 'IGNORE';
93 # terminate the child processes
94 $self->kill_child($_) for
95 (@{$self->{idle_list}}, @{$self->{active_list}});
97 $self->{osrf_handle}->disconnect;
99 # clean up our dead children
100 $self->reap_children(1);
102 exit(0) unless $no_exit;
105 # ----------------------------------------------------------------
106 # SIGHUP handler. Kill all idle children. Copy list of active
107 # children into sighup_pending list for later cleanup.
108 # ----------------------------------------------------------------
111 $logger->info("server: caught SIGHUP; reloading children");
113 # reload the opensrf config
114 # note: calling ::Config->load() results in ever-growing
115 # package names, which eventually causes an exception
116 OpenSRF::Utils::Config->current->_load(
118 config_file => OpenSRF::Utils::Config->current->FILE
121 # force-reload the logger config
122 OpenSRF::Utils::Logger::set_config(1);
124 # copy active list into pending list for later cleanup
125 $self->{sighup_pending} = [ @{$self->{active_list}} ];
127 # idle_list will be modified as children are reaped.
128 my @idle = @{$self->{idle_list}};
130 # idle children are the reaper's plaything
131 $self->kill_child($_) for @idle;
134 # ----------------------------------------------------------------
135 # Waits on the jabber socket for inbound data from the router.
136 # Each new message is passed off to a child process for handling.
137 # At regular intervals, wake up for min/max spare child maintenance
138 # ----------------------------------------------------------------
142 $logger->set_service($self->{service});
144 $SIG{$_} = sub { $self->cleanup; } for (qw/INT QUIT/);
145 $SIG{TERM} = sub { $self->cleanup(0, 1); };
146 $SIG{CHLD} = sub { $self->reap_children(); };
147 $SIG{HUP} = sub { $self->handle_sighup(); };
148 $SIG{USR1} = sub { $self->unregister_routers; };
149 $SIG{USR2} = sub { $self->register_routers; };
151 $self->spawn_children;
152 $self->build_osrf_handle;
153 $self->register_routers;
160 $self->{child_died} = 0;
162 my $msg = $self->{osrf_handle}->process($wait_time);
164 # we woke up for any reason, reset the wait time to allow
165 # for idle maintenance as necessary
170 if ($msg->type and $msg->type eq 'error') {
171 $logger->info("server: Listener received an XMPP error ".
172 "message. Likely a bounced message. sender=".$msg->from);
174 } elsif(my $child = pop(@{$self->{idle_list}})) {
176 # we have an idle child to handle the request
177 $chatty and $logger->internal("server: passing request to idle child $child");
178 push(@{$self->{active_list}}, $child);
179 $self->write_child($child, $msg);
181 } elsif($self->{num_children} < $self->{max_children}) {
183 # spawning a child to handle the request
184 $chatty and $logger->internal("server: spawning child to handle request");
185 $self->write_child($self->spawn_child(1), $msg);
188 $logger->warn("server: no children available, waiting... consider increasing " .
189 "max_children for this application higher than $self->{max_children} ".
190 "in the OpenSRF configuration if this message occurs frequently");
191 $self->check_status(1); # block until child is available
193 my $child = pop(@{$self->{idle_list}});
194 push(@{$self->{active_list}}, $child);
195 $self->write_child($child, $msg);
200 # don't perform idle maint immediately when woken by SIGCHLD
201 unless($self->{child_died}) {
203 # when we hit equilibrium, there's no need for regular
204 # maintenance, so set wait_time to 'forever'
206 !$self->perform_idle_maintenance and # no maintenance performed this time
207 @{$self->{active_list}} == 0; # no active children
213 # ----------------------------------------------------------------
214 # Launch a new spare child or kill an extra spare child. To
215 # prevent large-scale spawning or die-offs, spawn or kill only
216 # 1 process per idle maintenance loop.
