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