File:
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loncnew
Revision
1.100:
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Fri Jun 17 17:41:37 2011 UTC (12 years, 10 months ago) by
raeburn
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CVS tags:
version_2_11_X,
version_2_11_2_uiuc,
version_2_11_2_msu,
version_2_11_2_educog,
version_2_11_2,
version_2_11_1,
version_2_11_0_RC3,
version_2_11_0_RC2,
version_2_11_0_RC1,
version_2_11_0,
version_2_10_X,
version_2_10_1,
loncapaMITrelate_1,
language_hyphenation_merge,
language_hyphenation,
HEAD,
BZ4492-merge,
BZ4492-feature_horizontal_radioresponse,
BZ4492-feature_Support_horizontal_radioresponse,
BZ4492-Support_horizontal_radioresponse
- Eliminate lone single quotes in POD which could cause problems with
syntax highlighting for some editors.
1: #!/usr/bin/perl
2: # The LearningOnline Network with CAPA
3: # lonc maintains the connections to remote computers
4: #
5: # $Id: loncnew,v 1.100 2011/06/17 17:41:37 raeburn Exp $
6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
10: ## LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: #
29: # new lonc handles n request out over m connections to londs.
30: # This module is based on the Event class.
31: # Development iterations:
32: # - Setup basic event loop. (done)
33: # - Add timer dispatch. (done)
34: # - Add ability to accept lonc UNIX domain sockets. (done)
35: # - Add ability to create/negotiate lond connections (done).
36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
38: # - Add logging/status monitoring. (done)
39: # - Add Signal handling - HUP restarts. USR1 status report. (done)
40: # - Add Configuration file I/O (done).
41: # - Add management/status request interface. (done)
42: # - Add deferred request capability. (done)
43: # - Detect transmission timeouts. (done)
44: #
45:
46: use strict;
47: use lib "/home/httpd/lib/perl/";
48: use Event qw(:DEFAULT );
49: use POSIX qw(:signal_h);
50: use POSIX;
51: use IO::Socket;
52: use IO::Socket::INET;
53: use IO::Socket::UNIX;
54: use IO::File;
55: use IO::Handle;
56: use Socket;
57: use Crypt::IDEA;
58: use LONCAPA::Queue;
59: use LONCAPA::Stack;
60: use LONCAPA::LondConnection;
61: use LONCAPA::LondTransaction;
62: use LONCAPA::Configuration;
63: use Fcntl qw(:flock);
64:
65:
66: # Read the httpd configuration file to get perl variables
67: # normally set in apache modules:
68:
69: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
70: my %perlvar = %{$perlvarref};
71:
72: #
73: # parent and shared variables.
74:
75: my %ChildPid; # by pid -> host.
76: my %ChildHost; # by host.
77: my %listening_to; # Socket->host table for who the parent
78: # is listening to.
79: my %parent_dispatchers; # host-> listener watcher events.
80:
81: my %parent_handlers; # Parent signal handlers...
82:
83: my $MaxConnectionCount = 10; # Will get from config later.
84: my $ClientConnection = 0; # Uniquifier for client events.
85:
86: my $DebugLevel = 0;
87: my $NextDebugLevel= 2; # So Sigint can toggle this.
88: my $IdleTimeout= 5*60; # Seconds to wait prior to pruning connections.
89:
90: my $LogTransactions = 0; # When True, all transactions/replies get logged.
91: my $executable = $0; # Get the full path to me.
92:
93: #
94: # The variables below are only used by the child processes.
95: #
96: my $RemoteHost; # Name of host child is talking to.
97: my $RemoteHostId; # default lonid of host child is talking to.
98: my @all_host_ids;
99: my $UnixSocketDir= $perlvar{'lonSockDir'};
100: my $IdleConnections = Stack->new(); # Set of idle connections
101: my %ActiveConnections; # Connections to the remote lond.
102: my %ActiveTransactions; # LondTransactions in flight.
103: my %ActiveClients; # Serial numbers of active clients by socket.
104: my $WorkQueue = Queue->new(); # Queue of pending transactions.
105: my $ConnectionCount = 0;
106: my $IdleSeconds = 0; # Number of seconds idle.
107: my $Status = ""; # Current status string.
108: my $RecentLogEntry = "";
109: my $ConnectionRetries=5; # Number of connection retries allowed.
110: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
111: my $LondVersion = "unknown"; # Version of lond we talk with.
112: my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
113: my $LondConnecting = 0; # True when a connection is being built.
114:
115:
116:
117: my $I_am_child = 0; # True if this is the child process.
118:
119: #
120: # The hash below gives the HTML format for log messages
121: # given a severity.
122: #
123: my %LogFormats;
124:
125: $LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
126: $LogFormats{"SUCCESS"} = "<font color='green'>SUCCESS: %s</font>";
127: $LogFormats{"INFO"} = "<font color='yellow'>INFO: %s</font>";
128: $LogFormats{"WARNING"} = "<font color='blue'>WARNING: %s</font>";
129: $LogFormats{"DEFAULT"} = " %s ";
130:
131:
132: # UpdateStatus;
133: # Update the idle status display to show how many connections
134: # are left, retries and other stuff.
135: #
136: sub UpdateStatus {
137: if ($ConnectionRetriesLeft > 0) {
138: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
139: ." Retries remaining: ".$ConnectionRetriesLeft
140: ." ($KeyMode)");
141: } else {
142: ShowStatus(GetServerHost()." >> DEAD <<");
143: }
144: }
145:
146:
147: =pod
148:
149: =head2 LogPerm
150:
151: Makes an entry into the permanent log file.
152:
153: =cut
154:
155: sub LogPerm {
156: my $message=shift;
157: my $execdir=$perlvar{'lonDaemons'};
158: my $now=time;
159: my $local=localtime($now);
160: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
161: chomp($message);
162: print $fh "$now:$message:$local\n";
163: }
164:
165: =pod
166:
167: =head2 Log
168:
169: Logs a message to the log file.
170: Parameters:
171:
172: =item severity
173:
174: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
175: format string used to format the message. if the severity is
176: not a defined severity the Default format string is used.
177:
178: =item message
179:
180: The base message. In addtion to the format string, the message
181: will be appended to a string containing the name of our remote
182: host and the time will be formatted into the message.
183:
184: =cut
185:
186: sub Log {
187:
188: my ($severity, $message) = @_;
189:
190: if(!$LogFormats{$severity}) {
191: $severity = "DEFAULT";
192: }
193:
194: my $format = $LogFormats{$severity};
195:
196: # Put the window dressing in in front of the message format:
197:
198: my $now = time;
199: my $local = localtime($now);
200: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
201: $finalformat = $finalformat.$format."\n";
202:
203: # open the file and put the result.
204:
205: my $execdir = $perlvar{'lonDaemons'};
206: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
207: my $msg = sprintf($finalformat, $message);
208: $RecentLogEntry = $msg;
209: print $fh $msg;
210:
211:
212: }
213:
214:
215: =pod
216:
217: =head2 GetPeerName
218:
219: Returns the name of the host that a socket object is connected to.
220:
221: =cut
222:
223: sub GetPeername {
224:
225:
226: my ($connection, $AdrFamily) = @_;
227:
228: my $peer = $connection->peername();
229: my $peerport;
230: my $peerip;
231: if($AdrFamily == AF_INET) {
232: ($peerport, $peerip) = sockaddr_in($peer);
233: my $peername = gethostbyaddr($peerip, $AdrFamily);
234: return $peername;
235: } elsif ($AdrFamily == AF_UNIX) {
236: my $peerfile;
237: ($peerfile) = sockaddr_un($peer);
238: return $peerfile;
239: }
240: }
241: =pod
242:
243: =head2 Debug
244:
245: Invoked to issue a debug message.
246:
247: =cut
248:
249: sub Debug {
250:
251: my ($level, $message) = @_;
252:
253: if ($level <= $DebugLevel) {
254: Log("INFO", "-Debug- $message host = $RemoteHost");
255: }
256: }
257:
258: sub SocketDump {
259:
260: my ($level, $socket) = @_;
261:
262: if($level <= $DebugLevel) {
263: $socket->Dump(-1); # Ensure it will get dumped.
264: }
265: }
266:
267: =pod
268:
269: =head2 ShowStatus
270:
271: Place some text as our pid status.
272: and as what we return in a SIGUSR1
273:
274: =cut
275:
276: sub ShowStatus {
277: my $state = shift;
278: my $now = time;
279: my $local = localtime($now);
280: $Status = $local.": ".$state;
281: $0='lonc: '.$state.' '.$local;
282: }
283:
284: =pod
285:
286: =head2 SocketTimeout
287:
288: Called when an action on the socket times out. The socket is
289: destroyed and any active transaction is failed.
290:
291:
292: =cut
293:
294: sub SocketTimeout {
295: my $Socket = shift;
296: Log("WARNING", "A socket timeout was detected");
297: Debug(5, " SocketTimeout called: ");
298: $Socket->Dump(0);
299: if(exists($ActiveTransactions{$Socket})) {
300: FailTransaction($ActiveTransactions{$Socket});
301: }
302: KillSocket($Socket); # A transaction timeout also counts as
303: # a connection failure:
304: $ConnectionRetriesLeft--;
305: if($ConnectionRetriesLeft <= 0) {
306: Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
307: $LondConnecting = 0;
308: }
309:
310: }
311:
312: #
313: # This function should be called by the child in all cases where it must
314: # exit. The child process must create a lock file for the AF_UNIX socket
315: # in order to prevent connection requests from lonnet in the time between
316: # process exit and the parent picking up the listen again.
317: #
318: # Parameters:
319: # exit_code - Exit status value, however see the next parameter.