217 # Returns true if any idle maintenance occurred, 0 otherwise
218 # ----------------------------------------------------------------
219 sub perform_idle_maintenance {
222 $chatty and $logger->internal(
224 "server: %d idle, %d active, %d min_spare, %d max_spare in idle maintenance",
225 scalar(@{$self->{idle_list}}),
226 scalar(@{$self->{active_list}}),
227 $self->{min_spare_children},
228 $self->{max_spare_children}
232 # spawn 1 spare child per maintenance loop if necessary
233 if( $self->{min_spare_children} and
234 $self->{num_children} < $self->{max_children} and
235 scalar(@{$self->{idle_list}}) < $self->{min_spare_children} ) {
237 $chatty and $logger->internal("server: spawning spare child");
241 # kill 1 excess spare child per maintenance loop if necessary
242 } elsif($self->{max_spare_children} and
243 $self->{num_children} > $self->{min_children} and
244 scalar(@{$self->{idle_list}}) > $self->{max_spare_children} ) {
246 $chatty and $logger->internal("server: killing spare child");
256 my $child = shift || pop(@{$self->{idle_list}}) or return;
257 $chatty and $logger->internal("server: killing child $child");
258 kill('TERM', $child->{pid});
261 # ----------------------------------------------------------------
262 # Jabber connection inbound message arrive on.
263 # ----------------------------------------------------------------
264 sub build_osrf_handle {
267 my $conf = OpenSRF::Utils::Config->current;
268 my $username = $conf->bootstrap->username;
269 my $password = $conf->bootstrap->passwd;
270 my $domain = $conf->bootstrap->domain;
271 my $port = $conf->bootstrap->port;
272 my $resource = $self->{service} . '_listener_' . $conf->env->hostname;
274 $logger->debug("server: inbound connecting as $username\@$domain/$resource on port $port");
276 $self->{osrf_handle} =
277 OpenSRF::Transport::SlimJabber::Client->new(
278 username => $username,
279 resource => $resource,
280 password => $password,
285 $self->{osrf_handle}->initialize;
289 # ----------------------------------------------------------------
290 # Sends request data to a child process
291 # ----------------------------------------------------------------
293 my($self, $child, $msg) = @_;
294 my $xml = encode_utf8(decode_utf8($msg->to_xml));
296 # tell the child how much data to expect, minus the header
298 {use bytes; $write_size = length($xml)}
299 $write_size = sprintf("%*s", WRITE_PIPE_DATA_SIZE, $write_size);
303 $self->{sig_pipe} = 0;
304 local $SIG{'PIPE'} = sub { $self->{sig_pipe} = 1; };
306 # In rare cases a child can die between creation and first
307 # write, typically a result of a jabber connect error. Before
308 # sending data to each child, confirm it's still alive. If it's
309 # not, log the error and drop the message to prevent the parent
310 # process from dying.
311 # When a child dies, all of its attributes are deleted,
312 # so the lack of a pid means the child is dead.
313 if (!$child->{pid}) {
314 $logger->error("server: child is dead in write_child(). ".
315 "unable to send message: $xml");
316 return; # avoid syswrite crash
319 # send message to child data pipe
320 syswrite($child->{pipe_to_child}, $write_size . $xml);
322 last unless $self->{sig_pipe};
323 $logger->error("server: got SIGPIPE writing to $child, retrying...");
324 usleep(50000); # 50 msec
327 $logger->error("server: unable to send request message to child $child") if $self->{sig_pipe};
330 # ----------------------------------------------------------------
331 # Checks to see if any child process has reported its availability
332 # In blocking mode, blocks until a child has reported.
