Annotation of loncom/loncnew, revision 1.26
1.1 foxr 1: #!/usr/bin/perl
1.2 albertel 2: # The LearningOnline Network with CAPA
3: # lonc maintains the connections to remote computers
4: #
1.26 ! foxr 5: # $Id: loncnew,v 1.25 2003/09/23 11:22:14 foxr Exp $
1.2 albertel 6: #
7: # Copyright Michigan State University Board of Trustees
8: #
9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
1.17 foxr 10: ## LON-CAPA is free software; you can redistribute it and/or modify
1.2 albertel 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: #
1.1 foxr 28: #
1.15 foxr 29: # new lonc handles n request out bver m connections to londs.
1.1 foxr 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).
1.7 foxr 36: # - Add general logic for dispatching requests and timeouts. (done).
37: # - Add support for the lonc/lond requests. (done).
1.1 foxr 38: # - Add logging/status monitoring.
39: # - Add Signal handling - HUP restarts. USR1 status report.
1.7 foxr 40: # - Add Configuration file I/O (done).
1.1 foxr 41: # - Add management/status request interface.
1.8 foxr 42: # - Add deferred request capability. (done)
1.9 foxr 43: # - Detect transmission timeouts.
1.7 foxr 44: #
45:
46: # Change log:
1.8 foxr 47: # $Log: loncnew,v $
1.26 ! foxr 48: # Revision 1.25 2003/09/23 11:22:14 foxr
! 49: # Tested ability to receive sigusr2 This is now logged and must be
! 50: # properly implemented as a re-read of hosts and re-init of appropriate
! 51: # children.
! 52: #
1.25 foxr 53: # Revision 1.24 2003/09/16 09:46:42 foxr
54: # Added skeletal infrastructure to support SIGUSR2 update hosts request.
55: #
1.24 foxr 56: # Revision 1.23 2003/09/15 09:24:49 foxr
57: # Add use strict and fix all the fallout from that.
58: #
1.23 foxr 59: # Revision 1.22 2003/09/02 10:34:47 foxr
60: # - Fix errors in host dead detection logic (too many cases where the
61: # retries left were not getting incremented or just not checked).
62: # - Added some additional status to the ps axuww display:
63: # o Remaining retries on a host.
64: # o >>> DEAD <<< indicator if I've given up on a host.
65: # - Tested the SIGHUP will reset the retries remaining count (thanks to
66: # the above status stuff, and get allow the loncnew to re-try again
67: # on the host (thanks to the log).
68: #
1.22 foxr 69: # Revision 1.21 2003/08/26 09:19:51 foxr
70: # How embarrassing... put in the SocketTimeout function in loncnew and forgot
71: # to actually hook it into the LondTransaction. Added this to MakeLondConnection
72: # where it belongs... hopefully transactions (not just connection attempts) will
73: # timeout more speedily than the socket errors will catch it.
74: #
1.21 foxr 75: # Revision 1.20 2003/08/25 18:48:11 albertel
76: # - fixing a forgotten ;
77: #
1.20 albertel 78: # Revision 1.19 2003/08/19 09:31:46 foxr
79: # Get socket directory from configuration rather than the old hard coded test
80: # way that I forgot to un-hard code.
81: #
1.19 foxr 82: # Revision 1.18 2003/08/06 09:52:29 foxr
83: # Also needed to remember to fail in-flight transactions if their sends fail.
84: #
1.18 foxr 85: # Revision 1.17 2003/08/03 00:44:31 foxr
86: # 1. Correct handling of connection failure: Assume it means the host is
87: # unreachable and fail all of the queued transactions. Note that the
88: # inflight transactions should fail on their own time due either to timeout
89: # or send/receive failures.
90: # 2. Correct handling of logs for forced death signals. Pull the signal
91: # from the event watcher.
92: #
1.17 foxr 93: # Revision 1.16 2003/07/29 02:33:05 foxr
94: # Add SIGINT processing to child processes to toggle annoying trace mode
95: # on/off.. will try to use this to isolate the compute boud process issue.
96: #
1.16 foxr 97: # Revision 1.15 2003/07/15 02:07:05 foxr
98: # Added code for lonc/lond transaction timeouts. Who knows if it works right.
99: # The intent is for a timeout to fail any transaction in progress and kill
100: # off the sockt that timed out.
101: #
1.15 foxr 102: # Revision 1.14 2003/07/03 02:10:18 foxr
103: # Get all of the signals to work correctly.
104: #
1.14 foxr 105: # Revision 1.13 2003/07/02 01:31:55 foxr
106: # Added kill -HUP logic (restart).
107: #
1.12 foxr 108: # Revision 1.11 2003/06/25 01:54:44 foxr
109: # Fix more problems with transaction failure.
110: #
1.11 foxr 111: # Revision 1.10 2003/06/24 02:46:04 foxr
112: # Put a limit on the number of times we'll retry a connection.
113: # Start getting the signal stuff put in as well...note that need to get signals
1.22 foxr 114: # going or else the client will permanently give up on dead servers.
1.11 foxr 115: #
1.10 foxr 116: # Revision 1.9 2003/06/13 02:38:43 foxr
117: # Add logging in 'expected format'
118: #
1.9 foxr 119: # Revision 1.8 2003/06/11 02:04:35 foxr
120: # Support delayed transactions... this is done uniformly by encapsulating
121: # transactions in an object ... a LondTransaction that is implemented by
122: # LondTransaction.pm
123: #
1.8 foxr 124: # Revision 1.7 2003/06/03 01:59:39 foxr
125: # complete coding to support deferred transactions.
126: #
1.7 foxr 127: #
1.23 foxr 128: use strict;
1.1 foxr 129: use lib "/home/httpd/lib/perl/";
130: use lib "/home/foxr/newloncapa/types";
131: use Event qw(:DEFAULT );
132: use POSIX qw(:signal_h);
1.12 foxr 133: use POSIX;
1.1 foxr 134: use IO::Socket;
135: use IO::Socket::INET;
136: use IO::Socket::UNIX;
1.9 foxr 137: use IO::File;
1.6 foxr 138: use IO::Handle;
1.1 foxr 139: use Socket;
140: use Crypt::IDEA;
141: use LONCAPA::Queue;
142: use LONCAPA::Stack;
143: use LONCAPA::LondConnection;
1.7 foxr 144: use LONCAPA::LondTransaction;
1.1 foxr 145: use LONCAPA::Configuration;
146: use LONCAPA::HashIterator;
147:
148:
149: #
150: # Disable all signals we might receive from outside for now.
151: #
152:
153:
154: # Read the httpd configuration file to get perl variables
155: # normally set in apache modules:
156:
157: my $perlvarref = LONCAPA::Configuration::read_conf('loncapa.conf');
158: my %perlvar = %{$perlvarref};
159:
160: #
161: # parent and shared variables.
162:
163: my %ChildHash; # by pid -> host.
1.26 ! foxr 164: my %HostToPid; # By host -> pid.
! 165: my %HostHash; # by loncapaname -> IP.
1.1 foxr 166:
167:
1.9 foxr 168: my $MaxConnectionCount = 10; # Will get from config later.
1.1 foxr 169: my $ClientConnection = 0; # Uniquifier for client events.
170:
1.9 foxr 171: my $DebugLevel = 0;
1.16 foxr 172: my $NextDebugLevel= 10; # So Sigint can toggle this.
1.1 foxr 173: my $IdleTimeout= 3600; # Wait an hour before pruning connections.
174:
175: #
176: # The variables below are only used by the child processes.
177: #
178: my $RemoteHost; # Name of host child is talking to.
1.20 albertel 179: my $UnixSocketDir= $perlvar{'lonSockDir'};
1.1 foxr 180: my $IdleConnections = Stack->new(); # Set of idle connections
181: my %ActiveConnections; # Connections to the remote lond.
1.7 foxr 182: my %ActiveTransactions; # LondTransactions in flight.
1.1 foxr 183: my %ActiveClients; # Serial numbers of active clients by socket.
184: my $WorkQueue = Queue->new(); # Queue of pending transactions.
185: my $ConnectionCount = 0;
1.4 foxr 186: my $IdleSeconds = 0; # Number of seconds idle.
