--- loncom/loncnew	2003/09/15 09:24:49	1.23
+++ loncom/loncnew	2004/07/02 09:28:14	1.50
@@ -2,7 +2,7 @@
 # The LearningOnline Network with CAPA
 # lonc maintains the connections to remote computers
 #
-# $Id: loncnew,v 1.23 2003/09/15 09:24:49 foxr Exp $
+# $Id: loncnew,v 1.50 2004/07/02 09:28:14 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -35,91 +35,16 @@
 #    - Add ability to create/negotiate lond connections (done).
 #    - Add general logic for dispatching requests and timeouts. (done).
 #    - Add support for the lonc/lond requests.          (done).
-#    - Add logging/status monitoring.
-#    - Add Signal handling - HUP restarts. USR1 status report.
+#    - 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.
+#    - Add management/status request interface.         (done)
 #    - Add deferred request capability.                  (done)
-#    - Detect transmission timeouts.
+#    - Detect transmission timeouts.                     (done)
 #
 
-# Change log:
-#    $Log: loncnew,v $
-#    Revision 1.23  2003/09/15 09:24:49  foxr
-#    Add use strict and fix all the fallout from that.
-#
-#    Revision 1.22  2003/09/02 10:34:47  foxr
-#    - Fix errors in host dead detection logic (too many cases where the
-#      retries left were not getting incremented or just not checked).
-#    - Added some additional status to the ps axuww display:
-#      o Remaining retries on a host.
-#      o >>> DEAD <<< indicator if I've given up on a host.
-#    - Tested the SIGHUP will reset the retries remaining count (thanks to
-#      the above status stuff, and get allow the loncnew to re-try again
-#      on the host (thanks to the log).
-#
-#    Revision 1.21  2003/08/26 09:19:51  foxr
-#    How embarrassing... put in the SocketTimeout function in loncnew and forgot
-#    to actually hook it into the LondTransaction.  Added this to MakeLondConnection
-#    where it belongs... hopefully transactions (not just connection attempts) will
-#    timeout more speedily than the socket errors will catch it.
-#
-#    Revision 1.20  2003/08/25 18:48:11  albertel
-#    - fixing a forgotten ;
-#
-#    Revision 1.19  2003/08/19 09:31:46  foxr
-#    Get socket directory from configuration rather than the old hard coded test
-#    way that I forgot to un-hard code.
-#
-#    Revision 1.18  2003/08/06 09:52:29  foxr
-#    Also needed to remember to fail in-flight transactions if their sends fail.
-#
-#    Revision 1.17  2003/08/03 00:44:31  foxr
-#    1. Correct handling of connection failure: Assume it means the host is
-#       unreachable and fail all of the queued transactions.  Note that the
-#       inflight transactions should fail on their own time due either to timeout
-#       or send/receive failures.
-#    2. Correct handling of logs for forced death signals.  Pull the signal
-#       from the event watcher.
-#
-#    Revision 1.16  2003/07/29 02:33:05  foxr
-#    Add SIGINT processing to child processes to toggle annoying trace mode
-#    on/off.. will try to use this to isolate the compute boud process issue.
-#
-#    Revision 1.15  2003/07/15 02:07:05  foxr
-#    Added code for lonc/lond transaction timeouts.  Who knows if it works right.
-#    The intent is for a timeout to fail any transaction in progress and kill
-#    off the sockt that timed out.
-#
-#    Revision 1.14  2003/07/03 02:10:18  foxr
-#    Get all of the signals to work correctly.
-#
-#    Revision 1.13  2003/07/02 01:31:55  foxr
-#    Added kill -HUP logic (restart).
-#
-#    Revision 1.11  2003/06/25 01:54:44  foxr
-#    Fix more problems with transaction failure.
-#
-#    Revision 1.10  2003/06/24 02:46:04  foxr
-#    Put a limit on  the number of times we'll retry a connection.
-#    Start getting the signal stuff put in as well...note that need to get signals
-#    going or else the client will permanently give up on dead servers.
-#
-#    Revision 1.9  2003/06/13 02:38:43  foxr
-#    Add logging in 'expected format'
-#
-#    Revision 1.8  2003/06/11 02:04:35  foxr
-#    Support delayed transactions... this is done uniformly by encapsulating
-#    transactions in an object ... a LondTransaction that is implemented by
-#    LondTransaction.pm
-#
-#    Revision 1.7  2003/06/03 01:59:39  foxr
-#    complete coding to support deferred transactions.
-#
-#
 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;
@@ -138,17 +63,6 @@ use LONCAPA::Configuration;
 use LONCAPA::HashIterator;
 