333 # ----------------------------------------------------------------
335 my($self, $block) = @_;
337 return unless @{$self->{active_list}};
343 # if can_read or sysread is interrupted while bloking, go back and
344 # wait again until we have at least 1 free child
346 # refresh the read_set handles in case we lost a child in the previous iteration
347 my $read_set = IO::Select->new;
348 $read_set->add($_->{pipe_to_child}) for @{$self->{active_list}};
350 if(my @handles = $read_set->can_read(($block) ? undef : 0)) {
352 for my $pipe (@handles) {
353 sysread($pipe, $pid, STATUS_PIPE_DATA_SIZE) or next;
354 push(@pids, int($pid));
358 last unless $block and !@pids;
363 $chatty and $logger->internal("server: ".scalar(@pids)." children reporting for duty: (@pids)");
368 # move the children from the active list to the idle list
369 for my $proc (@{$self->{active_list}}) {
370 if(grep { $_ == $proc->{pid} } @pids) {
371 push(@{$self->{idle_list}}, $proc);
373 push(@new_actives, $proc);
377 $self->{active_list} = [@new_actives];
379 $chatty and $logger->internal(sprintf(
380 "server: %d idle and %d active children after status update",
381 scalar(@{$self->{idle_list}}), scalar(@{$self->{active_list}})));
383 # some children just went from active to idle. let's see
384 # if any of them need to be killed from a previous sighup.
386 for my $child (@{$self->{sighup_pending}}) {
387 if (grep {$_ == $child->{pid}} @pids) {
389 $chatty and $logger->internal(
390 "server: killing previously-active ".
391 "child after receiving SIGHUP: $child");
393 # remove the pending child
394 $self->{sighup_pending} = [
395 grep {$_->{pid} != $child->{pid}}
396 @{$self->{sighup_pending}}
399 # kill the pending child
400 $self->kill_child($child)
405 # ----------------------------------------------------------------
406 # Cleans up any child processes that have exited.
407 # In shutdown mode, block until all children have washed ashore
408 # ----------------------------------------------------------------
410 my($self, $shutdown) = @_;
411 $self->{child_died} = 1;
415 my $pid = waitpid(-1, ($shutdown) ? 0 : WNOHANG);
418 $chatty and $logger->internal("server: reaping child $pid");
420 my $child = $self->{pid_map}->{$pid};
422 close($child->{pipe_to_parent});
423 close($child->{pipe_to_child});
425 $self->{active_list} = [ grep { $_->{pid} != $pid } @{$self->{active_list}} ];
426 $self->{idle_list} = [ grep { $_->{pid} != $pid } @{$self->{idle_list}} ];
428 $self->{num_children}--;
429 delete $self->{pid_map}->{$pid};
430 delete $child->{$_} for keys %$child; # destroy with a vengeance
433 $self->spawn_children unless $shutdown;
435 $chatty and $logger->internal(sprintf(
436 "server: %d idle and %d active children after reap_children",
437 scalar(@{$self->{idle_list}}), scalar(@{$self->{active_list}})));
440 # ----------------------------------------------------------------
441 # Spawn up to max_children processes
442 # ----------------------------------------------------------------
445 $self->spawn_child while $self->{num_children} < $self->{min_children};
448 # ----------------------------------------------------------------
449 # Spawns a new child. If $active is set, the child goes directly
450 # into the active_list.
451 # ----------------------------------------------------------------
453 my($self, $active) = @_;
455 my $child = OpenSRF::Server::Child->new($self);
457 # socket for sending message data to the child
459 $child->{pipe_to_child},
460 $child->{pipe_to_parent},
461 AF_UNIX, SOCK_STREAM, PF_UNSPEC)) {
462 $logger->error("server: error creating data socketpair: $!");
466 $child->{pipe_to_child}->autoflush(1);
467 $child->{pipe_to_parent}->autoflush(1);
469 $child->{pid} = fork();
471 if($child->{pid}) { # parent process
472 $self->{num_children}++;
473 $self->{pid_map}->{$child->{pid}} = $child;
476 push(@{$self->{active_list}}, $child);
478 push(@{$self->{idle_list}}, $child);
481 $chatty and $logger->internal("server: server spawned child $child with ".$self->{num_children}." total children");
485 } else { # child process
487 # recover default handling for any signal whose handler
488 # may have been adopted from the parent process.