320: # message - If this optional parameter is supplied, the exit
321: # is via a die with this message.
322: #
323: sub child_exit {
324: my ($exit_code, $message) = @_;
325:
326: # Regardless of how we exit, we may need to do the lock thing:
327:
328: #
329: # Create a lock file since there will be a time window
330: # between our exit and the parent's picking up the listen
331: # during which no listens will be done on the
332: # lonnet client socket.
333: #
334: my $lock_file = &GetLoncSocketPath().".lock";
335: open(LOCK,">$lock_file");
336: print LOCK "Contents not important";
337: close(LOCK);
338: unlink(&GetLoncSocketPath());
339:
340: if ($message) {
341: die($message);
342: } else {
343: exit($exit_code);
344: }
345: }
346: #----------------------------- Timer management ------------------------
347:
348: =pod
349:
350: =head2 Tick
351:
352: Invoked each timer tick.
353:
354: =cut
355:
356:
357: sub Tick {
358: my ($Event) = @_;
359: my $clock_watcher = $Event->w;
360:
361: my $client;
362: UpdateStatus();
363:
364: # Is it time to prune connection count:
365:
366:
367: if($IdleConnections->Count() &&
368: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
369: $IdleSeconds++;
370: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
371: my $Socket = $IdleConnections->pop();
372: KillSocket($Socket);
373: $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
374: UpdateStatus();
375: if(($ConnectionCount == 0)) {
376: &child_exit(0);
377:
378: }
379: }
380: } else {
381: $IdleSeconds = 0; # Reset idle count if not idle.
382: }
383: #
384: # For each inflight transaction, tick down its timeout counter.
385: #
386:
387: foreach my $item (keys %ActiveConnections) {
388: my $State = $ActiveConnections{$item}->data->GetState();
389: if ($State ne 'Idle') {
390: Debug(5,"Ticking Socket $State $item");
391: $ActiveConnections{$item}->data->Tick();
392: }
393: }
394: # Do we have work in the queue, but no connections to service them?
395: # If so, try to make some new connections to get things going again.
396: #
397: # Note this code is dead now...
398: #
399: my $Requests = $WorkQueue->Count();
400: if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
401: if ($ConnectionRetriesLeft > 0) {
402: Debug(5,"Work but no connections, Make a new one");
403: my $success;
404: $success = &MakeLondConnection;
405: if($success == 0) { # All connections failed:
406: Debug(5,"Work in queue failed to make any connectiouns\n");
407: EmptyQueue(); # Fail pending transactions with con_lost.
408: CloseAllLondConnections(); # Should all be closed but....
409: }
410: } else {
411: $LondConnecting = 0;
412: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
413: Debug(5,"Work in queue, but gave up on connections..flushing\n");
414: EmptyQueue(); # Connections can't be established.
415: CloseAllLondConnections(); # Should all already be closed but...
416: }
417:
418: }
419: if ($ConnectionCount == 0) {
420: $KeyMode = "";
421: $clock_watcher->cancel();
422: }
423: &UpdateStatus();
424: }
425:
426: =pod
427:
428: =head2 SetupTimer
429:
430: Sets up a 1 per sec recurring timer event. The event handler is used to:
431:
432: =item
433:
434: Trigger timeouts on communications along active sockets.
435:
436: =item
437:
438: Trigger disconnections of idle sockets.
439:
440: =cut
441:
442: sub SetupTimer {
443: Debug(6, "SetupTimer");
444: Event->timer(interval => 1, cb => \&Tick,
445: hard => 1);
446: }
447:
448: =pod
449:
450: =head2 ServerToIdle
451:
452: This function is called when a connection to the server is
453: ready for more work.
454:
455: If there is work in the Work queue the top element is dequeued
456: and the connection will start to work on it. If the work queue is
457: empty, the connection is pushed on the idle connection stack where
458: it will either get another work unit, or alternatively, if it sits there
459: long enough, it will be shut down and released.
460:
461: =cut
462:
463: sub ServerToIdle {
464: my $Socket = shift; # Get the socket.
465: $KeyMode = $Socket->{AuthenticationMode};
466: delete($ActiveTransactions{$Socket}); # Server has no transaction
467:
468: &Debug(5, "Server to idle");
469:
470: # If there's work to do, start the transaction:
471:
472: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
473: if ($reqdata ne undef) {
474: Debug(5, "Queue gave request data: ".$reqdata->getRequest());
475: &StartRequest($Socket, $reqdata);
476:
477: } else {
478:
479: # There's no work waiting, so push the server to idle list.
480: &Debug(5, "No new work requests, server connection going idle");
481: $IdleConnections->push($Socket);
482: }
483: }
484:
485: =pod
486:
487: =head2 ClientWritable
488:
489: Event callback for when a client socket is writable.
490:
491: This callback is established when a transaction response is
492: available from lond. The response is forwarded to the unix socket
493: as it becomes writable in this sub.
494:
495: Parameters:
496:
497: =item Event
498:
499: The event that has been triggered. Event->w->data is
500: the data and Event->w->fd is the socket to write.
501:
502: =cut
503:
504: sub ClientWritable {
505: my $Event = shift;
506: my $Watcher = $Event->w;
507: if (!defined($Watcher)) {
508: &child_exit(-1,'No watcher for event in ClientWritable');
509: }
510: my $Data = $Watcher->data;
511: my $Socket = $Watcher->fd;
512:
513: # Try to send the data:
514:
515: &Debug(6, "ClientWritable writing".$Data);
516: &Debug(9, "Socket is: ".$Socket);
517:
518: if($Socket->connected) {
519: my $result = $Socket->send($Data, 0);
520:
521: # $result undefined: the write failed.
522: # otherwise $result is the number of bytes written.
523: # Remove that preceding string from the data.
524: # If the resulting data is empty, destroy the watcher
525: # and set up a read event handler to accept the next
526: # request.
527:
528: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
529: if($result ne undef) {
530: &Debug(9, "send result was defined");
531: if($result == length($Data)) { # Entire string sent.
532: &Debug(9, "ClientWritable data all written");
533: $Watcher->cancel();
534: #
535: # Set up to read next request from socket:
536:
537: my $descr = sprintf("Connection to lonc client %d",
538: $ActiveClients{$Socket});
539: Event->io(cb => \&ClientRequest,
540: poll => 'r',
541: desc => $descr,
542: data => "",
543: fd => $Socket);
544:
545: } else { # Partial string sent.
546: $Watcher->data(substr($Data, $result));
547: if($result == 0) { # client hung up on us!!
548: # Log("INFO", "lonc pipe client hung up on us!");
549: $Watcher->cancel;
550: $Socket->shutdown(2);
551: $Socket->close();
552: }
553: }
554:
555: } else { # Error of some sort...
556:
557: # Some errnos are possible:
558: my $errno = $!;
559: if($errno == POSIX::EWOULDBLOCK ||
560: $errno == POSIX::EAGAIN ||
561: $errno == POSIX::EINTR) {
562: # No action taken...the socket will be writable firing the event again
563: # which will result in a retry of the write.
564: } else { # Unanticipated errno.
565: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
566: $Watcher->cancel; # Stop the watcher.
567: $Socket->shutdown(2); # Kill connection
568: $Socket->close(); # Close the socket.
569: }
570:
571: }
572: } else {
573: $Watcher->cancel(); # A delayed request...just cancel.
574: return;
575: }
576: }
577:
578: =pod
579:
580: =head2 CompleteTransaction
581:
582: Called when the reply data has been received for a lond
583: transaction. The reply data must now be sent to the
584: ultimate client on the other end of the Unix socket. This is
585: done by setting up a writable event for the socket with the
586: data the reply data.
587:
588: Parameters:
589:
590: =item Socket
591:
592: Socket on which the lond transaction occurred. This is a
593: LondConnection. The data received are in the TransactionReply member.
594:
595: =item Transaction
596:
597: The transaction that is being completed.
598:
599: =cut
600:
601: sub CompleteTransaction {
602: &Debug(5,"Complete transaction");
603:
604: my ($Socket, $Transaction) = @_;
605:
606: if (!$Transaction->isDeferred()) { # Normal transaction
607: my $data = $Socket->GetReply(); # Data to send.
608: if($LogTransactions) {
609: Log("SUCCESS", "Reply from lond: '$data'");
610: }
611: StartClientReply($Transaction, $data);
612: } else { # Delete deferred transaction file.
613: Log("SUCCESS", "A delayed transaction was completed");
614: LogPerm("S:".$Transaction->getClient().":".$Transaction->getRequest());
615: unlink($Transaction->getFile());
616: }
617: }
618:
619: =pod
620:
621: =head1 StartClientReply
622:
623: Initiates a reply to a client where the reply data is a parameter.
624:
625: =head2 parameters:
626:
627: =item Transaction
628:
629: The transaction for which we are responding to the client.
630:
631: =item data
632:
633: The data to send to apache client.
634:
635: =cut
636:
637: sub StartClientReply {
638:
639: my ($Transaction, $data) = @_;
640:
641: my $Client = $Transaction->getClient();
642:
643: &Debug(8," Reply was: ".$data);
644: my $Serial = $ActiveClients{$Client};
645: my $desc = sprintf("Connection to lonc client %d",
646: $Serial);
647: Event->io(fd => $Client,
648: poll => "w",
649: desc => $desc,
650: cb => \&ClientWritable,
651: data => $data);
652: }
653:
654: =pod
655:
656: =head2 FailTransaction
657:
658: Finishes a transaction with failure because the associated lond socket
659: disconnected. There are two possibilities:
660: - The transaction is deferred: in which case we just quietly
661: delete the transaction since there is no client connection.