1.9 foxr 187: my $Status = ""; # Current status string.
1.14 foxr 188: my $RecentLogEntry = "";
1.10 foxr 189: my $ConnectionRetries=5; # Number of connection retries allowed.
190: my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
1.1 foxr 191:
192: #
1.9 foxr 193: # The hash below gives the HTML format for log messages
194: # given a severity.
195: #
196: my %LogFormats;
197:
198: $LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
199: $LogFormats{"SUCCESS"} = "<font color=green>SUCCESS: %s</font>";
200: $LogFormats{"INFO"} = "<font color=yellow>INFO: %s</font>";
201: $LogFormats{"WARNING"} = "<font color=blue>WARNING: %s</font>";
202: $LogFormats{"DEFAULT"} = " %s ";
203:
1.10 foxr 204:
205:
206: =pod
207:
208: =head2 LogPerm
209:
210: Makes an entry into the permanent log file.
211:
212: =cut
213: sub LogPerm {
214: my $message=shift;
215: my $execdir=$perlvar{'lonDaemons'};
216: my $now=time;
217: my $local=localtime($now);
218: my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
219: print $fh "$now:$message:$local\n";
220: }
1.9 foxr 221:
222: =pod
223:
224: =head2 Log
225:
226: Logs a message to the log file.
227: Parameters:
228:
229: =item severity
230:
231: One of CRITICAL, WARNING, INFO, SUCCESS used to select the
232: format string used to format the message. if the severity is
233: not a defined severity the Default format string is used.
234:
235: =item message
236:
237: The base message. In addtion to the format string, the message
238: will be appended to a string containing the name of our remote
239: host and the time will be formatted into the message.
240:
241: =cut
242:
243: sub Log {
244: my $severity = shift;
245: my $message = shift;
246:
247: if(!$LogFormats{$severity}) {
248: $severity = "DEFAULT";
249: }
250:
251: my $format = $LogFormats{$severity};
252:
253: # Put the window dressing in in front of the message format:
254:
255: my $now = time;
256: my $local = localtime($now);
257: my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
258: my $finalformat = $finalformat.$format."\n";
259:
260: # open the file and put the result.
261:
262: my $execdir = $perlvar{'lonDaemons'};
263: my $fh = IO::File->new(">>$execdir/logs/lonc.log");
264: my $msg = sprintf($finalformat, $message);
1.14 foxr 265: $RecentLogEntry = $msg;
1.9 foxr 266: print $fh $msg;
267:
1.10 foxr 268:
1.9 foxr 269: }
1.6 foxr 270:
1.3 albertel 271:
1.1 foxr 272: =pod
1.3 albertel 273:
274: =head2 GetPeerName
275:
276: Returns the name of the host that a socket object is connected to.
277:
1.1 foxr 278: =cut
279:
280: sub GetPeername {
281: my $connection = shift;
282: my $AdrFamily = shift;
283: my $peer = $connection->peername();
284: my $peerport;
285: my $peerip;
286: if($AdrFamily == AF_INET) {
287: ($peerport, $peerip) = sockaddr_in($peer);
1.23 foxr 288: my $peername = gethostbyaddr($peerip, $AdrFamily);
1.1 foxr 289: return $peername;
290: } elsif ($AdrFamily == AF_UNIX) {
291: my $peerfile;
292: ($peerfile) = sockaddr_un($peer);
293: return $peerfile;
294: }
295: }
296: #----------------------------- Timer management ------------------------
297: =pod
1.3 albertel 298:
1.1 foxr 299: =head2 Debug
1.3 albertel 300:
301: Invoked to issue a debug message.
302:
1.1 foxr 303: =cut
1.3 albertel 304:
1.1 foxr 305: sub Debug {
306: my $level = shift;
307: my $message = shift;
308: if ($level <= $DebugLevel) {
1.23 foxr 309: Log("INFO", "-Debug- $message host = $RemoteHost");
1.1 foxr 310: }
311: }
312:
313: sub SocketDump {
314: my $level = shift;
315: my $socket= shift;
316: if($level <= $DebugLevel) {
317: $socket->Dump();
318: }
319: }
1.3 albertel 320:
1.1 foxr 321: =pod
1.3 albertel 322:
1.5 foxr 323: =head2 ShowStatus
324:
325: Place some text as our pid status.
1.10 foxr 326: and as what we return in a SIGUSR1
1.5 foxr 327:
328: =cut
329: sub ShowStatus {
1.10 foxr 330: my $state = shift;
331: my $now = time;
332: my $local = localtime($now);
333: $Status = $local.": ".$state;
334: $0='lonc: '.$state.' '.$local;
1.5 foxr 335: }
336:
337: =pod
338:
1.15 foxr 339: =head 2 SocketTimeout
340:
341: Called when an action on the socket times out. The socket is
342: destroyed and any active transaction is failed.
343:
344:
345: =cut
346: sub SocketTimeout {
347: my $Socket = shift;
348:
1.22 foxr 349: KillSocket($Socket); # A transaction timeout also counts as
350: # a connection failure:
351: $ConnectionRetriesLeft--;
1.15 foxr 352: }
353:
354: =pod
355:
1.1 foxr 356: =head2 Tick
1.3 albertel 357:
358: Invoked each timer tick.
359:
1.1 foxr 360: =cut
361:
1.5 foxr 362:
1.1 foxr 363: sub Tick {
364: my $client;
1.22 foxr 365: if($ConnectionRetriesLeft > 0) {
366: ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
367: ." Retries remaining: ".$ConnectionRetriesLeft);
368: } else {
369: ShowStatus(GetServerHost()." >> DEAD <<");
370: }
1.4 foxr 371: # Is it time to prune connection count:
372:
373:
374: if($IdleConnections->Count() &&
375: ($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
376: $IdleSeconds++;
377: if($IdleSeconds > $IdleTimeout) { # Prune a connection...
1.23 foxr 378: my $Socket = $IdleConnections->pop();
1.6 foxr 379: KillSocket($Socket);
1.4 foxr 380: }
381: } else {
382: $IdleSeconds = 0; # Reset idle count if not idle.
383: }
1.15 foxr 384: #
385: # For each inflight transaction, tick down its timeout counter.
386: #
1.23 foxr 387: foreach my $item (keys %ActiveTransactions) {
1.15 foxr 388: my $Socket = $ActiveTransactions{$item}->getServer();
389: $Socket->Tick();
390: }
1.5 foxr 391: # Do we have work in the queue, but no connections to service them?
392: # If so, try to make some new connections to get things going again.
393: #
394:
395: my $Requests = $WorkQueue->Count();
1.10 foxr 396: if (($ConnectionCount == 0) && ($Requests > 0)) {
397: if ($ConnectionRetriesLeft > 0) {
398: my $Connections = ($Requests <= $MaxConnectionCount) ?
399: $Requests : $MaxConnectionCount;
400: Debug(1,"Work but no connections, start ".$Connections." of them");
1.22 foxr 401: my $successCount = 0;
1.23 foxr 402: for (my $i =0; $i < $Connections; $i++) {
1.22 foxr 403: $successCount += MakeLondConnection();
404: }
405: if($successCount == 0) { # All connections failed:
406: Debug(1,"Work in queue failed to make any connectiouns\n");
407: EmptyQueue(); # Fail pending transactions with con_lost.
1.10 foxr 408: }
409: } else {
1.22 foxr 410: ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
1.10 foxr 411: Debug(1,"Work in queue, but gave up on connections..flushing\n");
412: EmptyQueue(); # Connections can't be established.
1.5 foxr 413: }
414:
415: }
1.1 foxr 416: }
417:
418: =pod
1.3 albertel 419:
1.1 foxr 420: =head2 SetupTimer
421:
1.3 albertel 422: Sets up a 1 per sec recurring timer event. The event handler is used to:
1.1 foxr 423:
1.3 albertel 424: =item
425:
426: Trigger timeouts on communications along active sockets.
427:
428: =item
429:
430: Trigger disconnections of idle sockets.
1.1 foxr 431:
432: =cut
433:
434: sub SetupTimer {
435: Debug(6, "SetupTimer");
436: Event->timer(interval => 1, debug => 1, cb => \&Tick );
437: }
1.3 albertel 438:
1.1 foxr 439: =pod
1.3 albertel 440:
1.1 foxr 441: =head2 ServerToIdle
1.3 albertel 442:
443: This function is called when a connection to the server is
444: ready for more work.
