--- loncom/lonnet/perl/lonnet.pm	2002/09/16 13:04:16	1.281
+++ loncom/lonnet/perl/lonnet.pm	2002/09/17 21:19:19	1.285
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.281 2002/09/16 13:04:16 www Exp $
+# $Id: lonnet.pm,v 1.285 2002/09/17 21:19:19 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -348,12 +348,36 @@ sub delenv {
     return 'ok';
 }
 
+# ------------------------------------------ Fight off request when overloaded
+
+sub overloaderror {
+    my ($r,$checkserver)=@_;
+    unless ($checkserver) { $checkserver=$perlvar{'lonHostID'}; }
+    my $loadavg;
+    if ($checkserver eq $perlvar{'lonHostID'}) {
+       my $loadfile=Apache::File->new('/proc/loadavg');
+       $loadavg=<$loadfile>;
+       $loadavg =~ s/\s.*//g;
+       $loadavg = 100*$loadavg/$perlvar{'lonLoadLim'};
+    } else {
+       $loadavg=&reply('load',$checkserver);
+    }
+    my $overload=$loadavg-100;
+    if ($overload>0) {
+	$r->err_headers_out->{'Retry-After'}=$overload;
+        $r->log_error('Overload of '.$overload.' on '.$checkserver);
+        return 413;
+    }    
+    return '';
+}
+
 # ------------------------------ Find server with least workload from spare.tab
 
 sub spareserver {
+    my $loadpercent = shift;
     my $tryserver;
     my $spareserver='';
-    my $lowestserver=100;
+    my $lowestserver=$loadpercent; 
     foreach $tryserver (keys %spareid) {
        my $answer=reply('load',$tryserver);
        if (($answer =~ /\d/) && ($answer<$lowestserver)) {
@@ -2574,7 +2598,7 @@ sub courseresdata {
 # --------------------------------------------------------- Value of a Variable
 
 sub EXT {
-    my ($varname,$symbparm,$udom,$uname)=@_;
+    my ($varname,$symbparm,$udom,$uname,)=@_;
 
     unless ($varname) { return ''; }
 
@@ -2731,10 +2755,16 @@ sub EXT {
 # --------------------------------------------- last, look in resource metadata
 
 	$spacequalifierrest=~s/\./\_/;
-	my $metadata=&metadata($ENV{'request.filename'},$spacequalifierrest);
+	my $filename;
+	if (!$symbparm) { $symbparm=&symbread(); }
+	if ($symbparm) {
+	    $filename=(split(/\_\_\_/,$symbparm))[2];
+	} else {
+	    $filename=$ENV{'request.filename'};
+	}
+	my $metadata=&metadata($filename,$spacequalifierrest);
 	if ($metadata) { return $metadata; }
-	$metadata=&metadata($ENV{'request.filename'},
-			    'parameter_'.$spacequalifierrest);
+	$metadata=&metadata($filename,'parameter_'.$spacequalifierrest);
 	if ($metadata) { return $metadata; }
 
 # ------------------------------------------------------------------ Cascade up
@@ -3301,7 +3331,7 @@ BEGIN {
 
     while (my $configline=<$config>) {
        chomp($configline);
-       if (($configline) && ($configline ne $perlvar{'lonHostID'})) {
+       if ($configline) {
           $spareid{$configline}=1;
        }
     }