662: - The transaction is 'live' in which case we initiate the sending
663: of "con_lost" to the client.
664:
665: Deleting the transaction means killing it from the %ActiveTransactions hash.
666:
667: Parameters:
668:
669: =item client
670:
671: The LondTransaction we are failing.
672:
673:
674: =cut
675:
676: sub FailTransaction {
677: my $transaction = shift;
678:
679: # If the socket is dead, that's already logged.
680:
681: if ($ConnectionRetriesLeft > 0) {
682: Log("WARNING", "Failing transaction "
683: .$transaction->getLoggableRequest());
684: }
685: Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
686: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
687: my $client = $transaction->getClient();
688: Debug(1," Replying con_lost to ".$transaction->getRequest());
689: StartClientReply($transaction, "con_lost\n");
690: }
691:
692: }
693:
694: =pod
695:
696: =head1 EmptyQueue
697:
698: Fails all items in the work queue with con_lost.
699: Note that each item in the work queue is a transaction.
700:
701: =cut
702:
703: sub EmptyQueue {
704: $ConnectionRetriesLeft--; # Counts as connection failure too.
705: while($WorkQueue->Count()) {
706: my $request = $WorkQueue->dequeue(); # This is a transaction
707: FailTransaction($request);
708: }
709: }
710:
711: =pod
712:
713: =head2 CloseAllLondConnections
714:
715: Close all connections open on lond prior to exit e.g.
716:
717: =cut
718:
719: sub CloseAllLondConnections {
720: foreach my $Socket (keys %ActiveConnections) {
721: if(exists($ActiveTransactions{$Socket})) {
722: FailTransaction($ActiveTransactions{$Socket});
723: }
724: KillSocket($Socket);
725: }
726: }
727:
728: =pod
729:
730: =head2 KillSocket
731:
732: Destroys a socket. This function can be called either when a socket
733: has died of 'natural' causes or because a socket needs to be pruned due to
734: idleness. If the socket has died naturally, if there are no longer any
735: live connections a new connection is created (in case there are transactions
736: in the queue). If the socket has been pruned, it is never re-created.
737:
738: Parameters:
739:
740: =item Socket
741:
742: The socket to kill off.
743:
744: =item Restart
745:
746: non-zero if we are allowed to create a new connection.
747:
748: =cut
749:
750: sub KillSocket {
751: my $Socket = shift;
752:
753: Log("WARNING", "Shutting down a socket");
754: $Socket->Shutdown();
755:
756: # If the socket came from the active connection set,
757: # delete its transaction... note that FailTransaction should
758: # already have been called!!!
759: # otherwise it came from the idle set.
760: #
761:
762: if(exists($ActiveTransactions{$Socket})) {
763: delete ($ActiveTransactions{$Socket});
764: }
765: if(exists($ActiveConnections{$Socket})) {
766: $ActiveConnections{$Socket}->cancel;
767: delete($ActiveConnections{$Socket});
768: $ConnectionCount--;
769: if ($ConnectionCount < 0) { $ConnectionCount = 0; }
770: }
771: # If the connection count has gone to zero and there is work in the
772: # work queue, the work all gets failed with con_lost.
773: #
774: if($ConnectionCount == 0) {
775: $LondConnecting = 0; # No connections so also not connecting.
776: EmptyQueue();
777: CloseAllLondConnections; # Should all already be closed but...
778: }
779: UpdateStatus();
780: }
781:
782: =pod
783:
784: =head2 LondReadable
785:
786: This function is called whenever a lond connection
787: is readable. The action is state dependent:
788:
789: =head3 State=Initialized
790:
791: We are waiting for the challenge, this is a no-op until the
792: state changes.
793:
794: =head3 State=Challenged
795:
796: The challenge has arrived we need to transition to Writable.
797: The connection must echo the challenge back.
798:
799: =head3 State=ChallengeReplied
800:
801: The challenge has been replied to. Then we are receiving the
802: 'ok' from the partner.
803:
804: =head3 State=ReadingVersionString
805:
806: We have requested the lond version and are reading the
807: version back. Upon completion, we'll store the version away
808: for future use(?).
809:
810: =head3 State=HostSet
811:
812: We have selected the domain name of our peer (multhomed hosts)
813: and are getting the reply (presumably ok) back.
814:
815: =head3 State=RequestingKey
816:
817: The ok has been received and we need to send the request for
818: an encryption key. Transition to writable for that.
819:
820: =head3 State=ReceivingKey
821:
822: The the key has been requested, now we are reading the new key.
823:
824: =head3 State=Idle
825:
826: The encryption key has been negotiated or we have finished
827: reading data from the a transaction. If the callback data have
828: a client as well as the socket information, then we are
829: doing a transaction and the data received are relayed to the client
830: before the socket is put on the idle list.
831:
832: =head3 State=SendingRequest
833:
834: I do not think this state can be received here, but if it is,
835: the appropriate thing to do is to transition to writable, and send
836: the request.
837:
838: =head3 State=ReceivingReply
839:
840: We finished sending the request to the server and now transition
841: to readable to receive the reply.
842:
843: The parameter to this function are:
844:
845: The event. Implicit in this is the watcher and its data. The data
846: contain at least the lond connection object and, if a
847: transaction is in progress, the socket attached to the local client.
848:
849: =cut
850:
851: sub LondReadable {
852:
853: my $Event = shift;
854: my $Watcher = $Event->w;
855: my $Socket = $Watcher->data;
856: my $client = undef;
857:
858: &Debug(6,"LondReadable called state = ".$Socket->GetState());
859:
860:
861: my $State = $Socket->GetState(); # All action depends on the state.
862:
863: SocketDump(6, $Socket);
864: my $status = $Socket->Readable();
865:
866: &Debug(2, "Socket->Readable returned: $status");
867:
868: if($status != 0) {
869: # bad return from socket read. Currently this means that
870: # The socket has become disconnected. We fail the transaction.
871:
872: Log("WARNING",
873: "Lond connection lost.");
874: if(exists($ActiveTransactions{$Socket})) {
875: FailTransaction($ActiveTransactions{$Socket});
876: } else {
877: # Socket is connecting and failed... need to mark
878: # no longer connecting.
879:
880: $LondConnecting = 0;
881: }
882: $Watcher->cancel();
883: KillSocket($Socket);
884: $ConnectionRetriesLeft--; # Counts as connection failure
885: return;
886: }
887: SocketDump(6,$Socket);
888:
889: $State = $Socket->GetState(); # Update in case of transition.
890: &Debug(6, "After read, state is ".$State);
891:
892: if($State eq "Initialized") {
893:
894:
895: } elsif ($State eq "ChallengeReceived") {
896: # The challenge must be echoed back; The state machine
897: # in the connection takes care of setting that up. Just
898: # need to transition to writable:
899:
900: $Watcher->cb(\&LondWritable);
901: $Watcher->poll("w");
902:
903: } elsif ($State eq "ChallengeReplied") {
904:
905: } elsif ($State eq "RequestingVersion") {
906: # Need to ask for the version... that is writiability:
907:
908: $Watcher->cb(\&LondWritable);
909: $Watcher->poll("w");
910:
911: } elsif ($State eq "ReadingVersionString") {
912: # Read the rest of the version string...
913: } elsif ($State eq "SetHost") {
914: # Need to request the actual domain get set...
915:
916: $Watcher->cb(\&LondWritable);
917: $Watcher->poll("w");
918: } elsif ($State eq "HostSet") {
919: # Reading the 'ok' from the peer.
920:
921: } elsif ($State eq "RequestingKey") {
922: # The ok was received. Now we need to request the key
923: # That requires us to be writable:
924:
925: $Watcher->cb(\&LondWritable);
926: $Watcher->poll("w");
927:
928: } elsif ($State eq "ReceivingKey") {
929:
930: } elsif ($State eq "Idle") {
931:
932: # This is as good a spot as any to get the peer version
933: # string:
934:
935: if($LondVersion eq "unknown") {
936: $LondVersion = $Socket->PeerVersion();
937: Log("INFO", "Connected to lond version: $LondVersion");
938: }
939: # If necessary, complete a transaction and then go into the
940: # idle queue.
941: # Note that a trasition to idle indicates a live lond
942: # on the other end so reset the connection retries.
943: #
944: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
945: $Watcher->cancel();
946: if(exists($ActiveTransactions{$Socket})) {
947: Debug(5,"Completing transaction!!");
948: CompleteTransaction($Socket,
949: $ActiveTransactions{$Socket});
950: } else {
951: my $count = $Socket->GetClientData();
952: Log("SUCCESS", "Connection ".$count." to "
953: .$RemoteHost." now ready for action");
954: }
955: ServerToIdle($Socket); # Next work unit or idle.
956:
957: #
958: $LondConnecting = 0; # Best spot I can think of for this.
959: #
960:
961: } elsif ($State eq "SendingRequest") {
962: # We need to be writable for this and probably don't belong
963: # here inthe first place.
964:
965: Debug(6, "SendingRequest state encountered in readable");
966: $Watcher->poll("w");
967: $Watcher->cb(\&LondWritable);
968:
969: } elsif ($State eq "ReceivingReply") {
970:
971:
972: } else {
973: # Invalid state.
974: Debug(4, "Invalid state in LondReadable");
975: }
976: }
977:
978: =pod
979:
980: =head2 LondWritable
981:
982: This function is called whenever a lond connection
983: becomes writable while there is a writeable monitoring
984: event. The action taken is very state dependent:
985:
986: =head3 State = Connected
987:
988: The connection is in the process of sending the 'init' hailing to the
989: lond on the remote end. The Writable member of the connection object
990: is called. On error, call ConnectionError to destroy the connection
991: and remove it from the ActiveConnections hash.