445:
446: If there is work in the Work queue the top element is dequeued
1.1 foxr 447: and the connection will start to work on it. If the work queue is
448: empty, the connection is pushed on the idle connection stack where
449: it will either get another work unit, or alternatively, if it sits there
450: long enough, it will be shut down and released.
451:
1.3 albertel 452: =cut
1.1 foxr 453:
454: sub ServerToIdle {
455: my $Socket = shift; # Get the socket.
1.7 foxr 456: delete($ActiveTransactions{$Socket}); # Server has no transaction
1.1 foxr 457:
458: &Debug(6, "Server to idle");
459:
460: # If there's work to do, start the transaction:
461:
1.23 foxr 462: my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
1.1 foxr 463: unless($reqdata eq undef) {
1.7 foxr 464: Debug(9, "Queue gave request data: ".$reqdata->getRequest());
465: &StartRequest($Socket, $reqdata);
1.8 foxr 466:
1.1 foxr 467: } else {
468:
469: # There's no work waiting, so push the server to idle list.
470: &Debug(8, "No new work requests, server connection going idle");
471: $IdleConnections->push($Socket);
472: }
473: }
1.3 albertel 474:
1.1 foxr 475: =pod
1.3 albertel 476:
1.1 foxr 477: =head2 ClientWritable
1.3 albertel 478:
479: Event callback for when a client socket is writable.
480:
481: This callback is established when a transaction reponse is
482: avaiable from lond. The response is forwarded to the unix socket
483: as it becomes writable in this sub.
484:
1.1 foxr 485: Parameters:
486:
1.3 albertel 487: =item Event
488:
489: The event that has been triggered. Event->w->data is
490: the data and Event->w->fd is the socket to write.
1.1 foxr 491:
492: =cut
1.3 albertel 493:
1.1 foxr 494: sub ClientWritable {
495: my $Event = shift;
496: my $Watcher = $Event->w;
497: my $Data = $Watcher->data;
498: my $Socket = $Watcher->fd;
499:
500: # Try to send the data:
501:
502: &Debug(6, "ClientWritable writing".$Data);
503: &Debug(9, "Socket is: ".$Socket);
504:
1.6 foxr 505: if($Socket->connected) {
506: my $result = $Socket->send($Data, 0);
507:
508: # $result undefined: the write failed.
509: # otherwise $result is the number of bytes written.
510: # Remove that preceding string from the data.
511: # If the resulting data is empty, destroy the watcher
512: # and set up a read event handler to accept the next
513: # request.
514:
515: &Debug(9,"Send result is ".$result." Defined: ".defined($result));
516: if(defined($result)) {
517: &Debug(9, "send result was defined");
518: if($result == length($Data)) { # Entire string sent.
519: &Debug(9, "ClientWritable data all written");
520: $Watcher->cancel();
521: #
522: # Set up to read next request from socket:
523:
524: my $descr = sprintf("Connection to lonc client %d",
525: $ActiveClients{$Socket});
526: Event->io(cb => \&ClientRequest,
527: poll => 'r',
528: desc => $descr,
529: data => "",
530: fd => $Socket);
531:
532: } else { # Partial string sent.
533: $Watcher->data(substr($Data, $result));
1.15 foxr 534: if($result == 0) { # client hung up on us!!
535: Log("INFO", "lonc pipe client hung up on us!");
536: $Watcher->cancel;
537: $Socket->shutdown(2);
538: $Socket->close();
539: }
1.6 foxr 540: }
541:
542: } else { # Error of some sort...
543:
544: # Some errnos are possible:
545: my $errno = $!;
546: if($errno == POSIX::EWOULDBLOCK ||
547: $errno == POSIX::EAGAIN ||
548: $errno == POSIX::EINTR) {
549: # No action taken?
550: } else { # Unanticipated errno.
551: &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
552: $Watcher->cancel; # Stop the watcher.
553: $Socket->shutdown(2); # Kill connection
554: $Socket->close(); # Close the socket.
555: }
1.1 foxr 556:
557: }
1.6 foxr 558: } else {
559: $Watcher->cancel(); # A delayed request...just cancel.
1.1 foxr 560: }
561: }
562:
563: =pod
1.3 albertel 564:
1.1 foxr 565: =head2 CompleteTransaction
1.3 albertel 566:
567: Called when the reply data has been received for a lond
1.1 foxr 568: transaction. The reply data must now be sent to the
569: ultimate client on the other end of the Unix socket. This is
570: done by setting up a writable event for the socket with the
571: data the reply data.
1.3 albertel 572:
1.1 foxr 573: Parameters:
1.3 albertel 574:
575: =item Socket
576:
577: Socket on which the lond transaction occured. This is a
578: LondConnection. The data received is in the TransactionReply member.
579:
1.7 foxr 580: =item Transaction
1.3 albertel 581:
1.7 foxr 582: The transaction that is being completed.
1.1 foxr 583:
584: =cut
1.3 albertel 585:
1.1 foxr 586: sub CompleteTransaction {
587: &Debug(6,"Complete transaction");
588: my $Socket = shift;
1.7 foxr 589: my $Transaction = shift;
1.1 foxr 590:
1.7 foxr 591: if (!$Transaction->isDeferred()) { # Normal transaction
592: my $data = $Socket->GetReply(); # Data to send.
593: StartClientReply($Transaction, $data);
594: } else { # Delete deferred transaction file.
1.9 foxr 595: Log("SUCCESS", "A delayed transaction was completed");
1.23 foxr 596: LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
1.7 foxr 597: unlink $Transaction->getFile();
598: }
1.6 foxr 599: }
600: =pod
601: =head1 StartClientReply
602:
603: Initiates a reply to a client where the reply data is a parameter.
604:
1.7 foxr 605: =head2 parameters:
606:
607: =item Transaction
608:
609: The transaction for which we are responding to the client.
610:
611: =item data
612:
613: The data to send to apached client.
614:
1.6 foxr 615: =cut
616: sub StartClientReply {
1.7 foxr 617: my $Transaction = shift;
1.6 foxr 618: my $data = shift;
1.1 foxr 619:
1.12 foxr 620:
1.7 foxr 621: my $Client = $Transaction->getClient();
622:
1.1 foxr 623: &Debug(8," Reply was: ".$data);
624: my $Serial = $ActiveClients{$Client};
625: my $desc = sprintf("Connection to lonc client %d",
1.6 foxr 626:
1.1 foxr 627: $Serial);
628: Event->io(fd => $Client,
629: poll => "w",
630: desc => $desc,
631: cb => \&ClientWritable,
632: data => $data);
633: }
1.4 foxr 634: =pod
635: =head2 FailTransaction
636:
637: Finishes a transaction with failure because the associated lond socket
1.7 foxr 638: disconnected. There are two possibilities:
639: - The transaction is deferred: in which case we just quietly
640: delete the transaction since there is no client connection.
641: - The transaction is 'live' in which case we initiate the sending
642: of "con_lost" to the client.
643:
644: Deleting the transaction means killing it from the
645: %ActiveTransactions hash.
1.4 foxr 646:
647: Parameters:
648:
649: =item client
650:
1.7 foxr 651: The LondTransaction we are failing.
652:
1.4 foxr 653: =cut
654:
655: sub FailTransaction {
1.7 foxr 656: my $transaction = shift;
1.17 foxr 657: Log("WARNING", "Failing transaction ".$transaction->getRequest());
1.10 foxr 658: Debug(1, "Failing transaction: ".$transaction->getRequest());
659: if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
1.11 foxr 660: my $client = $transaction->getClient();
1.10 foxr 661: Debug(1," Replying con_lost to ".$transaction->getRequest());
1.11 foxr 662: StartClientReply($transaction, "con_lost\n");
1.7 foxr 663: }
1.22 foxr 664: if($ConnectionRetriesLeft <= 0) {
665: Log("CRITICAL", "Host marked dead: ".GetServerHost());
666: }
1.4 foxr 667:
668: }
669:
670: =pod
1.6 foxr 671: =head1 EmptyQueue
1.7 foxr 672:
1.6 foxr 673: Fails all items in the work queue with con_lost.
