--- loncom/lonnet/perl/lonnet.pm	2006/09/19 21:36:41	1.783
+++ loncom/lonnet/perl/lonnet.pm	2006/10/04 21:02:41	1.789
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.783 2006/09/19 21:36:41 albertel Exp $
+# $Id: lonnet.pm,v 1.789 2006/10/04 21:02:41 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -303,6 +303,9 @@ sub convert_and_load_session_env {
     }
     my %temp_env;
     foreach my $line (@profile) {
+	if ($line !~ m/=/) {
+	    return 0;
+	}
 	chomp($line);
 	my ($envname,$envvalue)=split(/=/,$line,2);
 	$temp_env{&unescape($envname)} = &unescape($envvalue);
@@ -314,14 +317,15 @@ sub convert_and_load_session_env {
 	@env{keys(%temp_env)} = @disk_env{keys(%temp_env)};
 	untie(%disk_env);
     }
+    return 1;
 }
 
 # ------------------------------------------- Transfer profile into environment
 my $env_loaded;
 sub transfer_profile_to_env {
-    if ($env_loaded) { return; } 
+    my ($lonidsdir,$handle,$force_transfer) = @_;
+    if (!$force_transfer && $env_loaded) { return; } 
 
-    my ($lonidsdir,$handle)=@_;
     if (!defined($lonidsdir)) {
 	$lonidsdir = $perlvar{'lonIDsDir'};
     }
@@ -329,15 +333,25 @@ sub transfer_profile_to_env {
         ($handle) = ($env{'user.environment'} =~m|/([^/]+)\.id$| );
     }
 
-    my %remove;
-    if (tie(my %disk_env,'GDBM_File',"$lonidsdir/$handle.id",&GDBM_READER(),
-	    0640)) {
-	@env{keys(%disk_env)} = @disk_env{keys(%disk_env)};
-	untie(%disk_env);
-    } else {
-	&convert_and_load_session_env($lonidsdir,$handle);
+    my $convert;
+    {
+    	open(my $idf,"$lonidsdir/$handle.id");
+	flock($idf,LOCK_SH);
+	if (tie(my %disk_env,'GDBM_File',"$lonidsdir/$handle.id",
+		&GDBM_READER(),0640)) {
+	    @env{keys(%disk_env)} = @disk_env{keys(%disk_env)};
+	    untie(%disk_env);
+	} else {
+	    $convert = 1;
+	}
+    }
+    if ($convert) {
+	if (!&convert_and_load_session_env($lonidsdir,$handle)) {
+	    &logthis("Failed to load session, or convert session.");
+	}
     }
 
+    my %remove;
     while ( my $envname = each(%env) ) {
         if (my ($key,$time) = ($envname =~ /^(cgi\.(\d+)_\d+\.)/)) {
             if ($time < time-300) {
@@ -450,41 +464,60 @@ sub overloaderror {
 
 sub spareserver {
     my ($loadpercent,$userloadpercent,$want_server_name) = @_;
-    my $tryserver;
-    my $spareserver='';
+    my $spare_server;
     if ($userloadpercent !~ /\d/) { $userloadpercent=0; }
-    my $lowestserver=$loadpercent > $userloadpercent?
-	             $loadpercent :  $userloadpercent;
-    foreach $tryserver (keys(%spareid)) {
-	my $loadans=&reply('load',$tryserver);
-	my $userloadans=&reply('userload',$tryserver);
-	if ($loadans !~ /\d/ && $userloadans !~ /\d/) {
-	    next; #didn't get a number from the server
-	}
-	my $answer;
-	if ($loadans =~ /\d/) {
-	    if ($userloadans =~ /\d/) {
-		#both are numbers, pick the bigger one
-		$answer=$loadans > $userloadans?
-		    $loadans :  $userloadans;
-	    } else {
-		$answer = $loadans;
-	    }
-	} else {
-	    $answer = $userloadans;
-	}
-	if (($answer =~ /\d/) && ($answer<$lowestserver)) {
-	    if ($want_server_name) {
-		$spareserver=$tryserver;
-	    } else {
-		$spareserver="http://$hostname{$tryserver}";
-	    }
-	    $lowestserver=$answer;
+    my $lowest_load=($loadpercent > $userloadpercent) ? $loadpercent 
+                                                     :  $userloadpercent;
+    
+    foreach my $try_server (@{ $spareid{'primary'} }) {
+	($spare_server, $lowest_load) =
+	    &compare_server_load($try_server, $spare_server, $lowest_load);
+    }
+
+    my $found_server = ($spare_server ne '' && $lowest_load < 100);
+
+    if (!$found_server) {
+	foreach my $try_server (@{ $spareid{'default'} }) {
+	    ($spare_server, $lowest_load) =
+		&compare_server_load($try_server, $spare_server, $lowest_load);
 	}
     }
-    return $spareserver;
+
+    if (!$want_server_name) {
+	$spare_server="http://$hostname{$spare_server}";
+    }
+    return $spare_server;
 }
 