992:
993: =head3 Initialized
994:
995: 'init' has been sent, writability monitoring is removed and
996: readability monitoring is started with LondReadable as the callback.
997:
998: =head3 ChallengeReceived
999:
1000: The connection has received the who are you challenge from the remote
1001: system, and is in the process of sending the challenge
1002: response. Writable is called.
1003:
1004: =head3 ChallengeReplied
1005:
1006: The connection has replied to the initial challenge The we switch to
1007: monitoring readability looking for the server to reply with 'ok'.
1008:
1009: =head3 RequestingKey
1010:
1011: The connection is in the process of requesting its encryption key.
1012: Writable is called.
1013:
1014: =head3 ReceivingKey
1015:
1016: The connection has sent the request for a key. Switch to readability
1017: monitoring to accept the key
1018:
1019: =head3 SendingRequest
1020:
1021: The connection is in the process of sending a request to the server.
1022: This request is part of a client transaction. All the states until
1023: now represent the client setup protocol. Writable is called.
1024:
1025: =head3 ReceivingReply
1026:
1027: The connection has sent a request. Now it must receive a reply.
1028: Readability monitoring is requested.
1029:
1030: This function is an event handler and therefore receives as
1031: a parameter the event that has fired. The data for the watcher
1032: of this event is a reference to a list of one or two elements,
1033: depending on state. The first (and possibly only) element is the
1034: socket. The second (present only if a request is in progress)
1035: is the socket on which to return a reply to the caller.
1036:
1037: =cut
1038:
1039: sub LondWritable {
1040: my $Event = shift;
1041: my $Watcher = $Event->w;
1042: my $Socket = $Watcher->data;
1043: my $State = $Socket->GetState();
1044:
1045: Debug(6,"LondWritable State = ".$State."\n");
1046:
1047:
1048: # Figure out what to do depending on the state of the socket:
1049:
1050:
1051:
1052:
1053: SocketDump(6,$Socket);
1054:
1055: # If the socket is writable, we must always write.
1056: # Only by writing will we undergo state transitions.
1057: # Old logic wrote in state specific code below, however
1058: # That forces us at least through another invocation of
1059: # this function after writability is possible again.
1060: # This logic also factors out common code for handling
1061: # write failures... in all cases, write failures
1062: # Kill the socket.
1063: # This logic makes the branches of the >big< if below
1064: # so that the writing states are actually NO-OPs.
1065:
1066: if ($Socket->Writable() != 0) {
1067: # The write resulted in an error.
1068: # We'll treat this as if the socket got disconnected:
1069: Log("WARNING", "Connection to ".$RemoteHost.
1070: " has been disconnected");
1071: if(exists($ActiveTransactions{$Socket})) {
1072: FailTransaction($ActiveTransactions{$Socket});
1073: } else {
1074: # In the process of conneting, so need to turn that off.
1075:
1076: $LondConnecting = 0;
1077: }
1078: $Watcher->cancel();
1079: KillSocket($Socket);
1080: return;
1081: }
1082:
1083:
1084:
1085: if ($State eq "Connected") {
1086:
1087: # "init" is being sent...
1088:
1089: } elsif ($State eq "Initialized") {
1090:
1091: # Now that init was sent, we switch
1092: # to watching for readability:
1093:
1094: $Watcher->cb(\&LondReadable);
1095: $Watcher->poll("r");
1096:
1097: } elsif ($State eq "ChallengeReceived") {
1098: # We received the challenge, now we
1099: # are echoing it back. This is a no-op,
1100: # we're waiting for the state to change
1101:
1102: } elsif ($State eq "ChallengeReplied") {
1103: # The echo was sent back, so we switch
1104: # to watching readability.
1105:
1106: $Watcher->cb(\&LondReadable);
1107: $Watcher->poll("r");
1108: } elsif ($State eq "RequestingVersion") {
1109: # Sending the peer a version request...
1110:
1111: } elsif ($State eq "ReadingVersionString") {
1112: # Transition to read since we have sent the
1113: # version command and now just need to read the
1114: # version string from the peer:
1115:
1116: $Watcher->cb(\&LondReadable);
1117: $Watcher->poll("r");
1118:
1119: } elsif ($State eq "SetHost") {
1120: # Setting the remote domain...
1121:
1122: } elsif ($State eq "HostSet") {
1123: # Back to readable to get the ok.
1124:
1125: $Watcher->cb(\&LondReadable);
1126: $Watcher->poll("r");
1127:
1128:
1129: } elsif ($State eq "RequestingKey") {
1130: # At this time we're requesting the key.
1131: # again, this is essentially a no-op.
1132:
1133: } elsif ($State eq "ReceivingKey") {
1134: # Now we need to wait for the key
1135: # to come back from the peer:
1136:
1137: $Watcher->cb(\&LondReadable);
1138: $Watcher->poll("r");
1139:
1140: } elsif ($State eq "SendingRequest") {
1141:
1142: # At this time we are sending a request to the
1143: # peer... write the next chunk:
1144:
1145:
1146: } elsif ($State eq "ReceivingReply") {
1147: # The send has completed. Wait for the
1148: # data to come in for a reply.
1149: Debug(8,"Writable sent request/receiving reply");
1150: $Watcher->cb(\&LondReadable);
1151: $Watcher->poll("r");
1152:
1153: } else {
1154: # Control only passes here on an error:
1155: # the socket state does not match any
1156: # of the known states... so an error
1157: # must be logged.
1158:
1159: &Debug(4, "Invalid socket state ".$State."\n");
1160: }
1161:
1162: }
1163:
1164: =pod
1165:
1166: =cut
1167:
1168:
1169: sub QueueDelayed {
1170: Debug(3,"QueueDelayed called");
1171:
1172: my $path = "$perlvar{'lonSockDir'}/delayed";
1173:
1174: Debug(4, "Delayed path: ".$path);
1175: opendir(DIRHANDLE, $path);
1176:
1177: my $host_id_re = '(?:'.join('|',map {quotemeta($_)} (@all_host_ids)).')';
1178: my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
1179: closedir(DIRHANDLE);
1180: foreach my $dfname (sort(@alldelayed)) {
1181: my $reqfile = "$path/$dfname";
1182: my ($host_id) = ($dfname =~ /\.([^.]*)$/);
1183: Debug(4, "queueing ".$reqfile." for $host_id");
1184: my $Handle = IO::File->new($reqfile);
1185: my $cmd = <$Handle>;
1186: chomp $cmd; # There may or may not be a newline...
1187: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1188: my $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
1189: $Transaction->SetDeferred($reqfile);
1190: QueueTransaction($Transaction);
1191: }
1192:
1193: }
1194:
1195: =pod
1196:
1197: =head2 MakeLondConnection
1198:
1199: Create a new lond connection object, and start it towards its initial
1200: idleness. Once idle, it becomes eligible to receive transactions
1201: from the work queue. If the work queue is not empty when the
1202: connection is completed and becomes idle, it will dequeue an entry and
1203: start off on it.
1204:
1205: =cut
1206:
1207: sub MakeLondConnection {
1208: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1209: .GetServerPort());
1210:
1211: my $Connection = LondConnection->new(&GetServerHost(),
1212: &GetServerPort(),
1213: &GetHostId());
1214:
1215: if($Connection eq undef) {
1216: Log("CRITICAL","Failed to make a connection with lond.");
1217: $ConnectionRetriesLeft--;
1218: return 0; # Failure.
1219: } else {
1220:
1221: $LondConnecting = 1; # Connection in progress.
1222: # The connection needs to have writability
1223: # monitored in order to send the init sequence
1224: # that starts the whole authentication/key
1225: # exchange underway.
1226: #
1227: my $Socket = $Connection->GetSocket();
1228: if($Socket eq undef) {
1229: &child_exit(-1, "did not get a socket from the connection");
1230: } else {
1231: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1232: }
1233:
1234: $Connection->SetTimeoutCallback(\&SocketTimeout);
1235:
1236: my $event = Event->io(fd => $Socket,
1237: poll => 'w',
1238: cb => \&LondWritable,
1239: data => $Connection,
1240: desc => 'Connection to lond server');
1241: $ActiveConnections{$Connection} = $event;
1242: if ($ConnectionCount == 0) {
1243: &SetupTimer; # Need to handle timeouts with connections...
1244: }
1245: $ConnectionCount++;
1246: $Connection->SetClientData($ConnectionCount);
1247: Debug(4, "Connection count = ".$ConnectionCount);
1248: if($ConnectionCount == 1) { # First Connection:
1249: QueueDelayed;
1250: }
1251: Log("SUCCESS", "Created connection ".$ConnectionCount
1252: ." to host ".GetServerHost());
1253: return 1; # Return success.
1254: }
1255:
1256: }
1257:
1258: =pod
1259:
1260: =head2 StartRequest
1261:
1262: Starts a lond request going on a specified lond connection.
1263: parameters are:
1264:
1265: =item $Lond
1266:
1267: Connection to the lond that will send the transaction and receive the
1268: reply.
1269:
1270: =item $Client
1271:
1272: Connection to the client that is making this request. We got the
1273: request from this socket, and when the request has been relayed to
1274: lond and we get a reply back from lond it will get sent to this
1275: socket.
1276:
1277: =item $Request
1278:
1279: The text of the request to send.