489 $SIG{$_} = 'DEFAULT' for qw/TERM INT QUIT HUP CHLD USR1 USR2/;
491 if($self->{stderr_log}) {
493 $chatty and $logger->internal("server: redirecting STDERR to " . $self->{stderr_log});
496 unless( open(STDERR, '>>' . $self->{stderr_log}) ) {
497 $logger->error("server: unable to open STDERR log file: " . $self->{stderr_log} . " : $@");
498 open STDERR, '>/dev/null'; # send it back to /dev/null
506 OpenSRF::Transport::PeerHandle->retrieve->disconnect;
508 $logger->error("server: child process died: $@") if $@;
513 # ----------------------------------------------------------------
514 # Sends the register command to the configured routers
515 # ----------------------------------------------------------------
516 sub register_routers {
519 my $conf = OpenSRF::Utils::Config->current;
520 my $routers = $conf->bootstrap->routers;
521 my $router_name = $conf->bootstrap->router_name;
524 for my $router (@$routers) {
527 if( !$router->{services} ||
528 !$router->{services}->{service} ||
530 ref($router->{services}->{service}) eq 'ARRAY' and
531 grep { $_ eq $self->{service} } @{$router->{services}->{service}}
532 ) || $router->{services}->{service} eq $self->{service}) {
534 my $name = $router->{name};
535 my $domain = $router->{domain};
536 push(@targets, "$name\@$domain/router");
540 push(@targets, "$router_name\@$router/router");
545 $logger->info("server: registering with router $_");
546 $self->{osrf_handle}->send(
548 body => 'registering',
549 router_command => 'register',
550 router_class => $self->{service}
554 $self->{routers} = \@targets;
557 # ----------------------------------------------------------------
558 # Sends the unregister command to any routers we have registered
560 # ----------------------------------------------------------------
561 sub unregister_routers {
563 return unless $self->{osrf_handle}->tcp_connected;
565 for my $router (@{$self->{routers}}) {
566 $logger->info("server: disconnecting from router $router");
567 $self->{osrf_handle}->send(
569 body => "unregistering",
570 router_command => "unregister",
571 router_class => $self->{service}
577 package OpenSRF::Server::Child;
580 use OpenSRF::Transport;
581 use OpenSRF::Application;
582 use OpenSRF::Transport::PeerHandle;
583 use OpenSRF::Transport::SlimJabber::XMPPMessage;
584 use OpenSRF::Utils::Logger qw($logger);
585 use OpenSRF::DomainObject::oilsResponse qw/:status/;
586 use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
587 use Time::HiRes qw(time usleep);
588 use POSIX qw/:sys_wait_h :errno_h/;
590 use overload '""' => sub { return '[' . shift()->{pid} . ']'; };
593 my($class, $parent) = @_;
594 my $self = bless({}, $class);
595 $self->{pid} = 0; # my process ID
596 $self->{parent} = $parent; # Controller parent process
597 $self->{num_requests} = 0; # total serviced requests
598 $self->{sig_pipe} = 0; # true if last syswrite failed
604 my $flags = fcntl($fh, F_GETFL, 0);
605 fcntl($fh, F_SETFL, $flags | O_NONBLOCK);
610 my $flags = fcntl($fh, F_GETFL, 0);
611 $flags &= ~O_NONBLOCK;
612 fcntl($fh, F_SETFL, $flags);
615 # ----------------------------------------------------------------
616 # Connects to Jabber and runs the application child_init
617 # ----------------------------------------------------------------
620 my $service = $self->{parent}->{service};
621 $0 = "OpenSRF Drone [$service]";
622 OpenSRF::Transport::PeerHandle->construct($service);
623 OpenSRF::Application->application_implementation->child_init
624 if (OpenSRF::Application->application_implementation->can('child_init'));
627 # ----------------------------------------------------------------
628 # Waits for messages from the parent process, handles the message,
629 # then goes into the keepalive loop if this is a stateful session.
630 # When max_requests is hit, the process exits.
631 # ----------------------------------------------------------------
634 my $network = OpenSRF::Transport::PeerHandle->retrieve;
636 # main child run loop. Ends when this child hits max requests.