 
-#
-#   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:
 
@@ -159,14 +73,18 @@ my %perlvar    = %{$perlvarref};
 #  parent and shared variables.
 
 my %ChildHash;			# by pid -> host.
+my %HostToPid;			# By host -> pid.
+my %HostHash;			# by loncapaname -> IP.
 
 
 my $MaxConnectionCount = 10;	# Will get from config later.
 my $ClientConnection = 0;	# Uniquifier for client events.
 
 my $DebugLevel = 0;
-my $NextDebugLevel= 10;		# So Sigint can toggle this.
-my $IdleTimeout= 3600;		# Wait an hour before pruning connections.
+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.
@@ -182,8 +100,10 @@ my $ConnectionCount = 0;
 my $IdleSeconds     = 0;	# Number of seconds idle.
 my $Status          = "";	# Current status string.
 my $RecentLogEntry  = "";
-my $ConnectionRetries=5;	# Number of connection retries allowed.
-my $ConnectionRetriesLeft=5;	# Number of connection retries remaining.
+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.
 
 #
 #   The hash below gives the HTML format for log messages
@@ -191,10 +111,10 @@ my $ConnectionRetriesLeft=5;	# Number of
 #    
 my %LogFormats;
 
-$LogFormats{"CRITICAL"} = "<font color=red>CRITICAL: %s</font>";
-$LogFormats{"SUCCESS"}  = "<font color=green>SUCCESS: %s</font>";
-$LogFormats{"INFO"}     = "<font color=yellow>INFO: %s</font>";
-$LogFormats{"WARNING"}  = "<font color=blue>WARNING: %s</font>";
+$LogFormats{"CRITICAL"} = "<font color='red'>CRITICAL: %s</font>";
+$LogFormats{"SUCCESS"}  = "<font color='green'>SUCCESS: %s</font>";
+$LogFormats{"INFO"}     = "<font color='yellow'>INFO: %s</font>";
+$LogFormats{"WARNING"}  = "<font color='blue'>WARNING: %s</font>";
 $LogFormats{"DEFAULT"}  = " %s ";
 
 
@@ -237,9 +157,9 @@ host and the time will be formatted into
 =cut
 
 sub Log {
-    my $severity = shift;
-    my $message  = shift;
-   
+
+    my ($severity, $message) = @_;
+
     if(!$LogFormats{$severity}) {
 	$severity = "DEFAULT";
     }
@@ -274,8 +194,10 @@ 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;
@@ -289,7 +211,6 @@ sub GetPeername {
 	return $peerfile;
     }
 }
-#----------------------------- Timer management ------------------------
 =pod
 
 =head2 Debug
@@ -299,18 +220,20 @@ Invoked to issue a debug message.
 =cut
 
 sub Debug {
-    my $level   = shift;
-    my $message = shift;
+
+    my ($level, $message) = @_;
+
     if ($level <= $DebugLevel) {
 	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.
     }
 }
 
@@ -341,11 +264,21 @@ sub ShowStatus {
 =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
 
