--- loncom/loncnew 2003/04/29 03:24:51 1.5
+++ loncom/loncnew 2004/08/26 12:35:10 1.51
@@ -2,13 +2,12 @@
# The LearningOnline Network with CAPA
# lonc maintains the connections to remote computers
#
-# $Id: loncnew,v 1.5 2003/04/29 03:24:51 foxr Exp $
+# $Id: loncnew,v 1.51 2004/08/26 12:35:10 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
-#
-# LON-CAPA is free software; you can redistribute it and/or modify
+## LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
@@ -27,48 +26,42 @@
# http://www.lon-capa.org/
#
#
-# new lonc handles n requestors spread out bver m connections to londs.
+# new lonc handles n request out bver m connections to londs.
# This module is based on the Event class.
# Development iterations:
# - Setup basic event loop. (done)
# - Add timer dispatch. (done)
# - Add ability to accept lonc UNIX domain sockets. (done)
# - Add ability to create/negotiate lond connections (done).
-# - Add general logic for dispatching requests and timeouts.
-# - Add support for the lonc/lond requests.
-# - Add logging/status monitoring.
-# - Add Signal handling - HUP restarts. USR1 status report.
-# - Add Configuration file I/O
-# - Add Pending request processing on startup.
-# - Add management/status request interface.
+# - Add general logic for dispatching requests and timeouts. (done).
+# - Add support for the lonc/lond requests. (done).
+# - Add logging/status monitoring. (done)
+# - Add Signal handling - HUP restarts. USR1 status report. (done)
+# - Add Configuration file I/O (done).
+# - Add management/status request interface. (done)
+# - Add deferred request capability. (done)
+# - Detect transmission timeouts. (done)
+#
+use strict;
use lib "/home/httpd/lib/perl/";
-use lib "/home/foxr/newloncapa/types";
use Event qw(:DEFAULT );
use POSIX qw(:signal_h);
+use POSIX;
use IO::Socket;
use IO::Socket::INET;
use IO::Socket::UNIX;
+use IO::File;
+use IO::Handle;
use Socket;
use Crypt::IDEA;
use LONCAPA::Queue;
use LONCAPA::Stack;
use LONCAPA::LondConnection;
+use LONCAPA::LondTransaction;
use LONCAPA::Configuration;
use LONCAPA::HashIterator;
-print "Loncnew starting\n";
-
-#
-# Disable all signals we might receive from outside for now.
-#
-$SIG{QUIT} = IGNORE;
-$SIG{HUP} = IGNORE;
-$SIG{USR1} = IGNORE;
-$SIG{INT} = IGNORE;
-$SIG{CHLD} = IGNORE;
-$SIG{__DIE__} = IGNORE;
-
# Read the httpd configuration file to get perl variables
# normally set in apache modules:
@@ -80,29 +73,121 @@ my %perlvar = %{$perlvarref};
# parent and shared variables.
my %ChildHash; # by pid -> host.
+my %HostToPid; # By host -> pid.
+my %HostHash; # by loncapaname -> IP.
-my $MaxConnectionCount = 5; # Will get from config later.
+my $MaxConnectionCount = 10; # Will get from config later.
my $ClientConnection = 0; # Uniquifier for client events.
-my $DebugLevel = 5;
-my $IdleTimeout= 3600; # Wait an hour before pruning connections.
+my $DebugLevel = 0;
+my $NextDebugLevel= 2; # So Sigint can toggle this.
+my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.
+
+my $LogTransactions = 0; # When True, all transactions/replies get logged.
#
# The variables below are only used by the child processes.
#
my $RemoteHost; # Name of host child is talking to.
-my $UnixSocketDir= "/home/httpd/sockets";
+my $UnixSocketDir= $perlvar{'lonSockDir'};
my $IdleConnections = Stack->new(); # Set of idle connections
my %ActiveConnections; # Connections to the remote lond.
-my %ActiveTransactions; # Transactions in flight.
+my %ActiveTransactions; # LondTransactions in flight.
my %ActiveClients; # Serial numbers of active clients by socket.
my $WorkQueue = Queue->new(); # Queue of pending transactions.
-my $ClientQueue = Queue->new(); # Queue of clients causing xactinos.
my $ConnectionCount = 0;
my $IdleSeconds = 0; # Number of seconds idle.
-
+my $Status = ""; # Current status string.
+my $RecentLogEntry = "";
+my $ConnectionRetries=2; # Number of connection retries allowed.
+my $ConnectionRetriesLeft=2; # Number of connection retries remaining.
+my $LondVersion = "unknown"; # Version of lond we talk with.
+my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
+
+my $LongTickLength = 10000000; #Tick Frequency when Idle
+my $ShortTickLength = 1; #Tick Frequency when Active (many places in
+ # the code assume this is one)
+my $TickLength = $ShortTickLength;#number of seconds to wait until ticking
#
+# The hash below gives the HTML format for log messages
+# given a severity.
+#
+my %LogFormats;
+
+$LogFormats{"CRITICAL"} = "CRITICAL: %s";
+$LogFormats{"SUCCESS"} = "SUCCESS: %s";
+$LogFormats{"INFO"} = "INFO: %s";
+$LogFormats{"WARNING"} = "WARNING: %s";
+$LogFormats{"DEFAULT"} = " %s ";
+
+
+
+=pod
+
+=head2 LogPerm
+
+Makes an entry into the permanent log file.
+
+=cut
+sub LogPerm {
+ my $message=shift;
+ my $execdir=$perlvar{'lonDaemons'};
+ my $now=time;
+ my $local=localtime($now);
+ my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
+ print $fh "$now:$message:$local\n";
+}
+
+=pod
+
+=head2 Log
+
+Logs a message to the log file.
+Parameters:
+
+=item severity
+
+One of CRITICAL, WARNING, INFO, SUCCESS used to select the
+format string used to format the message. if the severity is
+not a defined severity the Default format string is used.
+
+=item message
+
+The base message. In addtion to the format string, the message
+will be appended to a string containing the name of our remote
+host and the time will be formatted into the message.
+
+=cut
+
+sub Log {
+
+ my ($severity, $message) = @_;
+
+ if(!$LogFormats{$severity}) {
+ $severity = "DEFAULT";
+ }
+
+ my $format = $LogFormats{$severity};
+
+ # Put the window dressing in in front of the message format:
+
+ my $now = time;
+ my $local = localtime($now);
+ my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
+ my $finalformat = $finalformat.$format."\n";
+
+ # open the file and put the result.
