--- loncom/loncron	2010/08/17 22:22:00	1.86
+++ loncom/loncron	2011/10/28 18:38:00	1.92
@@ -2,7 +2,7 @@
 
 # Housekeeping program, started by cron, loncontrol and loncron.pl
 #
-# $Id: loncron,v 1.86 2010/08/17 22:22:00 raeburn Exp $
+# $Id: loncron,v 1.92 2011/10/28 18:38:00 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -32,6 +32,7 @@ use strict;
 
 use lib '/home/httpd/lib/perl/';
 use LONCAPA::Configuration;
+use LONCAPA;
 use Apache::lonnet;
 use Apache::loncommon;
 
@@ -651,8 +652,18 @@ sub check_delayed_msg {
 # pong to all servers that have delayed messages
 # this will trigger a reverse connection, which should flush the buffers
     foreach my $tryserver (keys %servers) {
-	my $answer=&Apache::lonnet::reply("pong",$tryserver);
-	&log($fh,"Pong to $tryserver: $answer<br />");
+        my $answer;
+        eval {
+            local $SIG{ ALRM } = sub { die "TIMEOUT" };
+            alarm(20);
+            $answer = &Apache::lonnet::reply("pong",$tryserver);
+            alarm(0);
+        };
+        if ($@ && $@ =~ m/TIMEOUT/) {
+            print "time out while contacting: $tryserver for pong\n";
+        } else {
+            &log($fh,"Pong to $tryserver: $answer<br />");
+        }
     }
 }
 
@@ -686,11 +697,22 @@ sub log_simplestatus {
 }
 
 sub write_loncaparevs {
+    print "Retrieving LON-CAPA version information\n";
     if (open(my $fh,">$perlvar{'lonTabDir'}/loncaparevs.tab")) {
         my %hostname = &Apache::lonnet::all_hostnames();
         foreach my $id (sort(keys(%hostname))) {
             if ($id ne '') {
-                my $loncaparev = &Apache::lonnet::get_server_loncaparev('',$id,1,'loncron');
+                my $loncaparev;
+                eval {
+                    local $SIG{ ALRM } = sub { die "TIMEOUT" };
+                    alarm(10);
+                    $loncaparev =
+                        &Apache::lonnet::get_server_loncaparev('',$id,1,'loncron');
+                    alarm(0);
+                };
+                if ($@ && $@ =~ m/TIMEOUT/) {
+                    print "time out while contacting lonHost: $id for version\n";   
+                }
                 if ($loncaparev =~ /^[\w.\-]+$/) {
                     print $fh $id.':'.$loncaparev."\n";
                 }
@@ -702,12 +724,23 @@ sub write_loncaparevs {
 }
 
 sub write_serverhomeIDs {
+    print "Retrieving LON-CAPA lonHostID information\n";
     if (open(my $fh,">$perlvar{'lonTabDir'}/serverhomeIDs.tab")) {
         my %name_to_host = &Apache::lonnet::all_names();
         foreach my $name (sort(keys(%name_to_host))) {
             if ($name ne '') {
                 if (ref($name_to_host{$name}) eq 'ARRAY') {
-                    my $serverhomeID = &Apache::lonnet::get_server_homeID($name,1,'loncron');
+                    my $serverhomeID;
+                    eval {
+                        local $SIG{ ALRM } = sub { die "TIMEOUT" };
+                        alarm(10);
+                        $serverhomeID = 
+                            &Apache::lonnet::get_server_homeID($name,1,'loncron');
+                        alarm(0);
+                    };
+                    if ($@ && $@ =~ m/TIMEOUT/) {
+                        print "Time out while contacting server: $name\n"; 
+                    }
                     if ($serverhomeID ne '') {
                         print $fh $name.':'.$serverhomeID."\n";
                     } else {
@@ -821,9 +854,12 @@ sub main () {
                 print $fh "$key\n";
             }
             close($fh);
-            my $execpath = $perlvar{'lonDaemons'}.'/lciptables';
-            system("$execpath $tmpfile");
-            unlink($fh);
+            if (&LONCAPA::try_to_lock('/tmp/lock_lciptables')) {
+                my $execpath = $perlvar{'lonDaemons'}.'/lciptables';
+                system("$execpath $tmpfile");
+                unlink('/tmp/lock_lciptables');  # Remove the lock file. 
+            }
+            unlink($tmpfile);
         }
     }
 
@@ -866,12 +902,10 @@ sub main () {
 	&check_delayed_msg($fh);
 	&finish_logging($fh);
 	&log_simplestatus();
-	
-	if ($totalcount>200 && !$noemail) { &send_mail(); }
-    }
-    if (!$justcheckconnections && !$justreload) {
         &write_loncaparevs();
         &write_serverhomeIDs();
+	
+	if ($totalcount>200 && !$noemail) { &send_mail(); }
     }
 }