@@ -360,7 +293,8 @@ sub Tick {
     my $client;
     if($ConnectionRetriesLeft > 0) {
 	ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
-		   ." Retries remaining: ".$ConnectionRetriesLeft);
+		   ." Retries remaining: ".$ConnectionRetriesLeft
+		   ." ($KeyMode)");
     } else {
 	ShowStatus(GetServerHost()." >> DEAD <<");
     }
@@ -380,9 +314,13 @@ sub Tick {
     #
     #  For each inflight transaction, tick down its timeout counter.
     #
-    foreach my $item (keys %ActiveTransactions) {
-	my $Socket = $ActiveTransactions{$item}->getServer();
-	$Socket->Tick();
+
+    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.
@@ -393,22 +331,27 @@ sub Tick {
 	if ($ConnectionRetriesLeft > 0) {
 	    my $Connections = ($Requests <= $MaxConnectionCount) ?
 		$Requests : $MaxConnectionCount;
-	    Debug(1,"Work but no connections, start ".$Connections." of them");
+	    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(1,"Work in queue failed to make any connectiouns\n");
+		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(1,"Work in queue, but gave up on connections..flushing\n");
+	    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
@@ -429,7 +372,7 @@ Trigger disconnections of idle sockets.
 
 sub SetupTimer {
     Debug(6, "SetupTimer");
-    Event->timer(interval => 1, debug => 1, cb => \&Tick );
+    Event->timer(interval => 1, cb => \&Tick );
 }
 
 =pod
@@ -449,21 +392,22 @@ 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:
 
     my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
-    unless($reqdata eq undef)  {
-	Debug(9, "Queue gave request data: ".$reqdata->getRequest());
+    if ($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");
+	&Debug(5, "No new work requests, server connection going idle");
 	$IdleConnections->push($Socket);
     }
 }
@@ -509,7 +453,7 @@ sub ClientWritable {
 	# request.
 	
 	&Debug(9,"Send result is ".$result." Defined: ".defined($result));
-	if(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");
@@ -580,12 +524,15 @@ The transaction that is being completed.
 =cut
 
 sub CompleteTransaction {
-    &Debug(6,"Complete transaction");
-    my $Socket = shift;
-    my $Transaction = shift;
+    &Debug(5,"Complete transaction");
+
+    my ($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");
@@ -593,7 +540,9 @@ sub CompleteTransaction {
 	unlink $Transaction->getFile();
     }
 }
+
 =pod
+
 =head1 StartClientReply
 
    Initiates a reply to a client where the reply data is a parameter.
@@ -609,17 +558,16 @@ sub CompleteTransaction {
     The data to send to apached client.
 
 =cut
+
 sub StartClientReply {
-    my $Transaction   = shift;
-    my $data     = shift;
 
+    my ($Transaction, $data) = @_;
 
     my $Client   = $Transaction->getClient();
 
     &Debug(8," Reply was: ".$data);
     my $Serial         = $ActiveClients{$Client};
     my $desc           = sprintf("Connection to lonc client %d",
-
 				 $Serial);
     Event->io(fd       => $Client,
 	      poll     => "w",
@@ -627,7 +575,9 @@ sub StartClientReply {
 	      cb       => \&ClientWritable,
 	      data     => $data);
 }
+
 =pod
+
 =head2 FailTransaction
 
   Finishes a transaction with failure because the associated lond socket
@@ -637,8 +587,7 @@ sub StartClientReply {
   - 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.
+Deleting the transaction means killing it from the %ActiveTransactions hash.
 
 Parameters:
 
@@ -646,6 +595,7 @@ Parameters:
  
    The LondTransaction we are failing.
  
+
 =cut
 
 sub FailTransaction {
@@ -657,9 +607,6 @@ sub FailTransaction {
 	Debug(1," Replying con_lost to ".$transaction->getRequest());
 	StartClientReply($transaction, "con_lost\n");
     }
-    if($ConnectionRetriesLeft <= 0) {
-	Log("CRITICAL", "Host marked dead: ".GetServerHost());
-    }
 