+sub compare_server_load {
+    my ($try_server, $spare_server, $lowest_load) = @_;
+
+    my $loadans     = &reply('load',    $try_server);
+    my $userloadans = &reply('userload',$try_server);
+
+    if ($loadans !~ /\d/ && $userloadans !~ /\d/) {
+	next; #didn't get a number from the server
+    }
+
+    my $load;
+    if ($loadans =~ /\d/) {
+	if ($userloadans =~ /\d/) {
+	    #both are numbers, pick the bigger one
+	    $load = ($loadans > $userloadans) ? $loadans 
+		                              : $userloadans;
+	} else {
+	    $load = $loadans;
+	}
+    } else {
+	$load = $userloadans;
+    }
+
+    if (($load =~ /\d/) && ($load < $lowest_load)) {
+	$spare_server = $try_server;
+	$lowest_load  = $load;
+    }
+    return ($spare_server,$lowest_load);
+}
 # --------------------------------------------- Try to change a user's password
 
 sub changepass {
@@ -1151,15 +1184,6 @@ sub absolute_url {
     return $protocol.$host_name;
 }
 
-sub absolute_url {
-    my ($host_name) = @_;
-    my $protocol = ($ENV{'SERVER_PORT'} == 443?'https://':'http://');
-    if ($host_name eq '') {
-	$host_name = $ENV{'SERVER_NAME'};
-    }
-    return $protocol.$host_name;
-}
-
 sub ssi {
 
     my ($fn,%form)=@_;
@@ -5253,13 +5277,8 @@ sub GetFileTimestamp {
 
 sub stat_file {
     my ($uri) = @_;
-    $uri = &clutter($uri);
+    $uri = &clutter_with_no_wrapper($uri);
 
-    # we want just the url part without the unneeded accessor url bits
-    if ($uri =~ m-^/adm/-) {
-	$uri=~s-^/adm/wrapper/-/-;
-	$uri=~s-^/adm/coursedocs/showdoc/-/-;
-    }
     my ($udom,$uname,$file,$dir);
     if ($uri =~ m-^/(uploaded|editupload)/-) {
 	($udom,$uname,$file) =
@@ -6195,9 +6214,6 @@ sub symblist {
 sub symbverify {
     my ($symb,$thisurl)=@_;
     my $thisfn=$thisurl;
-# wrapper not part of symbs
-    $thisfn=~s/^\/adm\/wrapper//;
-    $thisfn=~s/^\/adm\/coursedocs\/showdoc\///;
     $thisfn=&declutter($thisfn);
 # direct jump to resource in page or to a sequence - will construct own symbs
     if ($thisfn=~/\.(page|sequence)$/) { return 1; }
@@ -7034,6 +7050,15 @@ sub clutter {
     return $thisfn;
 }
 
+sub clutter_with_no_wrapper {
+    my $uri = &clutter(shift);
+    if ($uri =~ m-^/adm/-) {
+	$uri =~ s-^/adm/wrapper/-/-;
+	$uri =~ s-^/adm/coursedocs/showdoc/-/-;
+    }
+    return $uri;
+}
+
 sub freeze_escape {
     my ($value)=@_;
     if (ref($value)) {
@@ -7169,7 +7194,9 @@ sub get_iphost {
     while (my $configline=<$config>) {
        chomp($configline);
        if ($configline) {
-          $spareid{$configline}=1;
+	   my ($host,$type) = split(':',$configline,2);
+	   if (!defined($type) || $type eq '') { $type = 'default' };
+	   push(@{ $spareid{$type} }, $host);
        }
     }
     close($config);