1280:
1281: =cut
1282:
1283: sub StartRequest {
1284:
1285: my ($Lond, $Request) = @_;
1286:
1287: Debug(6, "StartRequest: ".$Request->getRequest());
1288:
1289: my $Socket = $Lond->GetSocket();
1290:
1291: $Request->Activate($Lond);
1292: $ActiveTransactions{$Lond} = $Request;
1293:
1294: $Lond->InitiateTransaction($Request->getRequest());
1295: my $event = Event->io(fd => $Socket,
1296: poll => "w",
1297: cb => \&LondWritable,
1298: data => $Lond,
1299: desc => "lond transaction connection");
1300: $ActiveConnections{$Lond} = $event;
1301: Debug(8," Start Request made watcher data with ".$event->data."\n");
1302: }
1303:
1304: =pod
1305:
1306: =head2 QueueTransaction
1307:
1308: If there is an idle lond connection, it is put to work doing this
1309: transaction. Otherwise, the transaction is placed in the work queue.
1310: If placed in the work queue and the maximum number of connections has
1311: not yet been created, a new connection will be started. Our goal is
1312: to eventually have a sufficient number of connections that the work
1313: queue will typically be empty. parameters are:
1314:
1315: =item Socket
1316:
1317: open on the lonc client.
1318:
1319: =item Request
1320:
1321: data to send to the lond.
1322:
1323: =cut
1324:
1325: sub QueueTransaction {
1326:
1327: my $requestData = shift; # This is a LondTransaction.
1328: my $cmd = $requestData->getRequest();
1329:
1330: Debug(6,"QueueTransaction: ".$cmd);
1331:
1332: my $LondSocket = $IdleConnections->pop();
1333: if(!defined $LondSocket) { # Need to queue request.
1334: Debug(5,"Must queue...");
1335: $WorkQueue->enqueue($requestData);
1336: Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
1337: if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {
1338:
1339: if($ConnectionRetriesLeft > 0) {
1340: Debug(5,"Starting additional lond connection");
1341: if(&MakeLondConnection() == 0) {
1342: EmptyQueue(); # Fail transactions, can't make connection.
1343: CloseAllLondConnections; # Should all be closed but...
1344: }
1345: } else {
1346: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1347: $LondConnecting = 0;
1348: EmptyQueue(); # It's worse than that ... he's dead Jim.
1349: CloseAllLondConnections; # Should all be closed but..
1350: }
1351: }
1352: } else { # Can start the request:
1353: Debug(8,"Can start...");
1354: StartRequest($LondSocket, $requestData);
1355: }
1356: }
1357:
1358: #-------------------------- Lonc UNIX socket handling -------------------
1359: =pod
1360:
1361: =head2 ClientRequest
1362:
1363: Callback that is called when data can be read from the UNIX domain
1364: socket connecting us with an apache server process.
1365:
1366: =cut
1367:
1368: sub ClientRequest {
1369: Debug(6, "ClientRequest");
1370: my $event = shift;
1371: my $watcher = $event->w;
1372: my $socket = $watcher->fd;
1373: my $data = $watcher->data;
1374: my $thisread;
1375:
1376: Debug(9, " Watcher named: ".$watcher->desc);
1377:
1378: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1379: Debug(8, "rcv: data length = ".length($thisread)
1380: ." read =".$thisread);
1381: unless (defined $rv && length($thisread)) {
1382: # Likely eof on socket.
1383: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1384: close($socket);
1385: $watcher->cancel();
1386: delete($ActiveClients{$socket});
1387: return;
1388: }
1389: Debug(8,"Data: ".$data." this read: ".$thisread);
1390: $data = $data.$thisread; # Append new data.
1391: $watcher->data($data);
1392: if($data =~ /\n$/) { # Request entirely read.
1393: if ($data eq "close_connection_exit\n") {
1394: Log("CRITICAL",
1395: "Request Close Connection ... exiting");
1396: CloseAllLondConnections();
1397: exit;
1398: } elsif ($data eq "reset_retries\n") {
1399: Log("INFO", "Resetting Connection Retries.");
1400: $ConnectionRetriesLeft = $ConnectionRetries;
1401: &UpdateStatus();
1402: my $Transaction = LondTransaction->new($data);
1403: $Transaction->SetClient($socket);
1404: StartClientReply($Transaction, "ok\n");
1405: $watcher->cancel();
1406: return;
1407: }
1408: Debug(8, "Complete transaction received: ".$data);
1409: if ($LogTransactions) {
1410: Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
1411: }
1412: my $Transaction = LondTransaction->new($data);
1413: $Transaction->SetClient($socket);
1414: QueueTransaction($Transaction);
1415: $watcher->cancel(); # Done looking for input data.
1416: }
1417:
1418: }
1419:
1420: #
1421: # Accept a connection request for a client (lonc child) and
1422: # start up an event watcher to keep an eye on input from that
1423: # Event. This can be called both from NewClient and from
1424: # ChildProcess.
1425: # Parameters:
1426: # $socket - The listener socket.
1427: # Returns:
1428: # NONE
1429: # Side Effects:
1430: # An event is made to watch the accepted connection.
1431: # Active clients hash is updated to reflect the new connection.
1432: # The client connection count is incremented.
1433: #
1434: sub accept_client {
1435: my ($socket) = @_;
1436:
1437: Debug(8, "Entering accept for lonc UNIX socket\n");
1438: my $connection = $socket->accept(); # Accept the client connection.
1439: Debug(8,"Connection request accepted from "
1440: .GetPeername($connection, AF_UNIX));
1441:
1442:
1443: my $description = sprintf("Connection to lonc client %d",
1444: $ClientConnection);
1445: Debug(9, "Creating event named: ".$description);
1446: Event->io(cb => \&ClientRequest,
1447: poll => 'r',
1448: desc => $description,
1449: data => "",
1450: fd => $connection);
1451: $ActiveClients{$connection} = $ClientConnection;
1452: $ClientConnection++;
1453: }
1454:
1455: =pod
1456:
1457: =head2 NewClient
1458:
1459: Callback that is called when a connection is received on the unix
1460: socket for a new client of lonc. The callback is parameterized by the
1461: event.. which is a-priori assumed to be an io event, and therefore has
1462: an fd member that is the Listener socket. We accept the connection
1463: and register a new event on the readability of that socket:
1464:
1465: =cut
1466:
1467: sub NewClient {
1468: Debug(6, "NewClient");
1469: my $event = shift; # Get the event parameters.
1470: my $watcher = $event->w;
1471: my $socket = $watcher->fd; # Get the event' socket.
1472:
1473: &accept_client($socket);
1474: }
1475:
1476: =pod
1477:
1478: =head2 GetLoncSocketPath
1479:
1480: Returns the name of the UNIX socket on which to listen for client
1481: connections.
1482:
1483: =head2 Parameters:
1484:
1485: host (optional) - Name of the host socket to return.. defaults to
1486: the return from GetServerHost().
1487:
1488: =cut
1489:
1490: sub GetLoncSocketPath {
1491:
1492: my $host = GetServerHost(); # Default host.
1493: if (@_) {
1494: ($host) = @_; # Override if supplied.
1495: }
1496: return $UnixSocketDir."/".$host;
1497: }
1498:
1499: =pod
1500:
1501: =head2 GetServerHost
1502:
1503: Returns the host whose lond we talk with.
1504:
1505: =cut
1506:
1507: sub GetServerHost {
1508: return $RemoteHost; # Setup by the fork.
1509: }
1510:
1511: =pod
1512:
1513: =head2 GetServerId
1514:
1515: Returns the hostid whose lond we talk with.
1516:
1517: =cut
1518:
1519: sub GetHostId {
1520: return $RemoteHostId; # Setup by the fork.
1521: }
1522:
1523: =pod
1524:
1525: =head2 GetServerPort
1526:
1527: Returns the lond port number.
1528:
1529: =cut
1530:
1531: sub GetServerPort {
1532: return $perlvar{londPort};
1533: }
1534:
1535: =pod
1536:
1537: =head2 SetupLoncListener
1538:
1539: Setup a lonc listener event. The event is called when the socket
1540: becomes readable.. that corresponds to the receipt of a new
1541: connection. The event handler established will accept the connection
1542: (creating a communications channel), that in turn will establish
1543: another event handler to subess requests.
1544:
1545: =head2 Parameters:
1546:
1547: host (optional) Name of the host to set up a unix socket to.
1548:
1549: =cut
1550:
1551: sub SetupLoncListener {
1552: my ($host,$SocketName) = @_;
1553: if (!$host) { $host = &GetServerHost(); }
1554: if (!$SocketName) { $SocketName = &GetLoncSocketPath($host); }
1555:
1556:
1557: unlink($SocketName);
1558:
1559: my $socket;
1560: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1561: Listen => 250,
1562: Type => SOCK_STREAM)) {
1563: if($I_am_child) {
1564: &child_exit(-1, "Failed to create a lonc listener socket");
1565: } else {
1566: die "Failed to create a lonc listner socket";
1567: }
1568: }
1569: return $socket;
1570: }
1571:
1572: #
1573: # Toggle transaction logging.
1574: # Implicit inputs:
1575: # LogTransactions
1576: # Implicit Outputs:
1577: # LogTransactions
1578: sub ToggleTransactionLogging {
1579: print STDERR "Toggle transaction logging...\n";
1580: if(!$LogTransactions) {
1581: $LogTransactions = 1;
1582: } else {
1583: $LogTransactions = 0;
1584: }
1585:
1586:
1587: Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
1588: }
1589:
1590: =pod
1591:
1592: =head2 ChildStatus
1593:
1594: Child USR1 signal handler to report the most recent status
1595: into the status file.
1596:
1597: We also use this to reset the retries count in order to allow the
1598: client to retry connections with a previously dead server.