1.7 foxr 674: Note that each item in the work queue is a transaction.
675:
1.6 foxr 676: =cut
677: sub EmptyQueue {
1.22 foxr 678: $ConnectionRetriesLeft--; # Counts as connection failure too.
1.6 foxr 679: while($WorkQueue->Count()) {
1.10 foxr 680: my $request = $WorkQueue->dequeue(); # This is a transaction
1.7 foxr 681: FailTransaction($request);
1.6 foxr 682: }
683: }
684:
685: =pod
1.4 foxr 686:
1.9 foxr 687: =head2 CloseAllLondConnections
688:
689: Close all connections open on lond prior to exit e.g.
690:
691: =cut
692: sub CloseAllLondConnections {
1.23 foxr 693: foreach my $Socket (keys %ActiveConnections) {
1.9 foxr 694: KillSocket($Socket);
695: }
696: }
697: =cut
698:
699: =pod
700:
1.4 foxr 701: =head2 KillSocket
702:
703: Destroys a socket. This function can be called either when a socket
704: has died of 'natural' causes or because a socket needs to be pruned due to
705: idleness. If the socket has died naturally, if there are no longer any
706: live connections a new connection is created (in case there are transactions
707: in the queue). If the socket has been pruned, it is never re-created.
708:
709: Parameters:
1.1 foxr 710:
1.4 foxr 711: =item Socket
712:
713: The socket to kill off.
714:
715: =item Restart
716:
717: nonzero if we are allowed to create a new connection.
718:
719:
720: =cut
721: sub KillSocket {
722: my $Socket = shift;
723:
1.17 foxr 724: Log("WARNING", "Shutting down a socket");
1.9 foxr 725: $Socket->Shutdown();
726:
1.7 foxr 727: # If the socket came from the active connection set,
728: # delete its transaction... note that FailTransaction should
729: # already have been called!!!
730: # otherwise it came from the idle set.
731: #
1.4 foxr 732:
733: if(exists($ActiveTransactions{$Socket})) {
734: delete ($ActiveTransactions{$Socket});
735: }
736: if(exists($ActiveConnections{$Socket})) {
737: delete($ActiveConnections{$Socket});
738: }
739: $ConnectionCount--;
1.6 foxr 740:
741: # If the connection count has gone to zero and there is work in the
742: # work queue, the work all gets failed with con_lost.
743: #
744: if($ConnectionCount == 0) {
1.22 foxr 745: EmptyQueue();
1.4 foxr 746: }
747: }
1.1 foxr 748:
749: =pod
1.3 albertel 750:
1.1 foxr 751: =head2 LondReadable
1.3 albertel 752:
1.1 foxr 753: This function is called whenever a lond connection
754: is readable. The action is state dependent:
755:
1.3 albertel 756: =head3 State=Initialized
757:
758: We''re waiting for the challenge, this is a no-op until the
1.1 foxr 759: state changes.
1.3 albertel 760:
1.1 foxr 761: =head3 State=Challenged
1.3 albertel 762:
763: The challenge has arrived we need to transition to Writable.
1.1 foxr 764: The connection must echo the challenge back.
1.3 albertel 765:
1.1 foxr 766: =head3 State=ChallengeReplied
1.3 albertel 767:
768: The challenge has been replied to. The we are receiveing the
1.1 foxr 769: 'ok' from the partner.
1.3 albertel 770:
1.1 foxr 771: =head3 State=RequestingKey
1.3 albertel 772:
773: The ok has been received and we need to send the request for
1.1 foxr 774: an encryption key. Transition to writable for that.
1.3 albertel 775:
1.1 foxr 776: =head3 State=ReceivingKey
1.3 albertel 777:
778: The the key has been requested, now we are reading the new key.
779:
1.1 foxr 780: =head3 State=Idle
1.3 albertel 781:
782: The encryption key has been negotiated or we have finished
1.1 foxr 783: reading data from the a transaction. If the callback data has
784: a client as well as the socket iformation, then we are
785: doing a transaction and the data received is relayed to the client
786: before the socket is put on the idle list.
1.3 albertel 787:
1.1 foxr 788: =head3 State=SendingRequest
1.3 albertel 789:
790: I do not think this state can be received here, but if it is,
1.1 foxr 791: the appropriate thing to do is to transition to writable, and send
792: the request.
1.3 albertel 793:
1.1 foxr 794: =head3 State=ReceivingReply
1.3 albertel 795:
796: We finished sending the request to the server and now transition
1.1 foxr 797: to readable to receive the reply.
798:
799: The parameter to this function are:
1.3 albertel 800:
1.1 foxr 801: The event. Implicit in this is the watcher and its data. The data
802: contains at least the lond connection object and, if a
803: transaction is in progress, the socket attached to the local client.
804:
1.3 albertel 805: =cut
1.1 foxr 806:
807: sub LondReadable {
1.8 foxr 808:
1.1 foxr 809: my $Event = shift;
810: my $Watcher = $Event->w;
811: my $Socket = $Watcher->data;
812: my $client = undef;
813:
1.23 foxr 814: &Debug(6,"LondReadable called state = ".$Socket->GetState());
1.8 foxr 815:
1.1 foxr 816:
817: my $State = $Socket->GetState(); # All action depends on the state.
818:
819: SocketDump(6, $Socket);
1.12 foxr 820: my $status = $Socket->Readable();
1.17 foxr 821:
1.12 foxr 822: &Debug(2, "Socket->Readable returned: $status");
1.1 foxr 823:
1.12 foxr 824: if($status != 0) {
1.4 foxr 825: # bad return from socket read. Currently this means that
826: # The socket has become disconnected. We fail the transaction.
827:
1.17 foxr 828: Log("WARNING",
829: "Lond connection lost.");
1.4 foxr 830: if(exists($ActiveTransactions{$Socket})) {
831: FailTransaction($ActiveTransactions{$Socket});
832: }
833: $Watcher->cancel();
1.6 foxr 834: KillSocket($Socket);
1.22 foxr 835: $ConnectionRetriesLeft--; # Counts as connection failure
1.4 foxr 836: return;
1.1 foxr 837: }
838: SocketDump(6,$Socket);
839:
840: $State = $Socket->GetState(); # Update in case of transition.
841: &Debug(6, "After read, state is ".$State);
842:
843: if($State eq "Initialized") {
844:
845:
846: } elsif ($State eq "ChallengeReceived") {
847: # The challenge must be echoed back; The state machine
848: # in the connection takes care of setting that up. Just
849: # need to transition to writable:
850:
1.8 foxr 851: $Watcher->cb(\&LondWritable);
1.1 foxr 852: $Watcher->poll("w");
853:
854: } elsif ($State eq "ChallengeReplied") {
855:
856:
857: } elsif ($State eq "RequestingKey") {
858: # The ok was received. Now we need to request the key
859: # That requires us to be writable:
860:
1.8 foxr 861: $Watcher->cb(\&LondWritable);
1.1 foxr 862: $Watcher->poll("w");
863:
864: } elsif ($State eq "ReceivingKey") {
865:
866: } elsif ($State eq "Idle") {
867: # If necessary, complete a transaction and then go into the
868: # idle queue.
1.22 foxr 869: # Note that a trasition to idle indicates a live lond
870: # on the other end so reset the connection retries.
871: #
872: $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
1.8 foxr 873: $Watcher->cancel();
1.1 foxr 874: if(exists($ActiveTransactions{$Socket})) {
875: Debug(8,"Completing transaction!!");
876: CompleteTransaction($Socket,
877: $ActiveTransactions{$Socket});
1.9 foxr 878: } else {
879: Log("SUCCESS", "Connection ".$ConnectionCount." to "
880: .$RemoteHost." now ready for action");
1.1 foxr 881: }
882: ServerToIdle($Socket); # Next work unit or idle.
1.6 foxr 883:
1.1 foxr 884: } elsif ($State eq "SendingRequest") {
885: # We need to be writable for this and probably don't belong
886: # here inthe first place.
887:
888: Deubg(6, "SendingRequest state encountered in readable");
889: $Watcher->poll("w");
890: $Watcher->cb(\&LondWritable);
891:
892: } elsif ($State eq "ReceivingReply") {
893:
894:
895: } else {
896: # Invalid state.
