--- loncom/auth/lonauth.pm	2010/07/17 20:02:02	1.105
+++ loncom/auth/lonauth.pm	2010/09/23 23:47:33	1.110
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # User Authentication Module
 #
-# $Id: lonauth.pm,v 1.105 2010/07/17 20:02:02 raeburn Exp $
+# $Id: lonauth.pm,v 1.110 2010/09/23 23:47:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -40,6 +40,7 @@ use Apache::lonmenu();
 use Apache::createaccount;
 use Fcntl qw(:flock);
 use Apache::lonlocal;
+use Apache::File ();
 use HTML::Entities;
  
 # ------------------------------------------------------------ Successful login
@@ -351,7 +352,9 @@ sub handler {
             &Apache::lonnet::get_dom('configuration',['usercreation'],$form{'udom'});
         if (grep(/^login$/,@cancreate)) {
             my $domdesc = &Apache::lonnet::domain($form{'udom'},'description');
-            &check_can_host($r,\%form,'no_account_on_host',$domdesc);
+            unless (&check_can_host($r,\%form,'no_account_on_host',$domdesc)) {
+                return OK;
+            }
             my $start_page = 
                 &Apache::loncommon::start_page('Create a user account in LON-CAPA');
             my $lonhost = $r->dir_config('lonHostID');
@@ -403,41 +406,79 @@ sub handler {
 	}
     }
 
-    &check_can_host($r,\%form,$authhost);
+    unless (&check_can_host($r,\%form,$authhost)) {
+        return OK;
+    }
 
     if ($r->dir_config("lonBalancer") eq 'yes') {
 	&success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',undef,
 		 \%form);
-        my ($otherserver) = &choose_server($form{'udom'});
-	$r->internal_redirect('/adm/switchserver?otherserver='.$otherserver);
+        my ($otherserver) = &Apache::lonnet::choose_server($form{'udom'});
+	$r->internal_redirect('/adm/switchserver?otherserver='.$otherserver.'&origurl='.$firsturl);
+        return OK;
     } else {
-	&success($r,$form{'uname'},$form{'udom'},$authhost,$firsturl,undef,
-		 \%form);
+# ------------------------------------------------------- Do the load balancing
+
+# ---------------------------------------------------------- Determine own load
+        my $loadlim = $r->dir_config('lonLoadLim');
+        my $loadavg;
+        {
+            my $loadfile=Apache::File->new('/proc/loadavg');
+            $loadavg=<$loadfile>;
+        }
+        $loadavg =~ s/\s.*//g;
+        my $loadpercent=sprintf("%.1f",100*$loadavg/$loadlim);
+        my $userloadpercent=&Apache::lonnet::userload();
+
+# ---------------------------------------------------------- Are we overloaded?
+        if ((($userloadpercent>100.0)||($loadpercent>100.0))) {
+            my $unloaded=Apache::lonnet::spareserver($loadpercent,$userloadpercent,1,$form{'udom'});
+            if ($unloaded) {
+                &success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',
+                         undef,\%form);
+                $r->internal_redirect('/adm/switchserver?otherserver='.$unloaded.'&origurl='.$firsturl);
+                return OK;
+            }
+        }
+        &success($r,$form{'uname'},$form{'udom'},$authhost,$firsturl,undef,
+                 \%form);
+        return OK;
     }
-    return OK;
 }
 
 sub check_can_host {
     my ($r,$form,$authhost,$domdesc) = @_;
     return unless (ref($form) eq 'HASH');
     my $canhost = 1;
-    my @machinedoms = &Apache::lonnet::current_machine_domains();
+    my $lonhost = $r->dir_config('lonHostID');
     my $udom = $form->{'udom'};
-    unless (grep(/^\Q$udom\E/,@machinedoms)) {
-        my $defdom = &Apache::lonnet::default_login_domain();
-        my %defdomdefaults = &Apache::lonnet::get_domain_defaults($defdom);
+    my @intdoms;
+    my $internet_names = &Apache::lonnet::get_internet_names($lonhost);
+    if (ref($internet_names) eq 'ARRAY') {
+        @intdoms = @{$internet_names};
+    }
+    my $uprimary_id = &Apache::lonnet::domain($udom,'primary');
+    my $uint_dom = &Apache::lonnet::internet_dom($uprimary_id);
+    unless ($uint_dom ne '' && grep(/^\Q$uint_dom\E$/,@intdoms)) {
+        my $machine_dom = &Apache::lonnet::host_domain($lonhost);
+        my $hostname = &Apache::lonnet::hostname($lonhost);
+        my $serverhomeID = &Apache::lonnet::get_server_homeID($hostname);
+        my $serverhomedom = &Apache::lonnet::host_domain($serverhomeID);
+        my %defdomdefaults = &Apache::lonnet::get_domain_defaults($serverhomedom);
         my %udomdefaults = &Apache::lonnet::get_domain_defaults($udom);
         my $loncaparev;
         if ($authhost eq 'no_account_on_host') {
-            $loncaparev = &Apache::lonnet::get_server_loncaparev($defdom);
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($machine_dom);
         } else {
-            $loncaparev = &Apache::lonnet::get_server_loncaparev($defdom,$authhost);
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($machine_dom,$lonhost);
         }
-        $canhost = &Apache::lonnet::can_host_session($udom,$defdom,$loncaparev,$udomdefaults{'remotesessions'},$defdomdefaults{'hostedsessions'});
+        $canhost = &Apache::lonnet::can_host_session($udom,$lonhost,$loncaparev,
+                                                     $udomdefaults{'remotesessions'},
+                                                     $defdomdefaults{'hostedsessions'});
     }
     unless ($canhost) {
         if ($authhost eq 'no_account_on_host') {
-            my ($login_host,$hostname) = &choose_server($udom);
+            my ($login_host,$hostname) = &Apache::lonnet::choose_server($udom);
             &Apache::loncommon::content_type($r,'text/html');
             $r->send_http_header;
             if ($login_host ne '') {
@@ -457,33 +498,14 @@ sub check_can_host {
                           '<p>'.&mt('Currently a LON-CAPA server is not available within the [_1] domain for you to log-in to, to create an account.',$domdesc).'</p>'.
                           &Apache::loncommon::end_page());
             }
-            return OK;
         } else {
             &success($r,$form->{'uname'},$udom,$authhost,'noredirect',undef,
                      $form);
-            my ($otherserver) = &choose_server($udom);
+            my ($otherserver) = &Apache::lonnet::choose_server($udom);
             $r->internal_redirect('/adm/switchserver?otherserver='.$otherserver);
         }
     }
-}
-
-sub choose_server {
-    my ($udom) = @_;
-    my %domconfhash = &Apache::loncommon::get_domainconf($udom);
-    my %servers = &Apache::lonnet::get_servers($udom);
-    my $lowest_load = 30000;
-    my ($login_host,$hostname);
-    foreach my $lonhost (keys(%servers)) {
-        my $loginvia = $domconfhash{$udom.'.login.loginvia_'.$lonhost};
-        if ($loginvia eq '') {
-            ($login_host, $lowest_load) =
-            &Apache::lonnet::compare_server_load($lonhost, $login_host, $lowest_load);
-        }
-    }
-    if ($login_host ne '') {
-        $hostname = $servers{$login_host};
-    }
-    return ($login_host,$hostname);
+    return $canhost;
 }
 
 1;