1599:
1600: =cut
1601:
1602: sub ChildStatus {
1603: my $event = shift;
1604: my $watcher = $event->w;
1605:
1606: Debug(2, "Reporting child status because : ".$watcher->data);
1607: my $docdir = $perlvar{'lonDocRoot'};
1608:
1609: open(LOG,">>$docdir/lon-status/loncstatus.txt");
1610: flock(LOG,LOCK_EX);
1611: print LOG $$."\t".$RemoteHost."\t".$Status."\t".
1612: $RecentLogEntry."\n";
1613: #
1614: # Write out information about each of the connections:
1615: #
1616: if ($DebugLevel > 2) {
1617: print LOG "Active connection statuses: \n";
1618: my $i = 1;
1619: print STDERR "================================= Socket Status Dump:\n";
1620: foreach my $item (keys %ActiveConnections) {
1621: my $Socket = $ActiveConnections{$item}->data;
1622: my $state = $Socket->GetState();
1623: print LOG "Connection $i State: $state\n";
1624: print STDERR "---------------------- Connection $i \n";
1625: $Socket->Dump(-1); # Ensure it gets dumped..
1626: $i++;
1627: }
1628: }
1629: flock(LOG,LOCK_UN);
1630: close(LOG);
1631: $ConnectionRetriesLeft = $ConnectionRetries;
1632: UpdateStatus();
1633: }
1634:
1635: =pod
1636:
1637: =head2 SignalledToDeath
1638:
1639: Called in response to a signal that causes a chid process to die.
1640:
1641: =cut
1642:
1643:
1644: sub SignalledToDeath {
1645: my $event = shift;
1646: my $watcher= $event->w;
1647:
1648: Debug(2,"Signalled to death! via ".$watcher->data);
1649: my ($signal) = $watcher->data;
1650: chomp($signal);
1651: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1652: ."died through "."\"$signal\"");
1653: #LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1654: # ."\"$signal\"");
1655: exit 0;
1656:
1657: }
1658:
1659: =pod
1660:
1661: =head2 ToggleDebug
1662:
1663: This sub toggles trace debugging on and off.
1664:
1665: =cut
1666:
1667: sub ToggleDebug {
1668: my $Current = $DebugLevel;
1669: $DebugLevel = $NextDebugLevel;
1670: $NextDebugLevel = $Current;
1671:
1672: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1673:
1674: }
1675:
1676: =pod
1677:
1678: =head2 ChildProcess
1679:
1680: This sub implements a child process for a single lonc daemon.
1681: Optional parameter:
1682: $socket - if provided, this is a socket already open for listening
1683: on the client socket. Otherwise, a new listener is set up.
1684:
1685: =cut
1686:
1687: sub ChildProcess {
1688: # We've inherited all the
1689: # events of our parent and those have to be cancelled or else
1690: # all holy bloody chaos will result.. trust me, I already made
1691: # >that< mistake.
1692:
1693: my $host = GetServerHost();
1694: foreach my $listener (keys %parent_dispatchers) {
1695: my $watcher = $parent_dispatchers{$listener};
1696: my $s = $watcher->fd;
1697: if ($listener ne $host) { # Close everyone but me.
1698: Debug(5, "Closing listen socket for $listener");
1699: $s->close();
1700: }
1701: Debug(5, "Killing watcher for $listener");
1702:
1703: $watcher->cancel();
1704: delete($parent_dispatchers{$listener});
1705:
1706: }
1707:
1708: # kill off the parent's signal handlers too!
1709: #
1710:
1711: for my $handler (keys %parent_handlers) {
1712: my $watcher = $parent_handlers{$handler};
1713: $watcher->cancel();
1714: delete($parent_handlers{$handler});
1715: }
1716:
1717: $I_am_child = 1; # Seems like in spite of it all I may still getting
1718: # parent event dispatches.. flag I'm a child.
1719:
1720:
1721: #
1722: # Signals must be handled by the Event framework...
1723: #
1724:
1725: Event->signal(signal => "QUIT",
1726: cb => \&SignalledToDeath,
1727: data => "QUIT");
1728: Event->signal(signal => "HUP",
1729: cb => \&ChildStatus,
1730: data => "HUP");
1731: Event->signal(signal => "USR1",
1732: cb => \&ChildStatus,
1733: data => "USR1");
1734: Event->signal(signal => "USR2",
1735: cb => \&ToggleTransactionLogging);
1736: Event->signal(signal => "INT",
1737: cb => \&ToggleDebug,
1738: data => "INT");
1739:
1740: # Block the pipe signal we'll get when the socket disconnects. We detect
1741: # socket disconnection via send/receive failures. On disconnect, the
1742: # socket becomes readable .. which will force the disconnect detection.
1743:
1744: my $set = POSIX::SigSet->new(SIGPIPE);
1745: sigprocmask(SIG_BLOCK, $set);
1746:
1747: # Figure out if we got passed a socket or need to open one to listen for
1748: # client requests.
1749:
1750: my ($socket) = @_;
1751: if (!$socket) {
1752:
1753: $socket = SetupLoncListener();
1754: }
1755: # Establish an event to listen for client connection requests.
1756:
1757:
1758: Event->io(cb => \&NewClient,
1759: poll => 'r',
1760: desc => 'Lonc Listener Unix Socket',
1761: fd => $socket);
1762:
1763: $Event::DebugLevel = $DebugLevel;
1764:
1765: Debug(9, "Making initial lond connection for ".$RemoteHost);
1766:
1767: # Setup the initial server connection:
1768:
1769: # &MakeLondConnection(); // let first work request do it.
1770:
1771: # need to accept the connection since the event may not fire.
1772:
1773: &accept_client($socket);
1774:
1775: Debug(9,"Entering event loop");
1776: my $ret = Event::loop(); # Start the main event loop.
1777:
1778:
1779: &child_exit (-1,"Main event loop exited!!!");
1780: }
1781:
1782: # Create a new child for host passed in:
1783:
1784: sub CreateChild {
1785: my ($host, $hostid) = @_;
1786:
1787: my $sigset = POSIX::SigSet->new(SIGINT);
1788: sigprocmask(SIG_BLOCK, $sigset);
1789: $RemoteHost = $host;
1790: ShowStatus('Parent keeping the flock'); # Update time in status message.
1791: Log("CRITICAL", "Forking server for ".$host);
1792: my $pid = fork;
1793: if($pid) { # Parent
1794: $RemoteHost = "Parent";
1795: $ChildPid{$pid} = $host;
1796: sigprocmask(SIG_UNBLOCK, $sigset);
1797: undef(@all_host_ids);
1798: } else { # child.
1799: $RemoteHostId = $hostid;
1800: ShowStatus("Connected to ".$RemoteHost);
1801: $SIG{INT} = 'DEFAULT';
1802: sigprocmask(SIG_UNBLOCK, $sigset);
1803: &ChildProcess(); # Does not return.
1804: }
1805: }
1806:
1807: # parent_client_connection:
1808: # Event handler that processes client connections for the parent process.
1809: # This sub is called when the parent is listening on a socket and
1810: # a connection request arrives. We must:
1811: # Start a child process to accept the connection request.
1812: # Kill our listen on the socket.
1813: # Parameter:
1814: # event - The event object that was created to monitor this socket.
1815: # event->w->fd is the socket.
1816: # Returns:
1817: # NONE
1818: #
1819: sub parent_client_connection {
1820: if ($I_am_child) {
1821: # Should not get here, but seem to anyway:
1822: &Debug(5," Child caught parent client connection event!!");
1823: my ($event) = @_;
1824: my $watcher = $event->w;
1825: $watcher->cancel(); # Try to kill it off again!!
1826: } else {
1827: &Debug(9, "parent_client_connection");
1828: my ($event) = @_;
1829: my $watcher = $event->w;
1830: my $socket = $watcher->fd;
1831: my $connection = $socket->accept(); # Accept the client connection.
1832: Event->io(cb => \&get_remote_hostname,
1833: poll => 'r',
1834: data => "",
1835: fd => $connection);
1836: }
1837: }
1838:
1839: sub get_remote_hostname {
1840: my ($event) = @_;
1841: my $watcher = $event->w;
1842: my $socket = $watcher->fd;
1843:
1844: my $thisread;
1845: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1846: Debug(8, "rcv: data length = ".length($thisread)." read =".$thisread);
1847: if (!defined($rv) || length($thisread) == 0) {
1848: # Likely eof on socket.
1849: Debug(5,"Client Socket closed on lonc for p_c_c");
1850: close($socket);
1851: $watcher->cancel();
1852: return;
1853: }
1854:
1855: my $data = $watcher->data().$thisread;
1856: $watcher->data($data);
1857: if($data =~ /\n$/) { # Request entirely read.
1858: chomp($data);
1859: } else {
1860: return;
1861: }
1862:
1863: &Debug(5,"Creating child for $data (parent_client_connection)");
1864: (my $hostname,my $lonid,@all_host_ids) = split(':',$data);
1865: $ChildHost{$hostname}++;
1866: if ($ChildHost{$hostname} == 1) {
1867: &CreateChild($hostname,$lonid);
1868: } else {
1869: &Log('WARNING',"Request for a second child on $hostname");
1870: }
1871: # Clean up the listen since now the child takes over until it exits.
1872: $watcher->cancel(); # Nolonger listening to this event
1873: $socket->send("done\n");
1874: $socket->close();
1875: }
1876:
1877: # parent_listen:
1878: # Opens a socket and starts a listen for the parent process on a client UNIX
1879: # domain socket.
1880: #
1881: # This involves:
1882: # Creating a socket for listen.
1883: # Removing any socket lock file
1884: # Adding an event handler for this socket becoming readable
1885: # To the parent's event dispatcher.
1886: # Parameters:
1887: # loncapa_host - LonCAPA cluster name of the host represented by the client
1888: # socket.