897: Debug(4, "Invalid state in LondReadable");
898: }
899: }
1.3 albertel 900:
1.1 foxr 901: =pod
1.3 albertel 902:
1.1 foxr 903: =head2 LondWritable
1.3 albertel 904:
1.1 foxr 905: This function is called whenever a lond connection
906: becomes writable while there is a writeable monitoring
907: event. The action taken is very state dependent:
1.3 albertel 908:
1.1 foxr 909: =head3 State = Connected
1.3 albertel 910:
911: The connection is in the process of sending the 'init' hailing to the
912: lond on the remote end. The connection object''s Writable member is
913: called. On error, ConnectionError is called to destroy the connection
914: and remove it from the ActiveConnections hash
915:
1.1 foxr 916: =head3 Initialized
1.3 albertel 917:
918: 'init' has been sent, writability monitoring is removed and
919: readability monitoring is started with LondReadable as the callback.
920:
1.1 foxr 921: =head3 ChallengeReceived
1.3 albertel 922:
923: The connection has received the who are you challenge from the remote
924: system, and is in the process of sending the challenge
925: response. Writable is called.
926:
1.1 foxr 927: =head3 ChallengeReplied
1.3 albertel 928:
929: The connection has replied to the initial challenge The we switch to
930: monitoring readability looking for the server to reply with 'ok'.
931:
1.1 foxr 932: =head3 RequestingKey
1.3 albertel 933:
934: The connection is in the process of requesting its encryption key.
935: Writable is called.
936:
1.1 foxr 937: =head3 ReceivingKey
1.3 albertel 938:
939: The connection has sent the request for a key. Switch to readability
940: monitoring to accept the key
941:
1.1 foxr 942: =head3 SendingRequest
1.3 albertel 943:
944: The connection is in the process of sending a request to the server.
945: This request is part of a client transaction. All the states until
946: now represent the client setup protocol. Writable is called.
947:
1.1 foxr 948: =head3 ReceivingReply
949:
1.3 albertel 950: The connection has sent a request. Now it must receive a reply.
951: Readability monitoring is requested.
952:
953: This function is an event handler and therefore receives as
1.1 foxr 954: a parameter the event that has fired. The data for the watcher
955: of this event is a reference to a list of one or two elements,
956: depending on state. The first (and possibly only) element is the
957: socket. The second (present only if a request is in progress)
958: is the socket on which to return a reply to the caller.
959:
960: =cut
1.3 albertel 961:
1.1 foxr 962: sub LondWritable {
963: my $Event = shift;
964: my $Watcher = $Event->w;
1.8 foxr 965: my $Socket = $Watcher->data;
966: my $State = $Socket->GetState();
1.1 foxr 967:
1.8 foxr 968: Debug(6,"LondWritable State = ".$State."\n");
1.1 foxr 969:
1.8 foxr 970:
1.1 foxr 971: # Figure out what to do depending on the state of the socket:
972:
973:
974:
975:
976: SocketDump(6,$Socket);
977:
978: if ($State eq "Connected") {
979:
980: if ($Socket->Writable() != 0) {
981: # The write resulted in an error.
1.4 foxr 982: # We'll treat this as if the socket got disconnected:
1.9 foxr 983: Log("WARNING", "Connection to ".$RemoteHost.
984: " has been disconnected");
1.18 foxr 985: FailTransaction($ActiveTransactions{$Socket});
1.4 foxr 986: $Watcher->cancel();
1.6 foxr 987: KillSocket($Socket);
1.4 foxr 988: return;
1.1 foxr 989: }
1.4 foxr 990: # "init" is being sent...
991:
1.1 foxr 992:
993: } elsif ($State eq "Initialized") {
994:
995: # Now that init was sent, we switch
996: # to watching for readability:
997:
1.8 foxr 998: $Watcher->cb(\&LondReadable);
1.1 foxr 999: $Watcher->poll("r");
1000:
1001: } elsif ($State eq "ChallengeReceived") {
1002: # We received the challenge, now we
1003: # are echoing it back. This is a no-op,
1004: # we're waiting for the state to change
1005:
1006: if($Socket->Writable() != 0) {
1.5 foxr 1007:
1008: $Watcher->cancel();
1.6 foxr 1009: KillSocket($Socket);
1.5 foxr 1010: return;
1.1 foxr 1011: }
1012:
1013: } elsif ($State eq "ChallengeReplied") {
1014: # The echo was sent back, so we switch
1015: # to watching readability.
1016:
1.8 foxr 1017: $Watcher->cb(\&LondReadable);
1.1 foxr 1018: $Watcher->poll("r");
1019:
1020: } elsif ($State eq "RequestingKey") {
1021: # At this time we're requesting the key.
1022: # again, this is essentially a no-op.
1023: # we'll write the next chunk until the
1024: # state changes.
1025:
1026: if($Socket->Writable() != 0) {
1027: # Write resulted in an error.
1.5 foxr 1028:
1029: $Watcher->cancel();
1.6 foxr 1030: KillSocket($Socket);
1.5 foxr 1031: return;
1032:
1.1 foxr 1033: }
1034: } elsif ($State eq "ReceivingKey") {
1035: # Now we need to wait for the key
1036: # to come back from the peer:
1037:
1.8 foxr 1038: $Watcher->cb(\&LondReadable);
1.1 foxr 1039: $Watcher->poll("r");
1040:
1041: } elsif ($State eq "SendingRequest") {
1042: # At this time we are sending a request to the
1043: # peer... write the next chunk:
1044:
1045: if($Socket->Writable() != 0) {
1046:
1.5 foxr 1047: if(exists($ActiveTransactions{$Socket})) {
1048: Debug(3, "Lond connection lost, failing transactions");
1049: FailTransaction($ActiveTransactions{$Socket});
1050: }
1051: $Watcher->cancel();
1.6 foxr 1052: KillSocket($Socket);
1.5 foxr 1053: return;
1054:
1.1 foxr 1055: }
1056:
1057: } elsif ($State eq "ReceivingReply") {
1058: # The send has completed. Wait for the
1059: # data to come in for a reply.
1060: Debug(8,"Writable sent request/receiving reply");
1.8 foxr 1061: $Watcher->cb(\&LondReadable);
1.1 foxr 1062: $Watcher->poll("r");
1063:
1064: } else {
1065: # Control only passes here on an error:
1066: # the socket state does not match any
1067: # of the known states... so an error
1068: # must be logged.
1069:
1070: &Debug(4, "Invalid socket state ".$State."\n");
1071: }
1072:
1073: }
1.6 foxr 1074: =pod
1075:
1076: =cut
1077: sub QueueDelayed {
1.8 foxr 1078: Debug(3,"QueueDelayed called");
1079:
1.6 foxr 1080: my $path = "$perlvar{'lonSockDir'}/delayed";
1.8 foxr 1081:
1082: Debug(4, "Delayed path: ".$path);
1.6 foxr 1083: opendir(DIRHANDLE, $path);
1.8 foxr 1084:
1.23 foxr 1085: my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
1.6 foxr 1086: closedir(DIRHANDLE);
1087: my $dfname;
1.8 foxr 1088: my $reqfile;
1089: foreach $dfname (sort @alldelayed) {
1090: $reqfile = "$path/$dfname";
1091: Debug(4, "queueing ".$reqfile);
1.6 foxr 1092: my $Handle = IO::File->new($reqfile);
1093: my $cmd = <$Handle>;
1.8 foxr 1094: chomp $cmd; # There may or may not be a newline...
1.12 foxr 1095: $cmd = $cmd."\n"; # now for sure there's exactly one newline.
1.7 foxr 1096: my $Transaction = LondTransaction->new($cmd);
1097: $Transaction->SetDeferred($reqfile);
1098: QueueTransaction($Transaction);
1.6 foxr 1099: }
1100:
1101: }
1.1 foxr 1102:
1103: =pod
1.3 albertel 1104:
1.1 foxr 1105: =head2 MakeLondConnection
1.3 albertel 1106:
1107: Create a new lond connection object, and start it towards its initial
1108: idleness. Once idle, it becomes elligible to receive transactions
1109: from the work queue. If the work queue is not empty when the
1110: connection is completed and becomes idle, it will dequeue an entry and
1111: start off on it.