 }
 
@@ -687,7 +634,10 @@ Close all connections open on lond prior
 =cut
 sub CloseAllLondConnections {
     foreach my $Socket (keys %ActiveConnections) {
-	KillSocket($Socket);
+      if(exists($ActiveTransactions{$Socket})) {
+	FailTransaction($ActiveTransactions{$Socket});
+      }
+      KillSocket($Socket);
     }
 }
 =cut
@@ -731,14 +681,15 @@ sub KillSocket {
     }
     if(exists($ActiveConnections{$Socket})) {
 	delete($ActiveConnections{$Socket});
+	$ConnectionCount--;
+	if ($ConnectionCount < 0) { $ConnectionCount = 0; }
     }
-    $ConnectionCount--;
-
     #  If the connection count has gone to zero and there is work in the
     #  work queue, the work all gets failed with con_lost.
     #
     if($ConnectionCount == 0) {
 	EmptyQueue();
+	CloseAllLondConnections; # Should all already be closed but...
     }
 }
 
@@ -764,6 +715,17 @@ 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
@@ -818,7 +780,7 @@ sub LondReadable {
     &Debug(2, "Socket->Readable returned: $status");
 
     if($status != 0) {
-	 # bad return from socket read. Currently this means that
+	# bad return from socket read. Currently this means that
 	# The socket has become disconnected. We fail the transaction.
 
 	Log("WARNING",
@@ -836,19 +798,34 @@ 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->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 ($State eq "RequestingKey") {
 	#  The ok was received.  Now we need to request the key
@@ -860,6 +837,14 @@ sub LondReadable {
     } elsif ($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
@@ -868,7 +853,7 @@ sub LondReadable {
 	$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 {
@@ -889,7 +874,7 @@ sub LondReadable {
 
 
     } else {
-	 # Invalid state.
+	# Invalid state.
 	Debug(4, "Invalid state in LondReadable");
     }
 }
@@ -971,21 +956,36 @@ sub LondWritable {
 
     SocketDump(6,$Socket);
 
-    if      ($State eq "Connected")         {
-
-	if ($Socket->Writable() != 0) {
-	    #  The write resulted in an error.
-	    # We'll treat this as if the socket got disconnected:
-	    Log("WARNING", "Connection to ".$RemoteHost.
-		" has been disconnected");
+    #  If the socket is writable, we must always write.
+    # Only by writing will we undergo state transitions.
+    # Old logic wrote in state specific code below, however
+    # That forces us at least through another invocation of
+    # this function after writability is possible again.
+    # This logic also factors out common code for handling
+    # write failures... in all cases, write failures 
+    # Kill the socket.
+    #  This logic makes the branches of the >big< if below
+    # so that the writing states are actually NO-OPs.
+
+    if ($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;
 	}
-	#  "init" is being sent...
+	$Watcher->cancel();
+	KillSocket($Socket);
+	return;
+    }
 
-	
+
+
+    if      ($State eq "Connected")         {
+
+	#  "init" is being sent...
+ 
     } elsif ($State eq "Initialized")       {
 
 	# Now that init was sent, we switch 
@@ -993,40 +993,43 @@ sub LondWritable {
 
 	$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);
-	    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);
-	    return;
-
-	}
     } elsif ($State eq "ReceivingKey")      {
 	# Now we need to wait for the key
 	# to come back from the peer:
@@ -1035,20 +1038,10 @@ sub LondWritable {
 	$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);
-	    return;
-	    
-	}
 
     } elsif ($State eq "ReceivingReply")    {
 	# The send has completed.  Wait for the
@@ -1115,7 +1108,7 @@ sub MakeLondConnection {
     my $Connection = LondConnection->new(&GetServerHost(),
 					 &GetServerPort());
 
-    if($Connection == undef) {	# Needs to be more robust later.
+    if($Connection eq undef) {	# Needs to be more robust later.
 	Log("CRITICAL","Failed to make a connection with lond.");
 	$ConnectionRetriesLeft--;
 	return 0;		# Failure.
@@ -1127,7 +1120,7 @@ sub MakeLondConnection {
 	# 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);
@@ -1180,8 +1173,8 @@ The text of the request to send.
 =cut
 
 sub StartRequest {
-    my $Lond     = shift;
-    my $Request  = shift;	# This is a LondTransaction.
+
+    my ($Lond, $Request) = @_;
     