1889: # Returns:
1890: # NONE
1891: #
1892: sub parent_listen {
1893: my ($loncapa_host) = @_;
1894: Debug(5, "parent_listen: $loncapa_host");
1895:
1896: my ($socket,$file);
1897: if (!$loncapa_host) {
1898: $loncapa_host = 'common_parent';
1899: $file = $perlvar{'lonSockCreate'};
1900: } else {
1901: $file = &GetLoncSocketPath($loncapa_host);
1902: }
1903: $socket = &SetupLoncListener($loncapa_host,$file);
1904:
1905: $listening_to{$socket} = $loncapa_host;
1906: if (!$socket) {
1907: die "Unable to create a listen socket for $loncapa_host";
1908: }
1909:
1910: my $lock_file = $file.".lock";
1911: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1912:
1913: my $watcher =
1914: Event->io(cb => \&parent_client_connection,
1915: poll => 'r',
1916: desc => "Parent listener unix socket ($loncapa_host)",
1917: data => "",
1918: fd => $socket);
1919: $parent_dispatchers{$loncapa_host} = $watcher;
1920:
1921: }
1922:
1923: sub parent_clean_up {
1924: my ($loncapa_host) = @_;
1925: Debug(1, "parent_clean_up: $loncapa_host");
1926:
1927: my $socket_file = &GetLoncSocketPath($loncapa_host);
1928: unlink($socket_file); # No problem if it doesn't exist yet [startup e.g.]
1929: my $lock_file = $socket_file.".lock";
1930: unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
1931: }
1932:
1933:
1934:
1935: # This sub initiates a listen on the common unix domain lonc client socket.
1936: # loncnew starts up with no children, and only spawns off children when a
1937: # connection request occurs on the common client unix socket. The spawned
1938: # child continues to run until it has been idle a while at which point it
1939: # eventually exits and once more the parent picks up the listen.
1940: #
1941: # Parameters:
1942: # NONE
1943: # Implicit Inputs:
1944: # The configuration file that has been read in by LondConnection.
1945: # Returns:
1946: # NONE
1947: #
1948: sub listen_on_common_socket {
1949: Debug(5, "listen_on_common_socket");
1950: &parent_listen();
1951: }
1952:
1953: # server_died is called whenever a child process exits.
1954: # Since this is dispatched via a signal, we must process all
1955: # dead children until there are no more left. The action
1956: # is to:
1957: # - Remove the child from the bookeeping hashes
1958: # - Re-establish a listen on the unix domain socket associated
1959: # with that host.
1960: # Parameters:
1961: # The event, but we don't actually care about it.
1962: sub server_died {
1963: &Debug(9, "server_died called...");
1964:
1965: while(1) { # Loop until waitpid nowait fails.
1966: my $pid = waitpid(-1, WNOHANG);
1967: if($pid <= 0) {
1968: return; # Nothing left to wait for.
1969: }
1970: # need the host to restart:
1971:
1972: my $host = $ChildPid{$pid};
1973: if($host) { # It's for real...
1974: &Debug(9, "Caught sigchild for $host");
1975: delete($ChildPid{$pid});
1976: delete($ChildHost{$host});
1977: &parent_clean_up($host);
1978:
1979: } else {
1980: &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
1981: }
1982: }
1983:
1984: }
1985:
1986: #
1987: # Parent process logic pass 1:
1988: # For each entry in the hosts table, we will
1989: # fork off an instance of ChildProcess to service the transactions
1990: # to that host. Each pid will be entered in a global hash
1991: # with the value of the key, the host.
1992: # The parent will then enter a loop to wait for process exits.
1993: # Each exit gets logged and the child gets restarted.
1994: #
1995:
1996: #
1997: # Fork and start in new session so hang-up isn't going to
1998: # happen without intent.
1999: #
2000:
2001:
2002:
2003:
2004:
2005:
2006: ShowStatus("Forming new session");
2007: my $childpid = fork;
2008: if ($childpid != 0) {
2009: sleep 4; # Give child a chacne to break to
2010: exit 0; # a new sesion.
2011: }
2012: #
2013: # Write my pid into the pid file so I can be located
2014: #
2015:
2016: ShowStatus("Parent writing pid file:");
2017: my $execdir = $perlvar{'lonDaemons'};
2018: open (PIDSAVE, ">$execdir/logs/lonc.pid");
2019: print PIDSAVE "$$\n";
2020: close(PIDSAVE);
2021:
2022:
2023:
2024: if (POSIX::setsid() < 0) {
2025: print "Could not create new session\n";
2026: exit -1;
2027: }
2028:
2029: ShowStatus("Forking node servers");
2030:
2031: Log("CRITICAL", "--------------- Starting children ---------------");
2032:
2033: LondConnection::ReadConfig; # Read standard config files.
2034:
2035: $RemoteHost = "[parent]";
2036: &listen_on_common_socket();
2037:
2038: $RemoteHost = "Parent Server";
2039:
2040: # Maintain the population:
2041:
2042: ShowStatus("Parent keeping the flock");
2043:
2044:
2045: # We need to setup a SIGChild event to handle the exit (natural or otherwise)
2046: # of the children.
2047:
2048: Event->signal(cb => \&server_died,
2049: desc => "Child exit handler",
2050: signal => "CHLD");
2051:
2052:
2053: # Set up all the other signals we set up.
2054:
2055: $parent_handlers{INT} = Event->signal(cb => \&Terminate,
2056: desc => "Parent INT handler",
2057: signal => "INT");
2058: $parent_handlers{TERM} = Event->signal(cb => \&Terminate,
2059: desc => "Parent TERM handler",
2060: signal => "TERM");
2061: $parent_handlers{HUP} = Event->signal(cb => \&KillThemAll,
2062: desc => "Parent HUP handler.",
2063: signal => "HUP");
2064: $parent_handlers{USR1} = Event->signal(cb => \&CheckKids,
2065: desc => "Parent USR1 handler",
2066: signal => "USR1");
2067: $parent_handlers{USR2} = Event->signal(cb => \&UpdateKids,
2068: desc => "Parent USR2 handler.",
2069: signal => "USR2");
2070:
2071: # Start procdesing events.
2072:
2073: $Event::DebugLevel = $DebugLevel;
2074: Debug(9, "Parent entering event loop");
2075: my $ret = Event::loop();
2076: die "Main Event loop exited: $ret";
2077:
2078: =pod
2079:
2080: =head1 CheckKids
2081:
2082: Since kids do not die as easily in this implementation
2083: as the previous one, there is no need to restart the
2084: dead ones (all dead kids get restarted when they die!!)
2085: The only thing this function does is to pass USR1 to the
2086: kids so that they report their status.
2087:
2088: =cut
2089:
2090: sub CheckKids {
2091: Debug(2, "Checking status of children");
2092: my $docdir = $perlvar{'lonDocRoot'};
2093: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
2094: my $now=time;
2095: my $local=localtime($now);
2096: print $fh "LONC status $local - parent $$ \n\n";
2097: foreach my $host (keys %parent_dispatchers) {
2098: print $fh "LONC Parent process listening for $host\n";
2099: }
2100: foreach my $pid (keys %ChildPid) {
2101: Debug(2, "Sending USR1 -> $pid");
2102: kill 'USR1' => $pid; # Tell Child to report status.
2103: }
2104:
2105: }
2106:
2107: =pod
2108:
2109: =head1 UpdateKids
2110:
2111: parent's SIGUSR2 handler. This handler:
2112:
2113: =item
2114:
2115: Rereads the hosts file.
2116:
2117: =item
2118:
2119: Kills off (via sigint) children for hosts that have disappeared.
2120:
2121: =item
2122:
2123: QUITs children for hosts that already exist (this just forces a status display
2124: and resets the connection retry count for that host.
2125:
2126: =item
2127:
2128: Starts new children for hosts that have been added to the hosts.tab file since
2129: the start of the master program and maintains them.
2130:
2131: =cut
2132:
2133: sub UpdateKids {
2134:
2135: Log("INFO", "Updating connections via SIGUSR2");
2136:
2137: # I'm not sure what I was thinking in the first implementation.
2138: # someone will have to work hard to convince me the effect is any
2139: # different than Restart, especially now that we don't start up
2140: # per host servers automatically, may as well just restart.
2141: # The down side is transactions that are in flight will get timed out
2142: # (lost unless they are critical).
2143:
2144: &KillThemAll();
2145: }
2146:
2147:
2148: =pod
2149:
2150: =head1 Restart
2151:
2152: Signal handler for HUP... all children are killed and
2153: we self restart. This is an el-cheapo way to re-read
2154: the config file.
2155:
2156: =cut
2157:
2158: sub Restart {
2159: &KillThemAll; # First kill all the children.
2160: Log("CRITICAL", "Restarting");
2161: my $execdir = $perlvar{'lonDaemons'};
2162: unlink("$execdir/logs/lonc.pid");
2163: exec("$executable");
2164: }
2165:
2166: =pod
2167:
2168: =head1 KillThemAll
2169:
2170: Signal handler that kills all children by sending them a
2171: SIGHUP. Responds to sigint and sigterm.
2172:
2173: =cut
2174:
2175: sub KillThemAll {
2176: Debug(2, "Kill them all!!");
2177:
2178: #local($SIG{CHLD}) = 'IGNORE';
2179: # Our children >will< die.
2180: # but we need to catch their death and cleanup after them in case this is
2181: # a restart set of kills
2182: my @allpids = keys(%ChildPid);
2183: foreach my $pid (@allpids) {
2184: my $serving = $ChildPid{$pid};
2185: ShowStatus("Nicely Killing lonc for $serving pid = $pid");
2186: Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
2187: kill 'QUIT' => $pid;
2188: }
2189: ShowStatus("Finished killing child processes off.");
2190: }
2191:
2192:
2193: #
2194: # Kill all children via KILL. Just in case the
2195: # first shot didn't get them.