1112:
1.1 foxr 1113: =cut
1.3 albertel 1114:
1.1 foxr 1115: sub MakeLondConnection {
1116: Debug(4,"MakeLondConnection to ".GetServerHost()." on port "
1117: .GetServerPort());
1118:
1119: my $Connection = LondConnection->new(&GetServerHost(),
1120: &GetServerPort());
1121:
1122: if($Connection == undef) { # Needs to be more robust later.
1.9 foxr 1123: Log("CRITICAL","Failed to make a connection with lond.");
1.10 foxr 1124: $ConnectionRetriesLeft--;
1125: return 0; # Failure.
1.5 foxr 1126: } else {
1.22 foxr 1127:
1.5 foxr 1128: # The connection needs to have writability
1129: # monitored in order to send the init sequence
1130: # that starts the whole authentication/key
1131: # exchange underway.
1132: #
1133: my $Socket = $Connection->GetSocket();
1134: if($Socket == undef) {
1135: die "did not get a socket from the connection";
1136: } else {
1137: &Debug(9,"MakeLondConnection got socket: ".$Socket);
1138: }
1.1 foxr 1139:
1.21 foxr 1140: $Connection->SetTimeoutCallback(\&SocketTimeout);
1141:
1.23 foxr 1142: my $event = Event->io(fd => $Socket,
1.5 foxr 1143: poll => 'w',
1144: cb => \&LondWritable,
1.8 foxr 1145: data => $Connection,
1.5 foxr 1146: desc => 'Connection to lond server');
1147: $ActiveConnections{$Connection} = $event;
1148:
1149: $ConnectionCount++;
1.8 foxr 1150: Debug(4, "Connection count = ".$ConnectionCount);
1.6 foxr 1151: if($ConnectionCount == 1) { # First Connection:
1152: QueueDelayed;
1153: }
1.9 foxr 1154: Log("SUCESS", "Created connection ".$ConnectionCount
1155: ." to host ".GetServerHost());
1.10 foxr 1156: return 1; # Return success.
1.1 foxr 1157: }
1158:
1159: }
1.3 albertel 1160:
1.1 foxr 1161: =pod
1.3 albertel 1162:
1.1 foxr 1163: =head2 StartRequest
1.3 albertel 1164:
1165: Starts a lond request going on a specified lond connection.
1166: parameters are:
1167:
1168: =item $Lond
1169:
1170: Connection to the lond that will send the transaction and receive the
1171: reply.
1172:
1173: =item $Client
1174:
1175: Connection to the client that is making this request We got the
1176: request from this socket, and when the request has been relayed to
1177: lond and we get a reply back from lond it will get sent to this
1178: socket.
1179:
1180: =item $Request
1181:
1182: The text of the request to send.
1183:
1.1 foxr 1184: =cut
1185:
1186: sub StartRequest {
1187: my $Lond = shift;
1.7 foxr 1188: my $Request = shift; # This is a LondTransaction.
1.1 foxr 1189:
1.7 foxr 1190: Debug(6, "StartRequest: ".$Request->getRequest());
1.1 foxr 1191:
1192: my $Socket = $Lond->GetSocket();
1193:
1.7 foxr 1194: $Request->Activate($Lond);
1195: $ActiveTransactions{$Lond} = $Request;
1.1 foxr 1196:
1.7 foxr 1197: $Lond->InitiateTransaction($Request->getRequest());
1.23 foxr 1198: my $event = Event->io(fd => $Socket,
1.1 foxr 1199: poll => "w",
1200: cb => \&LondWritable,
1201: data => $Lond,
1202: desc => "lond transaction connection");
1203: $ActiveConnections{$Lond} = $event;
1204: Debug(8," Start Request made watcher data with ".$event->data."\n");
1205: }
1206:
1207: =pod
1.3 albertel 1208:
1.1 foxr 1209: =head2 QueueTransaction
1.3 albertel 1210:
1211: If there is an idle lond connection, it is put to work doing this
1212: transaction. Otherwise, the transaction is placed in the work queue.
1213: If placed in the work queue and the maximum number of connections has
1214: not yet been created, a new connection will be started. Our goal is
1215: to eventually have a sufficient number of connections that the work
1216: queue will typically be empty. parameters are:
1217:
1218: =item Socket
1219:
1220: open on the lonc client.
1221:
1222: =item Request
1223:
1224: data to send to the lond.
1.1 foxr 1225:
1226: =cut
1.3 albertel 1227:
1.1 foxr 1228: sub QueueTransaction {
1229:
1.7 foxr 1230: my $requestData = shift; # This is a LondTransaction.
1231: my $cmd = $requestData->getRequest();
1232:
1233: Debug(6,"QueueTransaction: ".$cmd);
1.1 foxr 1234:
1235: my $LondSocket = $IdleConnections->pop();
1236: if(!defined $LondSocket) { # Need to queue request.
1237: Debug(8,"Must queue...");
1238: $WorkQueue->enqueue($requestData);
1239: if($ConnectionCount < $MaxConnectionCount) {
1.22 foxr 1240: if($ConnectionRetriesLeft > 0) {
1241: Debug(4,"Starting additional lond connection");
1242: if(MakeLondConnection() == 0) {
1243: EmptyQueue(); # Fail transactions, can't make connection.
1244: }
1245: } else {
1246: ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
1247: EmptyQueue(); # It's worse than that ... he's dead Jim.
1.17 foxr 1248: }
1.1 foxr 1249: }
1250: } else { # Can start the request:
1251: Debug(8,"Can start...");
1.7 foxr 1252: StartRequest($LondSocket, $requestData);
1.1 foxr 1253: }
1254: }
1255:
1256: #-------------------------- Lonc UNIX socket handling ---------------------
1.3 albertel 1257:
1.1 foxr 1258: =pod
1.3 albertel 1259:
1.1 foxr 1260: =head2 ClientRequest
1.3 albertel 1261: Callback that is called when data can be read from the UNIX domain
1262: socket connecting us with an apache server process.
1.1 foxr 1263:
1264: =cut
1265:
1266: sub ClientRequest {
1267: Debug(6, "ClientRequest");
1268: my $event = shift;
1269: my $watcher = $event->w;
1270: my $socket = $watcher->fd;
1271: my $data = $watcher->data;
1272: my $thisread;
1273:
1274: Debug(9, " Watcher named: ".$watcher->desc);
1275:
1276: my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
1277: Debug(8, "rcv: data length = ".length($thisread)
1278: ." read =".$thisread);
1279: unless (defined $rv && length($thisread)) {
1280: # Likely eof on socket.
1281: Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
1282: close($socket);
1283: $watcher->cancel();
1284: delete($ActiveClients{$socket});
1.10 foxr 1285: return;
1.1 foxr 1286: }
1287: Debug(8,"Data: ".$data." this read: ".$thisread);
1288: $data = $data.$thisread; # Append new data.
1289: $watcher->data($data);
1290: if($data =~ /(.*\n)/) { # Request entirely read.
1.10 foxr 1291: if($data eq "close_connection_exit\n") {
1.9 foxr 1292: Log("CRITICAL",
1293: "Request Close Connection ... exiting");
1294: CloseAllLondConnections();
1295: exit;
1296: }
1.1 foxr 1297: Debug(8, "Complete transaction received: ".$data);
1.8 foxr 1298: my $Transaction = LondTransaction->new($data);
1.7 foxr 1299: $Transaction->SetClient($socket);
1300: QueueTransaction($Transaction);
1.1 foxr 1301: $watcher->cancel(); # Done looking for input data.
1302: }
1303:
1304: }
1305:
1306:
1307: =pod
1.3 albertel 1308:
1.1 foxr 1309: =head2 NewClient
1.3 albertel 1310:
1311: Callback that is called when a connection is received on the unix
1312: socket for a new client of lonc. The callback is parameterized by the
1313: event.. which is a-priori assumed to be an io event, and therefore has
1314: an fd member that is the Listener socket. We Accept the connection
1315: and register a new event on the readability of that socket:
1316:
1.1 foxr 1317: =cut
1.3 albertel 1318:
1.1 foxr 1319: sub NewClient {
1320: Debug(6, "NewClient");
1321: my $event = shift; # Get the event parameters.