639 my $data = $self->wait_for_request or next;
641 # Update process name to show activity
645 # Discard extraneous data from the jabber socket
646 if(!$network->flush_socket()) {
647 $logger->error("server: network disconnected! child dropping request and exiting: $data");
651 my $session = OpenSRF::Transport->handler(
652 $self->{parent}->{service},
653 OpenSRF::Transport::SlimJabber::XMPPMessage->new(xml => $data)
656 $self->keepalive_loop($session);
658 last if ++$self->{num_requests} == $self->{parent}->{max_requests};
660 # Tell the parent process we are available to process requests
663 # Repair process name
667 $chatty and $logger->internal("server: child process shutting down after reaching max_requests");
669 OpenSRF::Application->application_implementation->child_exit
670 if (OpenSRF::Application->application_implementation->can('child_exit'));
673 # ----------------------------------------------------------------
674 # waits for a request data on the parent pipe and returns it.
675 # ----------------------------------------------------------------
676 sub wait_for_request {
679 my $data = ''; # final request data
680 my $buf_size = 4096; # default linux pipe_buf (atomic window, not total size)
681 my $read_pipe = $self->{pipe_to_parent};
682 my $bytes_needed; # size of the data we are about to receive
683 my $bytes_recvd; # number of bytes read so far
684 my $first_read = 1; # true for first loop iteration
689 # wait for some data to start arriving
690 my $read_set = IO::Select->new;
691 $read_set->add($read_pipe);
694 # if can_read is interrupted while blocking,
695 # go back and wait again until it succeeds.
696 last if $read_set->can_read;
699 # parent started writing, let's start reading
700 $self->set_nonblock($read_pipe);
703 # read all of the available data
706 my $nbytes = sysread($self->{pipe_to_parent}, $buf, $buf_size);
708 unless(defined $nbytes) {
710 $logger->error("server: error reading data from parent: $!. ".
711 "bytes_needed=$bytes_needed; bytes_recvd=$bytes_recvd; data=$data");
717 last if $nbytes <= 0; # no more data available for reading
719 $bytes_recvd += $nbytes;
723 $self->set_block($self->{pipe_to_parent});
724 return undef if $read_error;
726 # extract the data size and remove the header from the final data
728 my $wps_size = OpenSRF::Server::WRITE_PIPE_DATA_SIZE;
729 $bytes_needed = int(substr($data, 0, $wps_size)) + $wps_size;
730 $data = substr($data, $wps_size);
735 if ($bytes_recvd == $bytes_needed) {
736 # we've read all the data. Nothing left to do
740 $logger->info("server: child process read all available pipe data. ".
741 "waiting for more data from parent. bytes_needed=$bytes_needed; bytes_recvd=$bytes_recvd");
748 # ----------------------------------------------------------------
749 # If this is a stateful opensrf session, wait up to $keepalive
750 # seconds for subsequent requests from the client
751 # ----------------------------------------------------------------
753 my($self, $session) = @_;
754 my $keepalive = $self->{parent}->{keepalive};
756 while($session->state and $session->state == $session->CONNECTED) {
758 unless( $session->queue_wait($keepalive) ) {
760 # client failed to disconnect before timeout
761 $logger->info("server: no request was received in $keepalive seconds, exiting stateful session");
763 my $res = OpenSRF::DomainObject::oilsConnectStatus->new(
764 status => "Disconnected on timeout",
765 statusCode => STATUS_TIMEOUT
768 $session->status($res);
769 $session->state($session->DISCONNECTED);
774 $chatty and $logger->internal("server: child done with request(s)");
778 # ----------------------------------------------------------------
779 # Report our availability to our parent process
780 # ----------------------------------------------------------------
786 $self->{sig_pipe} = 0;
787 local $SIG{'PIPE'} = sub { $self->{sig_pipe} = 1; };
790 $self->{pipe_to_parent},
791 sprintf("%*s", OpenSRF::Server::STATUS_PIPE_DATA_SIZE, $self->{pid})
794 last unless $self->{sig_pipe};
795 $logger->error("server: $self got SIGPIPE writing status to parent, retrying...");
796 usleep(50000); # 50 msec
799 $logger->error("server: $self unable to send status to parent") if $self->{sig_pipe};