2196:
2197: sub really_kill_them_all_dammit
2198: {
2199: Debug(2, "Kill them all Dammit");
2200: local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
2201: foreach my $pid (keys %ChildPid) {
2202: my $serving = $ChildPid{$pid};
2203: &ShowStatus("Nastily killing lonc for $serving pid = $pid");
2204: Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
2205: kill 'KILL' => $pid;
2206: delete($ChildPid{$pid});
2207: my $execdir = $perlvar{'lonDaemons'};
2208: unlink("$execdir/logs/lonc.pid");
2209: }
2210: }
2211:
2212: =pod
2213:
2214: =head1 Terminate
2215:
2216: Terminate the system.
2217:
2218: =cut
2219:
2220: sub Terminate {
2221: &Log("CRITICAL", "Asked to kill children.. first be nice...");
2222: &KillThemAll;
2223: #
2224: # By now they really should all be dead.. but just in case
2225: # send them all SIGKILL's after a bit of waiting:
2226:
2227: sleep(4);
2228: &Log("CRITICAL", "Now kill children nasty");
2229: &really_kill_them_all_dammit;
2230: Log("CRITICAL","Master process exiting");
2231: exit 0;
2232:
2233: }
2234:
2235: sub my_hostname {
2236: use Sys::Hostname;
2237: my $name = &hostname();
2238: &Debug(9,"Name is $name");
2239: return $name;
2240: }
2241:
2242: =pod
2243:
2244: =head1 Theory
2245:
2246: The event class is used to build this as a single process with an
2247: event driven model. The following events are handled:
2248:
2249: =item UNIX Socket connection Received
2250:
2251: =item Request data arrives on UNIX data transfer socket.
2252:
2253: =item lond connection becomes writable.
2254:
2255: =item timer fires at 1 second intervals.
2256:
2257: All sockets are run in non-blocking mode. Timeouts managed by the timer
2258: handler prevents hung connections.
2259:
2260: Key data structures:
2261:
2262: =item RequestQueue
2263:
2264: A queue of requests received from UNIX sockets that are
2265: waiting for a chance to be forwarded on a lond connection socket.
2266:
2267: =item ActiveConnections
2268:
2269: A hash of lond connections that have transactions in process that are
2270: available to be timed out.
2271:
2272: =item ActiveTransactions
2273:
2274: A hash indexed by lond connections that contain the client reply
2275: socket for each connection that has an active transaction on it.
2276:
2277: =item IdleConnections
2278:
2279: A hash of lond connections that have no work to do. These connections
2280: can be closed if they are idle for a long enough time.
2281:
2282: =cut
2283:
2284: =pod
2285:
2286: =head1 Log messages
2287:
2288: The following is a list of log messages that can appear in the
2289: lonc.log file. Each log file has a severity and a message.
2290:
2291: =over 2
2292:
2293: =item Warning A socket timeout was detected
2294:
2295: If there are pending transactions in the socket's queue,
2296: they are failed (saved if critical). If the connection
2297: retry count gets exceeded by this, the
2298: remote host is marked as dead.
2299: Called when timeouts occurred during the connection and
2300: connection dialog with a remote host.
2301:
2302: =item Critical Host makred DEAD <hostname>
2303:
2304: The numer of retry counts for contacting a host was
2305: exceeded. The host is marked dead an no
2306: further attempts will be made by that child.
2307:
2308: =item Info lonc pipe client hung up on us
2309:
2310: Write to the client pipe indicated no data transferred
2311: Socket to remote host is shut down. Reply to the client
2312: is discarded. Note: This is commented out in &ClientWriteable
2313:
2314: =item Success Reply from lond: <data>
2315:
2316: Can be enabled for debugging by setting LogTransactions to nonzero.
2317: Indicates a successful transaction with lond, <data> is the data received
2318: from the remote lond.
2319:
2320: =item Success A delayed transaction was completed
2321:
2322: A transaction that must be reliable was executed and completed
2323: as lonc restarted. This is followed by a mesage of the form
2324:
2325: S: client-name : request
2326:
2327: =item WARNING Failing transaction <cmd>:<subcmd>
2328:
2329: Transaction failed on a socket, but the failure retry count for the remote
2330: node has not yet been exhausted (the node is not yet marked dead).
2331: cmd is the command, subcmd is the subcommand. This results from a con_lost
2332: when communicating with lond.
2333:
2334: =item WARNING Shutting down a socket
2335:
2336: Called when a socket is being closed to lond. This is emitted both when
2337: idle pruning is being done and when the socket has been disconnected by the remote.
2338:
2339: =item WARNING Lond connection lost.
2340:
2341: Called when a read from lond's socket failed indicating lond has closed the
2342: connection or died. This should be followed by one or more
2343:
2344: "WARNING Failing transaction..." msgs for each in-flight or queued transaction.
2345:
2346: =item INFO Connected to lond version: <version>
2347:
2348: When connection negotiation is complete, the lond version is requested and logged here.
2349:
2350: =item SUCCESS Connection n to host now ready for action
2351:
2352: Emitted when connection has been completed with lond. n is then number of
2353: concurrent connections and host, the host to which the connection has just
2354: been established.
2355:
2356: =item WARNING Connection to host has been disconnected
2357:
2358: Write to a lond resulted in failure status. Connection to lond is dropped.
2359:
2360: =item SUCCESS Created connection n to host host
2361:
2362: Initial connection request to host..(before negotiation).
2363:
2364: =item CRITICAL Request Close Connection ... exiting
2365:
2366: Client has sent "close_connection_exit" The loncnew server is exiting.
2367:
2368: =item INFO Resetting Connection Retries
2369:
2370: Client has sent "reset_retries" The lond connection retries are reset to zero for the
2371: corresponding lond.
2372:
2373: =item SUCCESS Transaction <data>
2374:
2375: Only emitted if the global variable $LogTransactions was set to true.
2376: A client has requested a lond transaction <data> is the contents of the request.
2377:
2378: =item SUCCESS Toggled transaction logging <LogTransactions>
2379:
2380: The state of the $LogTransactions global has been toggled, and its current value
2381: (after being toggled) is displayed. When non zero additional logging of transactions
2382: is enabled for debugging purposes. Transaction logging is toggled on receipt of a USR2
2383: signal.
2384:
2385: =item CRITICAL Abnormal exit. Child <pid> for <host> died thorugh signal.
2386:
2387: QUIT signal received. lonc child process is exiting.
2388:
2389: =item SUCCESS New debugging level for <RemoteHost> now <DebugLevel>
2390:
2391: Debugging toggled for the host loncnew is talking with.
2392: Currently debugging is a level based scheme with higher number
2393: conveying more information. The daemon starts out at
2394: DebugLevel 0 and can toggle back and forth between that and
2395: DebugLevel 2 These are controlled by
2396: the global variables $DebugLevel and $NextDebugLevel
2397: The debug level can go up to 9.
2398: SIGINT toggles the debug level. The higher the debug level the
2399: more debugging information is spewed. See the Debug
2400: sub in loncnew.
2401:
2402: =item CRITICAL Forking server for host
2403:
2404: A child is being created to service requests for the specified host.
2405:
2406:
2407: =item WARNING Request for a second child on hostname
2408:
2409: Somehow loncnew was asked to start a second child on a host that already had a child
2410: servicing it. This request is not honored, but themessage is emitted. This could happen
2411: due to a race condition. When a client attempts to contact loncnew for a new host, a child
2412: is forked off to handle the requests for that server. The parent then backs off the Unix
2413: domain socket leaving it for the child to service all requests. If in the time between
2414: creating the child, and backing off, a new connection request comes in to the unix domain
2415: socket, this could trigger (unlikely but remotely possible),.
2416:
2417: =item CRITICAL ------ Starting Children ----
2418:
2419: This message should probably be changed to "Entering event loop" as the loncnew only starts
2420: children as needed. This message is emitted as new events are established and
2421: the event processing loop is entered.
2422:
2423: =item INFO Updating connections via SIGUSR2
2424:
2425: SIGUSR2 received. The original code would kill all clients, re-read the host file,
2426: then restart children for each host. Now that children are started on demand, this
2427: just kills all child processes and lets requests start them as needed again.
2428:
2429:
2430: =item CRITICAL Restarting
2431:
2432: SigHUP received. all the children are killed and the script exec's itself to start again.
2433:
2434: =item CRITICAL Nicely killing lonc for host pid = <pid>
2435:
2436: Attempting to kill the child that is serving the specified host (pid given) cleanly via
2437: SIGQUIT. The child should handle that, clean up nicely and exit.
2438:
2439: =item CRITICAL Nastily killing lonc for host pid = <pid>
2440:
2441: The child specified did not die when requested via SIGQUIT. Therefore it is killed
2442: via SIGKILL.
2443:
2444: =item CRITICAL Asked to kill children.. first be nice..
2445:
2446: In the parent's INT handler. INT kills the child processes. This inidicate loncnew
2447: is about to attempt to kill all known children via SIGQUIT. This message should be followed
2448: by one "Nicely killing" message for each extant child.
2449:
2450: =item CRITICAL Now kill children nasty
2451:
2452: In the parent's INT handler. remaining children are about to be killed via
2453: SIGKILL. Should be followed by a Nastily killing... for each lonc child that
2454: refused to die.
2455:
2456: =item CRITICAL Master process exiting
2457:
2458: In the parent's INT handler. just prior to the exit 0 call.
2459:
2460: =back
2461:
2462: =cut
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