1322: my $watcher = $event->w;
1323: my $socket = $watcher->fd; # Get the event' socket.
1324: my $connection = $socket->accept(); # Accept the client connection.
1325: Debug(8,"Connection request accepted from "
1326: .GetPeername($connection, AF_UNIX));
1327:
1328:
1329: my $description = sprintf("Connection to lonc client %d",
1330: $ClientConnection);
1331: Debug(9, "Creating event named: ".$description);
1332: Event->io(cb => \&ClientRequest,
1333: poll => 'r',
1334: desc => $description,
1335: data => "",
1336: fd => $connection);
1337: $ActiveClients{$connection} = $ClientConnection;
1338: $ClientConnection++;
1339: }
1.3 albertel 1340:
1341: =pod
1342:
1343: =head2 GetLoncSocketPath
1344:
1345: Returns the name of the UNIX socket on which to listen for client
1346: connections.
1.1 foxr 1347:
1348: =cut
1.3 albertel 1349:
1.1 foxr 1350: sub GetLoncSocketPath {
1351: return $UnixSocketDir."/".GetServerHost();
1352: }
1353:
1.3 albertel 1354: =pod
1355:
1356: =head2 GetServerHost
1357:
1358: Returns the host whose lond we talk with.
1359:
1.1 foxr 1360: =cut
1.3 albertel 1361:
1.7 foxr 1362: sub GetServerHost {
1.1 foxr 1363: return $RemoteHost; # Setup by the fork.
1364: }
1.3 albertel 1365:
1366: =pod
1367:
1368: =head2 GetServerPort
1369:
1370: Returns the lond port number.
1371:
1.1 foxr 1372: =cut
1.3 albertel 1373:
1.7 foxr 1374: sub GetServerPort {
1.1 foxr 1375: return $perlvar{londPort};
1376: }
1.3 albertel 1377:
1378: =pod
1379:
1380: =head2 SetupLoncListener
1381:
1382: Setup a lonc listener event. The event is called when the socket
1383: becomes readable.. that corresponds to the receipt of a new
1384: connection. The event handler established will accept the connection
1385: (creating a communcations channel), that int turn will establish
1386: another event handler to subess requests.
1.1 foxr 1387:
1388: =cut
1.3 albertel 1389:
1.1 foxr 1390: sub SetupLoncListener {
1391:
1392: my $socket;
1393: my $SocketName = GetLoncSocketPath();
1394: unlink($SocketName);
1.7 foxr 1395: unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
1.1 foxr 1396: Listen => 10,
1397: Type => SOCK_STREAM)) {
1398: die "Failed to create a lonc listner socket";
1399: }
1400: Event->io(cb => \&NewClient,
1401: poll => 'r',
1402: desc => 'Lonc listener Unix Socket',
1403: fd => $socket);
1404: }
1405:
1.14 foxr 1406: =pod
1407:
1408: =head2 ChildStatus
1409:
1410: Child USR1 signal handler to report the most recent status
1411: into the status file.
1412:
1.22 foxr 1413: We also use this to reset the retries count in order to allow the
1414: client to retry connections with a previously dead server.
1.14 foxr 1415: =cut
1416: sub ChildStatus {
1417: my $event = shift;
1418: my $watcher = $event->w;
1419:
1420: Debug(2, "Reporting child status because : ".$watcher->data);
1421: my $docdir = $perlvar{'lonDocRoot'};
1422: my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
1423: print $fh $$."\t".$RemoteHost."\t".$Status."\t".
1424: $RecentLogEntry."\n";
1.22 foxr 1425: $ConnectionRetriesLeft = $ConnectionRetries;
1.14 foxr 1426: }
1427:
1.1 foxr 1428: =pod
1.3 albertel 1429:
1.10 foxr 1430: =head2 SignalledToDeath
1431:
1432: Called in response to a signal that causes a chid process to die.
1433:
1434: =cut
1435:
1436:
1437: sub SignalledToDeath {
1.14 foxr 1438: my $event = shift;
1439: my $watcher= $event->w;
1440:
1441: Debug(2,"Signalled to death! via ".$watcher->data);
1.17 foxr 1442: my ($signal) = $watcher->data;
1.10 foxr 1443: chomp($signal);
1444: Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
1445: ."died through "."\"$signal\"");
1446: LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
1447: ."\"$signal\"");
1.12 foxr 1448: exit 0;
1.10 foxr 1449:
1450: }
1.16 foxr 1451:
1452: =head2 ToggleDebug
1453:
1454: This sub toggles trace debugging on and off.
1455:
1456: =cut
1457:
1458: sub ToggleDebug {
1459: my $Current = $DebugLevel;
1460: $DebugLevel = $NextDebugLevel;
1461: $NextDebugLevel = $Current;
1462:
1463: Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
1464:
1465: }
1466:
1.1 foxr 1467: =head2 ChildProcess
1468:
1469: This sub implements a child process for a single lonc daemon.
1470:
1471: =cut
1472:
1473: sub ChildProcess {
1474:
1475:
1.14 foxr 1476: #
1477: # Signals must be handled by the Event framework...
1478: #
1479:
1480: Event->signal(signal => "QUIT",
1481: cb => \&SignalledToDeath,
1482: data => "QUIT");
1483: Event->signal(signal => "HUP",
1484: cb => \&ChildStatus,
1485: data => "HUP");
1486: Event->signal(signal => "USR1",
1487: cb => \&ChildStatus,
1488: data => "USR1");
1.16 foxr 1489: Event->signal(signal => "INT",
1490: cb => \&ToggleDebug,
1491: data => "INT");
1.1 foxr 1492:
1493: SetupTimer();
1494:
1495: SetupLoncListener();
1496:
1497: $Event::Debuglevel = $DebugLevel;
1498:
1499: Debug(9, "Making initial lond connection for ".$RemoteHost);
1500:
1501: # Setup the initial server connection:
1502:
1.14 foxr 1503: # &MakeLondConnection(); // let first work requirest do it.
1.10 foxr 1504:
1.5 foxr 1505:
1.1 foxr 1506: Debug(9,"Entering event loop");
1507: my $ret = Event::loop(); # Start the main event loop.
1508:
1509:
1510: die "Main event loop exited!!!";
1511: }
1512:
1513: # Create a new child for host passed in:
1514:
1515: sub CreateChild {
1.12 foxr 1516: my $sigset = POSIX::SigSet->new(SIGINT);
1517: sigprocmask(SIG_BLOCK, $sigset);
1.1 foxr 1518: my $host = shift;
1519: $RemoteHost = $host;
1.9 foxr 1520: Log("CRITICAL", "Forking server for ".$host);
1.23 foxr 1521: my $pid = fork;
1.1 foxr 1522: if($pid) { # Parent
1.17 foxr 1523: $RemoteHost = "Parent";
1.1 foxr 1524: $ChildHash{$pid} = $RemoteHost;
1.26 ! foxr 1525: $HostToPid{$host}= $pid;
1.12 foxr 1526: sigprocmask(SIG_UNBLOCK, $sigset);
1527:
1.1 foxr 1528: } else { # child.
1.5 foxr 1529: ShowStatus("Connected to ".$RemoteHost);
1.23 foxr 1530: $SIG{INT} = 'DEFAULT';
1.12 foxr 1531: sigprocmask(SIG_UNBLOCK, $sigset);
1532: ChildProcess; # Does not return.
1.1 foxr 1533: }
1534:
1535: }
1536: #
1537: # Parent process logic pass 1:
1538: # For each entry in the hosts table, we will
1539: # fork off an instance of ChildProcess to service the transactions
1540: # to that host. Each pid will be entered in a global hash
1541: # with the value of the key, the host.
1542: # The parent will then enter a loop to wait for process exits.
1543: # Each exit gets logged and the child gets restarted.
1544: #
1545:
1.5 foxr 1546: #
1547: # Fork and start in new session so hang-up isn't going to
1548: # happen without intent.