     Debug(6, "StartRequest: ".$Request->getRequest());
 
@@ -1230,17 +1223,19 @@ sub QueueTransaction {
 
     my $LondSocket    = $IdleConnections->pop();
     if(!defined $LondSocket) {	# Need to queue request.
-	Debug(8,"Must queue...");
+	Debug(5,"Must queue...");
 	$WorkQueue->enqueue($requestData);
 	if($ConnectionCount < $MaxConnectionCount) {
 	    if($ConnectionRetriesLeft > 0) {
-		Debug(4,"Starting additional lond connection");
+		Debug(5,"Starting additional lond connection");
 		if(MakeLondConnection() == 0) {
 		    EmptyQueue();	# Fail transactions, can't make connection.
+		    CloseAllLondConnections; # Should all be closed but...
 		}
 	    } 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:
@@ -1272,7 +1267,7 @@ 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);
@@ -1283,7 +1278,7 @@ sub ClientRequest {
     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");
@@ -1291,6 +1286,9 @@ sub ClientRequest {
 	    exit;
 	}
 	Debug(8, "Complete transaction received: ".$data);
+	if($LogTransactions) {
+	    Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
+	}
 	my $Transaction = LondTransaction->new($data);
 	$Transaction->SetClient($socket);
 	QueueTransaction($Transaction);
@@ -1399,6 +1397,24 @@ 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
@@ -1409,6 +1425,7 @@ 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;
@@ -1418,6 +1435,22 @@ sub ChildStatus {
     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;
 }
 
@@ -1482,6 +1515,8 @@ sub ChildProcess {
     Event->signal(signal   => "USR1",
 		  cb       => \&ChildStatus,
 		  data     => "USR1");
+    Event->signal(signal   => "USR2",
+		  cb       => \&ToggleTransactionLogging);
     Event->signal(signal   => "INT",
 		  cb       => \&ToggleDebug,
 		  data     => "INT");
@@ -1517,7 +1552,8 @@ sub CreateChild {
     my $pid          = fork;
     if($pid) {			# Parent
 	$RemoteHost = "Parent";
-	$ChildHash{$pid} = $RemoteHost;
+	$ChildHash{$pid} = $host;
+	$HostToPid{$host}= $pid;
 	sigprocmask(SIG_UNBLOCK, $sigset);
 
     } else {			# child.
@@ -1575,11 +1611,13 @@ ShowStatus("Forking node servers");
 
 Log("CRITICAL", "--------------- Starting children ---------------");
 
+LondConnection::ReadConfig;               # Read standard config files.
 my $HostIterator = LondConnection::GetHostIterator;
 while (! $HostIterator->end()) {
 
     my $hostentryref = $HostIterator->get();
     CreateChild($hostentryref->[0]);
+    $HostHash{$hostentryref->[0]} = $hostentryref->[4];
     $HostIterator->next();
 }
 $RemoteHost = "Parent Server";
@@ -1596,11 +1634,13 @@ $SIG{INT}  = \&Terminate;
 $SIG{TERM} = \&Terminate; 
 $SIG{HUP}  = \&Restart;
 $SIG{USR1} = \&CheckKids; 
+$SIG{USR2} = \&UpdateKids;	# LonManage update request.
 
 while(1) {
     my $deadchild = wait();
     if(exists $ChildHash{$deadchild}) {	# need to restart.
 	my $deadhost = $ChildHash{$deadchild};
+	delete($HostToPid{$deadhost});
 	delete($ChildHash{$deadchild});
 	Log("WARNING","Lost child pid= ".$deadchild.
 	      "Connected to host ".$deadhost);
@@ -1639,6 +1679,114 @@ sub CheckKids {
 
 =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
@@ -1652,7 +1800,7 @@ sub Restart {
     Log("CRITICAL", "Restarting");
     my $execdir = $perlvar{'lonDaemons'};
     unlink("$execdir/logs/lonc.pid");
-    exec("$execdir/lonc");
+    exec("$execdir/loncnew");
 }
 
 =pod