+
+ my $execdir = $perlvar{'lonDaemons'};
+ my $fh = IO::File->new(">>$execdir/logs/lonc.log");
+ my $msg = sprintf($finalformat, $message);
+ $RecentLogEntry = $msg;
+ print $fh $msg;
+
+
+}
+
=pod
@@ -113,14 +198,16 @@ Returns the name of the host that a sock
=cut
sub GetPeername {
- my $connection = shift;
- my $AdrFamily = shift;
+
+
+ my ($connection, $AdrFamily) = @_;
+
my $peer = $connection->peername();
my $peerport;
my $peerip;
if($AdrFamily == AF_INET) {
($peerport, $peerip) = sockaddr_in($peer);
- my $peername = gethostbyaddr($iaddr, $AdrFamily);
+ my $peername = gethostbyaddr($peerip, $AdrFamily);
return $peername;
} elsif ($AdrFamily == AF_UNIX) {
my $peerfile;
@@ -128,7 +215,6 @@ sub GetPeername {
return $peerfile;
}
}
-#----------------------------- Timer management ------------------------
=pod
=head2 Debug
@@ -138,18 +224,20 @@ Invoked to issue a debug message.
=cut
sub Debug {
- my $level = shift;
- my $message = shift;
+
+ my ($level, $message) = @_;
+
if ($level <= $DebugLevel) {
- print $message." host = ".$RemoteHost."\n";
+ Log("INFO", "-Debug- $message host = $RemoteHost");
}
}
sub SocketDump {
- my $level = shift;
- my $socket= shift;
+
+ my ($level, $socket) = @_;
+
if($level <= $DebugLevel) {
- $socket->Dump();
+ $socket->Dump(-1); # Ensure it will get dumped.
}
}
@@ -158,15 +246,46 @@ sub SocketDump {
=head2 ShowStatus
Place some text as our pid status.
+ and as what we return in a SIGUSR1
=cut
sub ShowStatus {
- my $status = shift;
- $0 = "lonc: ".$status;
+ my $state = shift;
+ my $now = time;
+ my $local = localtime($now);
+ $Status = $local.": ".$state;
+ $0='lonc: '.$state.' '.$local;
}
=pod
+=head 2 SocketTimeout
+
+ Called when an action on the socket times out. The socket is
+ destroyed and any active transaction is failed.
+
+
+=cut
+sub SocketTimeout {
+ my $Socket = shift;
+ Log("WARNING", "A socket timeout was detected");
+ Debug(0, " SocketTimeout called: ");
+ $Socket->Dump(0);
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ }
+ KillSocket($Socket); # A transaction timeout also counts as
+ # a connection failure:
+ $ConnectionRetriesLeft--;
+ if($ConnectionRetriesLeft <= 0) {
+ Log("CRITICAL", "Host marked dead: ".GetServerHost());
+ }
+
+}
+#----------------------------- Timer management ------------------------
+
+=pod
+
=head2 Tick
Invoked each timer tick.
@@ -176,40 +295,70 @@ Invoked each timer tick.
sub Tick {
my $client;
- ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);
- Debug(6, "Tick");
- Debug(6, " Current connection count: ".$ConnectionCount);
- foreach $client (keys %ActiveClients) {
- Debug(7, " Have client: with id: ".$ActiveClients{$client});
+ if($ConnectionRetriesLeft > 0) {
+ ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
+ ." Retries remaining: ".$ConnectionRetriesLeft
+ ." ($KeyMode)");
+ } else {
+ ShowStatus(GetServerHost()." >> DEAD <<");
}
# Is it time to prune connection count:
if($IdleConnections->Count() &&
($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
- $IdleSeconds++;
+ $IdleSeconds+=$TickLength;
if($IdleSeconds > $IdleTimeout) { # Prune a connection...
- $Socket = $IdleConnections->pop();
- KillSocket($Socket, 0);
+ my $Socket = $IdleConnections->pop();
+ KillSocket($Socket);
+ if ($IdleConnections->Count() == 0) {
+ &SetupTimer($LongTickLength);
+ }
}
} else {
$IdleSeconds = 0; # Reset idle count if not idle.
}
+ #
+ # For each inflight transaction, tick down its timeout counter.
+ #
+ foreach my $item (keys %ActiveConnections) {
+ my $State = $ActiveConnections{$item}->data->GetState();
+ if ($State ne 'Idle') {
+ Debug(5,"Ticking Socket $State $item");
+ $ActiveConnections{$item}->data->Tick();
+ }
+ }
# Do we have work in the queue, but no connections to service them?
# If so, try to make some new connections to get things going again.
#
my $Requests = $WorkQueue->Count();
- if (($ConnectionCount == 0) && ($Requests > 0)) {
- my $Connections = ($Requests <= $MaxConnectionCount) ?
- $Requests : $MaxConnectionCount;
- Debug(1,"Work but no connections, starting ".$Connections." of them");
- for ($i =0; $i < $Connections; $i++) {
- MakeLondConnection();
+ if (($ConnectionCount == 0) && ($Requests > 0)) {
+ if ($ConnectionRetriesLeft > 0) {
+ my $Connections = ($Requests <= $MaxConnectionCount) ?
+ $Requests : $MaxConnectionCount;
+ Debug(5,"Work but no connections, start ".$Connections." of them");
+ my $successCount = 0;
+ for (my $i =0; $i < $Connections; $i++) {
+ $successCount += MakeLondConnection();
+ }
+ if($successCount == 0) { # All connections failed:
+ Debug(5,"Work in queue failed to make any connectiouns\n");
+ EmptyQueue(); # Fail pending transactions with con_lost.
+ CloseAllLondConnections(); # Should all be closed but....
+ }
+ } else {
+ ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
+ Debug(5,"Work in queue, but gave up on connections..flushing\n");
+ EmptyQueue(); # Connections can't be established.
+ CloseAllLondConnections(); # Should all already be closed but...
}
}
+ if ($ConnectionCount == 0) {
+ $KeyMode = "";
+ }
}
=pod
@@ -228,9 +377,13 @@ Trigger disconnections of idle sockets.
=cut
+my $timer;
sub SetupTimer {
- Debug(6, "SetupTimer");
- Event->timer(interval => 1, debug => 1, cb => \&Tick );
+ my ($newLength)=@_;
+ Debug(6, "SetupTimer $TickLength->$newLength");
+ $TickLength=$newLength;
+ if ($timer) { $timer->cancel; }
+ $timer=Event->timer(interval => $TickLength, cb => \&Tick );
}
=pod
@@ -250,24 +403,22 @@ long enough, it will be shut down and re
sub ServerToIdle {
my $Socket = shift; # Get the socket.
+ $KeyMode = $Socket->{AuthenticationMode};
+ delete($ActiveTransactions{$Socket}); # Server has no transaction
- &Debug(6, "Server to idle");
+ &Debug(5, "Server to idle");
# If there's work to do, start the transaction:
- $reqdata = $WorkQueue->dequeue();
- Debug(9, "Queue gave request data: ".$reqdata);
- unless($reqdata eq undef) {
- my $unixSocket = $ClientQueue->dequeue();
- &Debug(6, "Starting new work request");
- &Debug(7, "Request: ".$reqdata);
-
- &StartRequest($Socket, $unixSocket, $reqdata);
+ my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
+ if ($reqdata ne undef) {
+ Debug(5, "Queue gave request data: ".$reqdata->getRequest());
+ &StartRequest($Socket, $reqdata);
+
} else {
# There's no work waiting, so push the server to idle list.
- &Debug(8, "No new work requests, server connection going idle");
- delete($ActiveTransactions{$Socket});
+ &Debug(5, "No new work requests, server connection going idle");
$IdleConnections->push($Socket);
}
}
@@ -302,51 +453,61 @@ sub ClientWritable {
&Debug(6, "ClientWritable writing".$Data);
&Debug(9, "Socket is: ".$Socket);
- my $result = $Socket->send($Data, 0);
-
- # $result undefined: the write failed.
- # otherwise $result is the number of bytes written.
- # Remove that preceding string from the data.
- # If the resulting data is empty, destroy the watcher
- # and set up a read event handler to accept the next
- # request.
-
- &Debug(9,"Send result is ".$result." Defined: ".defined($result));
- if(defined($result)) {
- &Debug(9, "send result was defined");
- if($result == length($Data)) { # Entire string sent.
- &Debug(9, "ClientWritable data all written");
- $Watcher->cancel();
- #
- # Set up to read next request from socket:
-
- my $descr = sprintf("Connection to lonc client %d",
- $ActiveClients{$Socket});
- Event->io(cb => \&ClientRequest,
- poll => 'r',
- desc => $descr,
- data => "",
- fd => $Socket);
-
- } else { # Partial string sent.
- $Watcher->data(substr($Data, $result));
- }
+ if($Socket->connected) {
+ my $result = $Socket->send($Data, 0);
- } else { # Error of some sort...
-
- # Some errnos are possible:
- my $errno = $!;
- if($errno == POSIX::EWOULDBLOCK ||
- $errno == POSIX::EAGAIN ||
- $errno == POSIX::EINTR) {
- # No action taken?
- } else { # Unanticipated errno.
- &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
- $Watcher->cancel; # Stop the watcher.
- $Socket->shutdown(2); # Kill connection
- $Socket->close(); # Close the socket.
- }
+ # $result undefined: the write failed.
+ # otherwise $result is the number of bytes written.
+ # Remove that preceding string from the data.
+ # If the resulting data is empty, destroy the watcher
+ # and set up a read event handler to accept the next
+ # request.
+ &Debug(9,"Send result is ".$result." Defined: ".defined($result));
+ if($result ne undef) {
+ &Debug(9, "send result was defined");
+ if($result == length($Data)) { # Entire string sent.
+ &Debug(9, "ClientWritable data all written");
+ $Watcher->cancel();
+ #
+ # Set up to read next request from socket:
+
+ my $descr = sprintf("Connection to lonc client %d",
+ $ActiveClients{$Socket});
+ Event->io(cb => \&ClientRequest,
+ poll => 'r',
+ desc => $descr,
+ data => "",
+ fd => $Socket);
+
+ } else { # Partial string sent.
+ $Watcher->data(substr($Data, $result));
+ if($result == 0) { # client hung up on us!!
+ Log("INFO", "lonc pipe client hung up on us!");
+ $Watcher->cancel;
+ $Socket->shutdown(2);
+ $Socket->close();
+ }
+ }
+
+ } else { # Error of some sort...
+
+ # Some errnos are possible:
+ my $errno = $!;
+ if($errno == POSIX::EWOULDBLOCK ||
+ $errno == POSIX::EAGAIN ||
+ $errno == POSIX::EINTR) {
+ # No action taken?
+ } else { # Unanticipated errno.
+ &Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
+ $Watcher->cancel; # Stop the watcher.
+ $Socket->shutdown(2); # Kill connection
+ $Socket->close(); # Close the socket.
+ }
+
+ }
+ } else {
+ $Watcher->cancel(); # A delayed request...just cancel.
}
}
@@ -367,18 +528,53 @@ Parameters:
Socket on which the lond transaction occured. This is a
LondConnection. The data received is in the TransactionReply member.
-=item Client
+=item Transaction
-Unix domain socket open on the ultimate client.
+The transaction that is being completed.
=cut
sub CompleteTransaction {
- &Debug(6,"Complete transaction");
- my $Socket = shift;
- my $Client = shift;
+ &Debug(5,"Complete transaction");
- my $data = $Socket->GetReply(); # Data to send.
+ my ($Socket, $Transaction) = @_;
+
+ if (!$Transaction->isDeferred()) { # Normal transaction
+ my $data = $Socket->GetReply(); # Data to send.
+ if($LogTransactions) {
+ Log("SUCCESS", "Reply from lond: '$data'");
+ }
+ StartClientReply($Transaction, $data);
+ } else { # Delete deferred transaction file.
+ Log("SUCCESS", "A delayed transaction was completed");
+ LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
+ unlink $Transaction->getFile();
+ }
+}
+
+=pod
+
+=head1 StartClientReply
+
+ Initiates a reply to a client where the reply data is a parameter.
+
+=head2 parameters:
+
+=item Transaction
+
+ The transaction for which we are responding to the client.
+
+=item data
+
+ The data to send to apached client.
+
+=cut
+
+sub StartClientReply {
+
+ my ($Transaction, $data) = @_;
+
+ my $Client = $Transaction->getClient();
&Debug(8," Reply was: ".$data);
my $Serial = $ActiveClients{$Client};
@@ -390,35 +586,72 @@ sub CompleteTransaction {
cb => \&ClientWritable,
data => $data);
}
+
=pod
+
=head2 FailTransaction
Finishes a transaction with failure because the associated lond socket
- disconnected. It is up to our client to retry if desired.
+ disconnected. There are two possibilities:
+ - The transaction is deferred: in which case we just quietly
+ delete the transaction since there is no client connection.
+ - The transaction is 'live' in which case we initiate the sending
+ of "con_lost" to the client.
+
+Deleting the transaction means killing it from the %ActiveTransactions hash.
Parameters:
=item client
- The UNIX domain socket open on our client.
+ The LondTransaction we are failing.
+
=cut
sub FailTransaction {
- my $client = shift;
+ my $transaction = shift;
+ Log("WARNING", "Failing transaction ".$transaction->getRequest());
+ Debug(1, "Failing transaction: ".$transaction->getRequest());
+ if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
+ my $client = $transaction->getClient();
+ Debug(1," Replying con_lost to ".$transaction->getRequest());
+ StartClientReply($transaction, "con_lost\n");
+ }
- &Debug(8, "Failing transaction due to disconnect");
- my $Serial = $ActiveClients{$client};
- my $desc = sprintf("Connection to lonc client %d", $Serial);
- my $data = "error: Connection to lond lost\n";
-
- Event->io(fd => $client,
- poll => "w",
- desc => $desc,
- cb => \&ClientWritable,
- data => $data);
+}
+
+=pod
+=head1 EmptyQueue
+ Fails all items in the work queue with con_lost.
+ Note that each item in the work queue is a transaction.
+
+=cut
+sub EmptyQueue {
+ $ConnectionRetriesLeft--; # Counts as connection failure too.
+ while($WorkQueue->Count()) {
+ my $request = $WorkQueue->dequeue(); # This is a transaction
+ FailTransaction($request);
+ }
+}
+
+=pod
+
+=head2 CloseAllLondConnections
+
+Close all connections open on lond prior to exit e.g.
+
+=cut
+sub CloseAllLondConnections {
+ foreach my $Socket (keys %ActiveConnections) {
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ }
+ KillSocket($Socket);
+ }
}
+=cut
=pod
@@ -444,22 +677,31 @@ nonzero if we are allowed to create a ne
=cut
sub KillSocket {
my $Socket = shift;
- my $Restart= shift;
- # If the socket came from the active connection set, delete it.
- # otherwise it came from the idle set and has already been destroyed:
+ Log("WARNING", "Shutting down a socket");
+ $Socket->Shutdown();
+
+ # If the socket came from the active connection set,
+ # delete its transaction... note that FailTransaction should
+ # already have been called!!!
+ # otherwise it came from the idle set.
+ #
if(exists($ActiveTransactions{$Socket})) {
delete ($ActiveTransactions{$Socket});
}
if(exists($ActiveConnections{$Socket})) {
delete($ActiveConnections{$Socket});
+ $ConnectionCount--;
+ if ($ConnectionCount < 0) { $ConnectionCount = 0; }
}
- $ConnectionCount--;
- if( ($ConnectionCount = 0) && ($Restart)) {
- MakeLondConnection();
+ # If the connection count has gone to zero and there is work in the
+ # work queue, the work all gets failed with con_lost.
+ #
+ if($ConnectionCount == 0) {
+ EmptyQueue();
+ CloseAllLondConnections; # Should all already be closed but...
}
-
}
=pod
@@ -484,6 +726,17 @@ The connection must echo the challenge b
The challenge has been replied to. The we are receiveing the
'ok' from the partner.
+=head3 State=ReadingVersionString
+
+We have requested the lond version and are reading the
+version back. Upon completion, we'll store the version away
+for future use(?).
+
+=head3 State=HostSet
+
+We have selected the domain name of our peer (multhomed hosts)
+and are getting the reply (presumably ok) back.
+
=head3 State=RequestingKey
The ok has been received and we need to send the request for
@@ -521,27 +774,34 @@ transaction is in progress, the socket a
=cut
sub LondReadable {
+
my $Event = shift;
my $Watcher = $Event->w;
my $Socket = $Watcher->data;
my $client = undef;
+ &Debug(6,"LondReadable called state = ".$Socket->GetState());
+
my $State = $Socket->GetState(); # All action depends on the state.
- &Debug(6,"LondReadable called state = ".$State);
SocketDump(6, $Socket);
+ my $status = $Socket->Readable();
- if($Socket->Readable() != 0) {
- # bad return from socket read. Currently this means that
+ &Debug(2, "Socket->Readable returned: $status");
+
+ if($status != 0) {
+ # bad return from socket read. Currently this means that
# The socket has become disconnected. We fail the transaction.
+ Log("WARNING",
+ "Lond connection lost.");
if(exists($ActiveTransactions{$Socket})) {
- Debug(3,"Lond connection lost failing transaction");
FailTransaction($ActiveTransactions{$Socket});
}
$Watcher->cancel();
- KillSocket($Socket, 1);
+ KillSocket($Socket);
+ $ConnectionRetriesLeft--; # Counts as connection failure
return;
}
SocketDump(6,$Socket);
@@ -549,40 +809,70 @@ sub LondReadable {
$State = $Socket->GetState(); # Update in case of transition.
&Debug(6, "After read, state is ".$State);
- if($State eq "Initialized") {
+ if($State eq "Initialized") {
} elsif ($State eq "ChallengeReceived") {
# The challenge must be echoed back; The state machine
# in the connection takes care of setting that up. Just
# need to transition to writable:
-
- $Watcher->poll("w");
+
$Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
} elsif ($State eq "ChallengeReplied") {
+ } elsif ($State eq "RequestingVersion") {
+ # Need to ask for the version... that is writiability:
+
+ $Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
+
+ } elsif ($State eq "ReadingVersionString") {
+ # Read the rest of the version string...
+ } elsif ($State eq "SetHost") {
+ # Need to request the actual domain get set...
+
+ $Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
+ } elsif ($State eq "HostSet") {
+ # Reading the 'ok' from the peer.
} elsif ($State eq "RequestingKey") {
# The ok was received. Now we need to request the key
# That requires us to be writable:
- $Watcher->poll("w");
$Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
} elsif ($State eq "ReceivingKey") {
} elsif ($State eq "Idle") {
+
+ # This is as good a spot as any to get the peer version
+ # string:
+
+ if($LondVersion eq "unknown") {
+ $LondVersion = $Socket->PeerVersion();
+ Log("INFO", "Connected to lond version: $LondVersion");
+ }
# If necessary, complete a transaction and then go into the
# idle queue.
+ # Note that a trasition to idle indicates a live lond
+ # on the other end so reset the connection retries.
+ #
+ $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
+ $Watcher->cancel();
if(exists($ActiveTransactions{$Socket})) {
- Debug(8,"Completing transaction!!");
+ Debug(5,"Completing transaction!!");
CompleteTransaction($Socket,
$ActiveTransactions{$Socket});
+ } else {
+ Log("SUCCESS", "Connection ".$ConnectionCount." to "
+ .$RemoteHost." now ready for action");
}
- $Watcher->cancel();
ServerToIdle($Socket); # Next work unit or idle.
-
+
} elsif ($State eq "SendingRequest") {
# We need to be writable for this and probably don't belong
# here inthe first place.
@@ -595,7 +885,7 @@ sub LondReadable {
} else {
- # Invalid state.
+ # Invalid state.
Debug(4, "Invalid state in LondReadable");
}
}
@@ -664,102 +954,112 @@ is the socket on which to return a reply
sub LondWritable {
my $Event = shift;
my $Watcher = $Event->w;
- my @data = $Watcher->data;
- Debug(6,"LondWritable State = ".$State." data has ".@data." elts.\n");
+ my $Socket = $Watcher->data;
+ my $State = $Socket->GetState();
- my $Socket = $data[0]; # I know there's at least a socket.
+ Debug(6,"LondWritable State = ".$State."\n");
+
# Figure out what to do depending on the state of the socket:
- my $State = $Socket->GetState();
SocketDump(6,$Socket);
+ # If the socket is writable, we must always write.
+ # Only by writing will we undergo state transitions.
+ # Old logic wrote in state specific code below, however
+ # That forces us at least through another invocation of
+ # this function after writability is possible again.
+ # This logic also factors out common code for handling
+ # write failures... in all cases, write failures
+ # Kill the socket.
+ # This logic makes the branches of the >big< if below
+ # so that the writing states are actually NO-OPs.
+
+ if ($Socket->Writable() != 0) {
+ # The write resulted in an error.
+ # We'll treat this as if the socket got disconnected:
+ Log("WARNING", "Connection to ".$RemoteHost.
+ " has been disconnected");
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ }
+ $Watcher->cancel();
+ KillSocket($Socket);
+ return;
+ }
+
+
+
if ($State eq "Connected") {
- if ($Socket->Writable() != 0) {
- # The write resulted in an error.
- # We'll treat this as if the socket got disconnected:
-
- $Watcher->cancel();
- KillSocket($Socket, 1);
- return;
- }
# "init" is being sent...
-
-
+
} elsif ($State eq "Initialized") {
# Now that init was sent, we switch
# to watching for readability:
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
-
+ $Watcher->poll("r");
+
} elsif ($State eq "ChallengeReceived") {
# We received the challenge, now we
# are echoing it back. This is a no-op,
# we're waiting for the state to change
- if($Socket->Writable() != 0) {
-
- $Watcher->cancel();
- KillSocket($Socket, 1);
- return;
- }
-
} elsif ($State eq "ChallengeReplied") {
# The echo was sent back, so we switch
# to watching readability.
+ $Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
+ } elsif ($State eq "RequestingVersion") {
+ # Sending the peer a version request...
+
+ } elsif ($State eq "ReadingVersionString") {
+ # Transition to read since we have sent the
+ # version command and now just need to read the
+ # version string from the peer:
+
+ $Watcher->cb(\&LondReadable);
$Watcher->poll("r");
+
+ } elsif ($State eq "SetHost") {
+ # Setting the remote domain...
+
+ } elsif ($State eq "HostSet") {
+ # Back to readable to get the ok.
+
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
+
} elsif ($State eq "RequestingKey") {
# At this time we're requesting the key.
# again, this is essentially a no-op.
- # we'll write the next chunk until the
- # state changes.
-
- if($Socket->Writable() != 0) {
- # Write resulted in an error.
-
- $Watcher->cancel();
- KillSocket($Socket, 1);
- return;
- }
} elsif ($State eq "ReceivingKey") {
# Now we need to wait for the key
# to come back from the peer:
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
} elsif ($State eq "SendingRequest") {
+
# At this time we are sending a request to the
# peer... write the next chunk:
- if($Socket->Writable() != 0) {
-
- if(exists($ActiveTransactions{$Socket})) {
- Debug(3, "Lond connection lost, failing transactions");
- FailTransaction($ActiveTransactions{$Socket});
- }
- $Watcher->cancel();
- KillSocket($Socket, 1);
- return;
-
- }
} elsif ($State eq "ReceivingReply") {
# The send has completed. Wait for the
# data to come in for a reply.
Debug(8,"Writable sent request/receiving reply");
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
} else {
# Control only passes here on an error:
@@ -771,6 +1071,34 @@ sub LondWritable {
}
}
+=pod
+
+=cut
+sub QueueDelayed {
+ Debug(3,"QueueDelayed called");
+
+ my $path = "$perlvar{'lonSockDir'}/delayed";
+
+ Debug(4, "Delayed path: ".$path);
+ opendir(DIRHANDLE, $path);
+
+ my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
+ closedir(DIRHANDLE);
+ my $dfname;
+ my $reqfile;
+ foreach $dfname (sort @alldelayed) {
+ $reqfile = "$path/$dfname";
+ Debug(4, "queueing ".$reqfile);
+ my $Handle = IO::File->new($reqfile);
+ my $cmd = <$Handle>;
+ chomp $cmd; # There may or may not be a newline...
+ $cmd = $cmd."\n"; # now for sure there's exactly one newline.
+ my $Transaction = LondTransaction->new($cmd);
+ $Transaction->SetDeferred($reqfile);
+ QueueTransaction($Transaction);
+ }
+
+}
=pod
@@ -791,30 +1119,41 @@ sub MakeLondConnection {
my $Connection = LondConnection->new(&GetServerHost(),
&GetServerPort());
- if($Connection == undef) { # Needs to be more robust later.
- Debug(0,"Failed to make a connection with lond.");
+ if($Connection eq undef) { # Needs to be more robust later.
+ Log("CRITICAL","Failed to make a connection with lond.");
+ $ConnectionRetriesLeft--;
+ return 0; # Failure.
} else {
+
# The connection needs to have writability
# monitored in order to send the init sequence
# that starts the whole authentication/key
# exchange underway.
#
my $Socket = $Connection->GetSocket();
- if($Socket == undef) {
+ if($Socket eq undef) {
die "did not get a socket from the connection";
} else {
&Debug(9,"MakeLondConnection got socket: ".$Socket);
}
-
- $event = Event->io(fd => $Socket,
+ $Connection->SetTimeoutCallback(\&SocketTimeout);
+
+ my $event = Event->io(fd => $Socket,
poll => 'w',
cb => \&LondWritable,
- data => ($Connection, undef),
+ data => $Connection,
desc => 'Connection to lond server');
$ActiveConnections{$Connection} = $event;
$ConnectionCount++;
+ Debug(4, "Connection count = ".$ConnectionCount);
+ if($ConnectionCount == 1) { # First Connection:
+ QueueDelayed;
+ }
+ Log("SUCESS", "Created connection ".$ConnectionCount
+ ." to host ".GetServerHost());
+ return 1; # Return success.
}
}
@@ -845,18 +1184,18 @@ The text of the request to send.
=cut
sub StartRequest {
- my $Lond = shift;
- my $Client = shift;
- my $Request = shift;
+
+ my ($Lond, $Request) = @_;
- Debug(6, "StartRequest: ".$Request);
+ Debug(6, "StartRequest: ".$Request->getRequest());
my $Socket = $Lond->GetSocket();
- $ActiveTransactions{$Lond} = $Client; # Socket to relay to client.
+ $Request->Activate($Lond);
+ $ActiveTransactions{$Lond} = $Request;
- $Lond->InitiateTransaction($Request);
- $event = Event->io(fd => $Lond->GetSocket(),
+ $Lond->InitiateTransaction($Request->getRequest());
+ my $event = Event->io(fd => $Socket,
poll => "w",
cb => \&LondWritable,
data => $Lond,
@@ -887,23 +1226,33 @@ data to send to the lond.
=cut
sub QueueTransaction {
- my $requestSocket = shift;
- my $requestData = shift;
- Debug(6,"QueueTransaction: ".$requestData);
+ my $requestData = shift; # This is a LondTransaction.
+ my $cmd = $requestData->getRequest();
+
+ Debug(6,"QueueTransaction: ".$cmd);
my $LondSocket = $IdleConnections->pop();
if(!defined $LondSocket) { # Need to queue request.
- Debug(8,"Must queue...");
- $ClientQueue->enqueue($requestSocket);
+ Debug(5,"Must queue...");
$WorkQueue->enqueue($requestData);
if($ConnectionCount < $MaxConnectionCount) {
- Debug(4,"Starting additional lond connection");
- MakeLondConnection();
+ if($ConnectionRetriesLeft > 0) {
+ Debug(5,"Starting additional lond connection");
+ if(MakeLondConnection() == 0) {
+ EmptyQueue(); # Fail transactions, can't make connection.
+ CloseAllLondConnections; # Should all be closed but...
+ }
+ &SetupTimer($ShortTickLength);
+ } else {
+ ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
+ EmptyQueue(); # It's worse than that ... he's dead Jim.
+ CloseAllLondConnections; # Should all be closed but..
+ }
}
} else { # Can start the request:
Debug(8,"Can start...");
- StartRequest($LondSocket, $requestSocket, $requestData);
+ StartRequest($LondSocket, $requestData);
}
}
@@ -912,7 +1261,6 @@ sub QueueTransaction {
=pod
=head2 ClientRequest
-
Callback that is called when data can be read from the UNIX domain
socket connecting us with an apache server process.
@@ -931,19 +1279,31 @@ sub ClientRequest {
my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
Debug(8, "rcv: data length = ".length($thisread)
." read =".$thisread);
- unless (defined $rv && length($thisread)) {
+ unless (defined $rv && length($thisread)) {
# Likely eof on socket.
Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
close($socket);
$watcher->cancel();
delete($ActiveClients{$socket});
+ return;
}
Debug(8,"Data: ".$data." this read: ".$thisread);
$data = $data.$thisread; # Append new data.
$watcher->data($data);
- if($data =~ /(.*\n)/) { # Request entirely read.
+ if($data =~ /\n$/) { # Request entirely read.
+ if($data eq "close_connection_exit\n") {
+ Log("CRITICAL",
+ "Request Close Connection ... exiting");
+ CloseAllLondConnections();
+ exit;
+ }
Debug(8, "Complete transaction received: ".$data);
- QueueTransaction($socket, $data);
+ if($LogTransactions) {
+ Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
+ }
+ my $Transaction = LondTransaction->new($data);
+ $Transaction->SetClient($socket);
+ QueueTransaction($Transaction);
$watcher->cancel(); # Done looking for input data.
}
@@ -1005,7 +1365,7 @@ Returns the host whose lond we talk with
=cut
-sub GetServerHost { # Stub - get this from config.
+sub GetServerHost {
return $RemoteHost; # Setup by the fork.
}
@@ -1017,7 +1377,7 @@ Returns the lond port number.
=cut
-sub GetServerPort { # Stub - get this from config.
+sub GetServerPort {
return $perlvar{londPort};
}
@@ -1038,7 +1398,7 @@ sub SetupLoncListener {
my $socket;
my $SocketName = GetLoncSocketPath();
unlink($SocketName);
- unless ($socket = IO::Socket::UNIX->new(Local => $SocketName,
+ unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
Listen => 10,
Type => SOCK_STREAM)) {
die "Failed to create a lonc listner socket";
@@ -1049,8 +1409,102 @@ sub SetupLoncListener {
fd => $socket);
}
+#
+# Toggle transaction logging.
+# Implicit inputs:
+# LogTransactions
+# Implicit Outputs:
+# LogTransactions
+sub ToggleTransactionLogging {
+ print STDERR "Toggle transaction logging...\n";
+ if(!$LogTransactions) {
+ $LogTransactions = 1;
+ } else {
+ $LogTransactions = 0;
+ }
+
+
+ Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
+}
+
+=pod
+
+=head2 ChildStatus
+
+Child USR1 signal handler to report the most recent status
+into the status file.
+
+We also use this to reset the retries count in order to allow the
+client to retry connections with a previously dead server.
+=cut
+
+sub ChildStatus {
+ my $event = shift;
+ my $watcher = $event->w;
+
+ Debug(2, "Reporting child status because : ".$watcher->data);
+ my $docdir = $perlvar{'lonDocRoot'};
+ my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
+ print $fh $$."\t".$RemoteHost."\t".$Status."\t".
+ $RecentLogEntry."\n";
+ #
+ # Write out information about each of the connections:
+ #
+ if ($DebugLevel > 2) {
+ print $fh "Active connection statuses: \n";
+ my $i = 1;
+ print STDERR "================================= Socket Status Dump:\n";
+ foreach my $item (keys %ActiveConnections) {
+ my $Socket = $ActiveConnections{$item}->data;
+ my $state = $Socket->GetState();
+ print $fh "Connection $i State: $state\n";
+ print STDERR "---------------------- Connection $i \n";
+ $Socket->Dump(-1); # Ensure it gets dumped..
+ $i++;
+ }
+ }
+ $ConnectionRetriesLeft = $ConnectionRetries;
+}
+
=pod
+=head2 SignalledToDeath
+
+Called in response to a signal that causes a chid process to die.
+
+=cut
+
+
+sub SignalledToDeath {
+ my $event = shift;
+ my $watcher= $event->w;
+
+ Debug(2,"Signalled to death! via ".$watcher->data);
+ my ($signal) = $watcher->data;
+ chomp($signal);
+ Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
+ ."died through "."\"$signal\"");
+ LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
+ ."\"$signal\"");
+ exit 0;
+
+}
+
+=head2 ToggleDebug
+
+This sub toggles trace debugging on and off.
+
+=cut
+
+sub ToggleDebug {
+ my $Current = $DebugLevel;
+ $DebugLevel = $NextDebugLevel;
+ $NextDebugLevel = $Current;
+
+ Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
+
+}
+
=head2 ChildProcess
This sub implements a child process for a single lonc daemon.
@@ -1059,18 +1513,27 @@ This sub implements a child process for
sub ChildProcess {
- print "Loncnew\n";
- # For now turn off signals.
-
- $SIG{QUIT} = IGNORE;
- $SIG{HUP} = IGNORE;
- $SIG{USR1} = IGNORE;
- $SIG{INT} = IGNORE;
- $SIG{CHLD} = IGNORE;
- $SIG{__DIE__} = IGNORE;
+ #
+ # Signals must be handled by the Event framework...
+#
+
+ Event->signal(signal => "QUIT",
+ cb => \&SignalledToDeath,
+ data => "QUIT");
+ Event->signal(signal => "HUP",
+ cb => \&ChildStatus,
+ data => "HUP");
+ Event->signal(signal => "USR1",
+ cb => \&ChildStatus,
+ data => "USR1");
+ Event->signal(signal => "USR2",
+ cb => \&ToggleTransactionLogging);
+ Event->signal(signal => "INT",
+ cb => \&ToggleDebug,
+ data => "INT");
- SetupTimer();
+ SetupTimer($LongTickLength);
SetupLoncListener();
@@ -1080,12 +1543,9 @@ sub ChildProcess {
# Setup the initial server connection:
- &MakeLondConnection();
+ # &MakeLondConnection(); // let first work requirest do it.
+
- if($ConnectionCount == 0) {
- Debug(1,"Could not make initial connection..\n");
- Debug(1,"Will retry when there's work to do\n");
- }
Debug(9,"Entering event loop");
my $ret = Event::loop(); # Start the main event loop.
@@ -1096,16 +1556,23 @@ sub ChildProcess {
# Create a new child for host passed in:
sub CreateChild {
+ my $sigset = POSIX::SigSet->new(SIGINT);
+ sigprocmask(SIG_BLOCK, $sigset);
my $host = shift;
$RemoteHost = $host;
- Debug(3, "Forking off child for ".$RemoteHost);
- sleep(5);
- $pid = fork;
+ Log("CRITICAL", "Forking server for ".$host);
+ my $pid = fork;
if($pid) { # Parent
- $ChildHash{$pid} = $RemoteHost;
+ $RemoteHost = "Parent";
+ $ChildHash{$pid} = $host;
+ $HostToPid{$host}= $pid;
+ sigprocmask(SIG_UNBLOCK, $sigset);
+
} else { # child.
ShowStatus("Connected to ".$RemoteHost);
- ChildProcess;
+ $SIG{INT} = 'DEFAULT';
+ sigprocmask(SIG_UNBLOCK, $sigset);
+ ChildProcess; # Does not return.
}
}
@@ -1125,37 +1592,270 @@ sub CreateChild {
#
+
+
+
+
+ShowStatus("Forming new session");
+my $childpid = fork;
+if ($childpid != 0) {
+ sleep 4; # Give child a chacne to break to
+ exit 0; # a new sesion.
+}
+#
+# Write my pid into the pid file so I can be located
+#
+
ShowStatus("Parent writing pid file:");
-$execdir = $perlvar{'lonDaemons'};
+my $execdir = $perlvar{'lonDaemons'};
open (PIDSAVE, ">$execdir/logs/lonc.pid");
print PIDSAVE "$$\n";
close(PIDSAVE);
+
+
+if (POSIX::setsid() < 0) {
+ print "Could not create new session\n";
+ exit -1;
+}
+
ShowStatus("Forking node servers");
+Log("CRITICAL", "--------------- Starting children ---------------");
+
+LondConnection::ReadConfig; # Read standard config files.
my $HostIterator = LondConnection::GetHostIterator;
while (! $HostIterator->end()) {
- $hostentryref = $HostIterator->get();
+ my $hostentryref = $HostIterator->get();
CreateChild($hostentryref->[0]);
+ $HostHash{$hostentryref->[0]} = $hostentryref->[4];
$HostIterator->next();
}
+$RemoteHost = "Parent Server";
# Maintain the population:
ShowStatus("Parent keeping the flock");
+#
+# Set up parent signals:
+#
+
+$SIG{INT} = \&Terminate;
+$SIG{TERM} = \&Terminate;
+$SIG{HUP} = \&Restart;
+$SIG{USR1} = \&CheckKids;
+$SIG{USR2} = \&UpdateKids; # LonManage update request.
+
while(1) {
- $deadchild = wait();
+ my $deadchild = wait();
if(exists $ChildHash{$deadchild}) { # need to restart.
- $deadhost = $ChildHash{$deadchild};
+ my $deadhost = $ChildHash{$deadchild};
+ delete($HostToPid{$deadhost});
delete($ChildHash{$deadchild});
- Debug(4,"Lost child pid= ".$deadchild.
+ Log("WARNING","Lost child pid= ".$deadchild.
"Connected to host ".$deadhost);
+ Log("INFO", "Restarting child procesing ".$deadhost);
CreateChild($deadhost);
}
}
+
+
+=pod
+
+=head1 CheckKids
+
+ Since kids do not die as easily in this implementation
+as the previous one, there is no need to restart the
+dead ones (all dead kids get restarted when they die!!)
+The only thing this function does is to pass USR1 to the
+kids so that they report their status.
+
+=cut
+
+sub CheckKids {
+ Debug(2, "Checking status of children");
+ my $docdir = $perlvar{'lonDocRoot'};
+ my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
+ my $now=time;
+ my $local=localtime($now);
+ print $fh "LONC status $local - parent $$ \n\n";
+ foreach my $pid (keys %ChildHash) {
+ Debug(2, "Sending USR1 -> $pid");
+ kill 'USR1' => $pid; # Tell Child to report status.
+ sleep 1; # Wait so file doesn't intermix.
+ }
+}
+
+=pod
+
+=head1 UpdateKids
+
+parent's SIGUSR2 handler. This handler:
+
+=item
+
+Rereads the hosts file.
+
+=item
+
+Kills off (via sigint) children for hosts that have disappeared.
+
+=item
+
+QUITs children for hosts that already exist (this just forces a status display
+and resets the connection retry count for that host.
+
+=item
+
+Starts new children for hosts that have been added to the hosts.tab file since
+the start of the master program and maintains them.
+
+=cut
+
+sub UpdateKids {
+
+ Log("INFO", "Updating connections via SIGUSR2");
+
+ # Just in case we need to kill our own lonc, we wait a few seconds to
+ # give it a chance to receive and relay lond's response to the
+ # re-init command.
+ #
+
+ sleep(2); # Wait a couple of seconds.
+
+ my %hosts; # Indexed by loncapa hostname, value=ip.
+
+ # Need to re-read the host table:
+
+
+ LondConnection::ReadConfig();
+ my $I = LondConnection::GetHostIterator;
+ while (! $I->end()) {
+ my $item = $I->get();
+ $hosts{$item->[0]} = $item->[4];
+ $I->next();
+ }
+
+ # The logic below is written for clarity not for efficiency.
+ # Since I anticipate that this function is only rarely called, that's
+ # appropriate. There are certainly ways to combine the loops below,
+ # and anyone wishing to obscure the logic is welcome to go for it.
+ # Note that we don't re-direct sigchild. Instead we do what's needed
+ # to the data structures that keep track of children to ensure that
+ # when sigchild is honored, no new child is born.
+ #
+
+ # For each existing child; if it's host doesn't exist, kill the child.
+
+ foreach my $child (keys %ChildHash) {
+ my $oldhost = $ChildHash{$child};
+ if (!(exists $hosts{$oldhost})) {
+ Log("CRITICAL", "Killing child for $oldhost host no longer exists");
+ delete $ChildHash{$child};
+ delete $HostToPid{$oldhost};
+ kill 'QUIT' => $child;
+ }
+ }
+ # For each remaining existing child; if it's host's ip has changed,
+ # Restart the child on the new IP.
+
+ foreach my $child (keys %ChildHash) {
+ my $oldhost = $ChildHash{$child};
+ my $oldip = $HostHash{$oldhost};
+ if ($hosts{$oldhost} ne $oldip) {
+
+ # kill the old child.
+
+ Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
+ delete $ChildHash{$child};
+ delete $HostToPid{$oldhost};
+ kill 'QUIT' => $child;
+
+ # Do the book-keeping needed to start a new child on the
+ # new ip.
+
+ $HostHash{$oldhost} = $hosts{$oldhost};
+ CreateChild($oldhost);
+ }
+ }
+ # Finally, for each new host, not in the host hash, create a
+ # enter the host and create a new child.
+ # Force a status display of any existing process.
+
+ foreach my $host (keys %hosts) {
+ if(!(exists $HostHash{$host})) {
+ Log("INFO", "New host $host discovered in hosts.tab...");
+ $HostHash{$host} = $hosts{$host};
+ CreateChild($host);
+ } else {
+ kill 'HUP' => $HostToPid{$host}; # status display.
+ }
+ }
+}
+
+
+=pod
+
+=head1 Restart
+
+Signal handler for HUP... all children are killed and
+we self restart. This is an el-cheapo way to re read
+the config file.
+
+=cut
+
+sub Restart {
+ &KillThemAll; # First kill all the children.
+ Log("CRITICAL", "Restarting");
+ my $execdir = $perlvar{'lonDaemons'};
+ unlink("$execdir/logs/lonc.pid");
+ exec("$execdir/loncnew");
+}
+
+=pod
+
+=head1 KillThemAll
+
+Signal handler that kills all children by sending them a
+SIGHUP. Responds to sigint and sigterm.
+
+=cut
+
+sub KillThemAll {
+ Debug(2, "Kill them all!!");
+ local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
+ foreach my $pid (keys %ChildHash) {
+ my $serving = $ChildHash{$pid};
+ Debug(2, "Killing lonc for $serving pid = $pid");
+ ShowStatus("Killing lonc for $serving pid = $pid");
+ Log("CRITICAL", "Killing lonc for $serving pid = $pid");
+ kill 'QUIT' => $pid;
+ delete($ChildHash{$pid});
+ }
+ my $execdir = $perlvar{'lonDaemons'};
+ unlink("$execdir/logs/lonc.pid");
+
+}
+
+=pod
+
+=head1 Terminate
+
+Terminate the system.
+
+=cut
+
+sub Terminate {
+ KillThemAll;
+ Log("CRITICAL","Master process exiting");
+ exit 0;
+
+}
+=pod
+
=head1 Theory
The event class is used to build this as a single process with an
500 Internal Server Error
Internal Server Error
The server encountered an internal error or
misconfiguration and was unable to complete
your request.
Please contact the server administrator at
root@localhost to inform them of the time this error occurred,
and the actions you performed just before this error.
More information about this error may be available
in the server error log.