1549: #
1550:
1551:
1.6 foxr 1552:
1553:
1.8 foxr 1554:
1.6 foxr 1555:
1556: ShowStatus("Forming new session");
1557: my $childpid = fork;
1558: if ($childpid != 0) {
1559: sleep 4; # Give child a chacne to break to
1560: exit 0; # a new sesion.
1561: }
1.8 foxr 1562: #
1563: # Write my pid into the pid file so I can be located
1564: #
1565:
1566: ShowStatus("Parent writing pid file:");
1.23 foxr 1567: my $execdir = $perlvar{'lonDaemons'};
1.8 foxr 1568: open (PIDSAVE, ">$execdir/logs/lonc.pid");
1569: print PIDSAVE "$$\n";
1570: close(PIDSAVE);
1.6 foxr 1571:
1.17 foxr 1572:
1573:
1.6 foxr 1574: if (POSIX::setsid() < 0) {
1575: print "Could not create new session\n";
1576: exit -1;
1577: }
1.5 foxr 1578:
1579: ShowStatus("Forking node servers");
1580:
1.9 foxr 1581: Log("CRITICAL", "--------------- Starting children ---------------");
1582:
1.1 foxr 1583: my $HostIterator = LondConnection::GetHostIterator;
1584: while (! $HostIterator->end()) {
1585:
1.23 foxr 1586: my $hostentryref = $HostIterator->get();
1.1 foxr 1587: CreateChild($hostentryref->[0]);
1.26 ! foxr 1588: $HostHash{$hostentryref->[0]} = $hostentryref->[4];
1.1 foxr 1589: $HostIterator->next();
1590: }
1.12 foxr 1591: $RemoteHost = "Parent Server";
1.1 foxr 1592:
1593: # Maintain the population:
1.5 foxr 1594:
1595: ShowStatus("Parent keeping the flock");
1.1 foxr 1596:
1.10 foxr 1597: #
1598: # Set up parent signals:
1599: #
1.12 foxr 1600:
1.14 foxr 1601: $SIG{INT} = \&Terminate;
1602: $SIG{TERM} = \&Terminate;
1.13 foxr 1603: $SIG{HUP} = \&Restart;
1.14 foxr 1604: $SIG{USR1} = \&CheckKids;
1.24 foxr 1605: $SIG{USR2} = \&UpdateKids; # LonManage update request.
1.10 foxr 1606:
1.1 foxr 1607: while(1) {
1.23 foxr 1608: my $deadchild = wait();
1.1 foxr 1609: if(exists $ChildHash{$deadchild}) { # need to restart.
1.23 foxr 1610: my $deadhost = $ChildHash{$deadchild};
1.26 ! foxr 1611: delete($HostToPid{$deadhost});
1.1 foxr 1612: delete($ChildHash{$deadchild});
1.9 foxr 1613: Log("WARNING","Lost child pid= ".$deadchild.
1.1 foxr 1614: "Connected to host ".$deadhost);
1.9 foxr 1615: Log("INFO", "Restarting child procesing ".$deadhost);
1.1 foxr 1616: CreateChild($deadhost);
1617: }
1.13 foxr 1618: }
1619:
1.14 foxr 1620:
1621:
1622: =pod
1623:
1624: =head1 CheckKids
1625:
1626: Since kids do not die as easily in this implementation
1627: as the previous one, there is no need to restart the
1628: dead ones (all dead kids get restarted when they die!!)
1629: The only thing this function does is to pass USR1 to the
1630: kids so that they report their status.
1631:
1632: =cut
1633:
1634: sub CheckKids {
1635: Debug(2, "Checking status of children");
1636: my $docdir = $perlvar{'lonDocRoot'};
1637: my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
1638: my $now=time;
1639: my $local=localtime($now);
1640: print $fh "LONC status $local - parent $$ \n\n";
1.23 foxr 1641: foreach my $pid (keys %ChildHash) {
1.14 foxr 1642: Debug(2, "Sending USR1 -> $pid");
1643: kill 'USR1' => $pid; # Tell Child to report status.
1644: sleep 1; # Wait so file doesn't intermix.
1645: }
1646: }
1.24 foxr 1647:
1648: =pod
1649:
1650: =head1 UpdateKids
1651:
1.25 foxr 1652: parent's SIGUSR2 handler. This handler:
1.24 foxr 1653:
1654: =item
1655:
1656: Rereads the hosts file.
1657:
1658: =item
1659:
1660: Kills off (via sigint) children for hosts that have disappeared.
1661:
1662: =item
1663:
1664: HUP's children for hosts that already exist (this just forces a status display
1665: and resets the connection retry count for that host.
1666:
1667: =item
1668:
1669: Starts new children for hosts that have been added to the hosts.tab file since
1670: the start of the master program and maintains them.
1671:
1672: =cut
1673:
1674: sub UpdateKids {
1.25 foxr 1675: Log("INFO", "Updating connections via SIGUSR2");
1.24 foxr 1676: }
1677:
1.14 foxr 1678:
1.13 foxr 1679: =pod
1680:
1681: =head1 Restart
1682:
1683: Signal handler for HUP... all children are killed and
1684: we self restart. This is an el-cheapo way to re read
1685: the config file.
1686:
1687: =cut
1688:
1689: sub Restart {
1.23 foxr 1690: &KillThemAll; # First kill all the children.
1.13 foxr 1691: Log("CRITICAL", "Restarting");
1692: my $execdir = $perlvar{'lonDaemons'};
1693: unlink("$execdir/logs/lonc.pid");
1694: exec("$execdir/lonc");
1.10 foxr 1695: }
1.12 foxr 1696:
1697: =pod
1698:
1699: =head1 KillThemAll
1700:
1701: Signal handler that kills all children by sending them a
1.17 foxr 1702: SIGHUP. Responds to sigint and sigterm.
1.12 foxr 1703:
1704: =cut
1705:
1.10 foxr 1706: sub KillThemAll {
1.12 foxr 1707: Debug(2, "Kill them all!!");
1708: local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
1.23 foxr 1709: foreach my $pid (keys %ChildHash) {
1.12 foxr 1710: my $serving = $ChildHash{$pid};
1711: Debug(2, "Killing lonc for $serving pid = $pid");
1712: ShowStatus("Killing lonc for $serving pid = $pid");
1713: Log("CRITICAL", "Killing lonc for $serving pid = $pid");
1.17 foxr 1714: kill 'QUIT' => $pid;
1715: delete($ChildHash{$pid});
1.12 foxr 1716: }
1.14 foxr 1717: my $execdir = $perlvar{'lonDaemons'};
1718: unlink("$execdir/logs/lonc.pid");
1.17 foxr 1719:
1.1 foxr 1720: }
1.12 foxr 1721:
1.14 foxr 1722: =pod
1723:
1724: =head1 Terminate
1725:
1726: Terminate the system.
1727:
1728: =cut
1729:
1730: sub Terminate {
1731: KillThemAll;
1.17 foxr 1732: Log("CRITICAL","Master process exiting");
1733: exit 0;
1.14 foxr 1734:
1735: }
1.12 foxr 1736: =pod
1.1 foxr 1737:
1738: =head1 Theory
1.3 albertel 1739:
1740: The event class is used to build this as a single process with an
1741: event driven model. The following events are handled:
1.1 foxr 1742:
1743: =item UNIX Socket connection Received
1744:
1745: =item Request data arrives on UNIX data transfer socket.
1746:
1747: =item lond connection becomes writable.
1748:
1749: =item timer fires at 1 second intervals.
1750:
1751: All sockets are run in non-blocking mode. Timeouts managed by the timer
1752: handler prevents hung connections.
1753:
1754: Key data structures:
1755:
1.3 albertel 1756: =item RequestQueue
1757:
1758: A queue of requests received from UNIX sockets that are
1759: waiting for a chance to be forwarded on a lond connection socket.
1760:
1761: =item ActiveConnections
1762:
1763: A hash of lond connections that have transactions in process that are
1764: available to be timed out.
1765:
1766: =item ActiveTransactions
1767:
1768: A hash indexed by lond connections that contain the client reply
1769: socket for each connection that has an active transaction on it.
1770:
1771: =item IdleConnections
1772:
1773: A hash of lond connections that have no work to do. These connections
1774: can be closed if they are idle for a long enough time.
1.1 foxr 1775:
1776: =cut
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to loncnew CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom