--- loncom/interface/domainprefs.pm	2010/05/21 15:54:44	1.135
+++ loncom/interface/domainprefs.pm	2011/07/31 23:05:00	1.145
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Handler to set domain-wide configuration settings
 #
-# $Id: domainprefs.pm,v 1.135 2010/05/21 15:54:44 bisitz Exp $
+# $Id: domainprefs.pm,v 1.145 2011/07/31 23:05:00 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -140,7 +140,7 @@ autolimit
 
 =over
  
-- course requests will be processed autoatically up to a limit of
+- course requests will be processed automatically up to a limit of
 N requests for the course type for the particular requestor.
 If N is undefined, there is no limit to the number of course requests
 which a course owner may submit and have processed automatically. 
@@ -203,12 +203,12 @@ sub handler {
                 'directorysrch','usercreation','usermodification',
                 'contacts','defaults','scantron','coursecategories',
                 'serverstatuses','requestcourses','helpsettings',
-                'coursedefaults'],$dom);
+                'coursedefaults','usersessions'],$dom);
     my @prefs_order = ('rolecolors','login','defaults','quotas','autoenroll',
                        'autoupdate','autocreate','directorysrch','contacts',
                        'usercreation','usermodification','scantron',
                        'requestcourses','coursecategories','serverstatuses','helpsettings',
-                       'coursedefaults');
+                       'coursedefaults','usersessions');
     my %prefs = (
         'rolecolors' =>
                    { text => 'Default color schemes',
@@ -230,7 +230,7 @@ sub handler {
                     },
 
         'defaults' => 
-                    { text => 'Default authentication/language/timezone',
+                    { text => 'Default authentication/language/timezone/portal',
                       help => 'Domain_Configuration_LangTZAuth',
                       header => [{col1 => 'Setting',
                                   col2 => 'Value'}],
@@ -340,8 +340,10 @@ sub handler {
         'coursedefaults' => 
                  {text => 'Course/Community defaults',
                   help => 'Domain_Configuration_Course_Defaults',
-                  header => [{col1 => 'Setting',
-                              col2 => 'Value',}],
+                  header => [{col1 => 'Defaults which can be overridden in each course by a CC',
+                              col2 => 'Value',},
+                             {col1 => 'Defaults which can be overridden for each course by a DC',
+                              col2 => 'Value',},],
                  },
         'privacy' => 
                  {text   => 'User Privacy',
@@ -349,6 +351,16 @@ sub handler {
                   header => [{col1 => 'Setting',
                               col2 => 'Value',}],
                  },
+        'usersessions' =>
+                 {text  => 'User session hosting/offloading',
+                  help  => 'Domain_Configuration_User_Sessions',
+                  header => [{col1 => 'Domain server',
+                              col2 => 'Servers to offload sessions to when busy'},
+                             {col1 => 'Hosting of users from other domains',
+                              col2 => 'Rules'},
+                             {col1 => "Hosting domain's own users elsewhere",
+                              col2 => 'Rules'}],
+                 },
     );
     my %servers = &dom_servers($dom);
     if (keys(%servers) > 1) {
@@ -451,6 +463,8 @@ sub process_changes {
         $output = &modify_helpsettings($r,$dom,$confname,%domconfig);
     } elsif ($action eq 'coursedefaults') {
         $output = &modify_coursedefaults($dom,%domconfig);
+    } elsif ($action eq 'usersessions') {
+        $output = &modify_usersessions($dom,%domconfig);
     }
     return $output;
 }
@@ -476,16 +490,20 @@ sub print_config_box {
     }
     if ($numheaders > 1) {
         my $colspan = '';
+        my $rightcolspan = '';
         if (($action eq 'rolecolors') || ($action eq 'coursecategories') || ($action eq 'helpsettings')) {
             $colspan = ' colspan="2"';
         }
+        if ($action eq 'usersessions') {
+            $rightcolspan = ' colspan="3"'; 
+        }
         $output .= '
           <tr>
            <td>
             <table class="LC_nested">
              <tr class="LC_info_row">
               <td class="LC_left_item"'.$colspan.'>'.&mt($item->{'header'}->[0]->{'col1'}).'</td>
-              <td class="LC_right_item">'.&mt($item->{'header'}->[0]->{'col2'}).'</td>
+              <td class="LC_right_item"'.$rightcolspan.'>'.&mt($item->{'header'}->[0]->{'col2'}).'</td>
              </tr>';
         $rowtotal ++;
         if ($action eq 'autoupdate') {
@@ -503,8 +521,12 @@ sub print_config_box {
             $output .= &print_quotas($dom,$settings,\$rowtotal,$action);
         } elsif ($action eq 'helpsettings') {
             $output .= &print_helpsettings('top',$dom,$confname,$settings,\$rowtotal);
+        } elsif ($action eq 'usersessions') {
+            $output .= &print_usersessions('top',$dom,$settings,\$rowtotal); 
         } elsif ($action eq 'rolecolors') {
             $output .= &print_rolecolors($phase,'student',$dom,$confname,$settings,\$rowtotal);
+        } elsif ($action eq 'coursedefaults') {
+            $output .= &print_coursedefaults('top',$dom,$settings,\$rowtotal);
         }
         $output .= '
            </table>
@@ -566,6 +588,21 @@ sub print_config_box {
             $output .= &print_courserequestmail($dom,$settings,\$rowtotal);
         } elsif ($action eq 'helpsettings') {
             $output .= &print_helpsettings('bottom',$dom,$confname,$settings,\$rowtotal);
+        } elsif ($action eq 'usersessions') {
+            $output .= &print_usersessions('middle',$dom,$settings,\$rowtotal).'
+           </table>
+          </td>
+         </tr>
+         <tr>
+           <td>
+            <table class="LC_nested">
+             <tr class="LC_info_row">
+              <td class="LC_left_item"'.$colspan.'>'.&mt($item->{'header'}->[2]->{'col1'}).'</td>
+              <td class="LC_right_item">'.&mt($item->{'header'}->[2]->{'col2'}).'</td>      </tr>'.
+                       &print_usersessions('bottom',$dom,$settings,\$rowtotal);
+            $rowtotal ++;
+        } elsif ($action eq 'coursedefaults') {
+            $output .= &print_coursedefaults('bottom',$dom,$settings,\$rowtotal);
         } elsif ($action eq 'rolecolors') {
             $output .= &print_rolecolors($phase,'coordinator',$dom,$confname,$settings,\$rowtotal).'
            </table>
@@ -654,8 +691,6 @@ sub print_config_box {
             $output .= &print_serverstatuses($dom,$settings,\$rowtotal);
         } elsif ($action eq 'helpsettings') {
             $output .= &print_helpsettings('top',$dom,$confname,$settings,\$rowtotal);
-    	} elsif ($action eq 'coursedefaults') {
-            $output .= &print_coursedefaults($dom,$settings,\$rowtotal);
         }
     }
     $output .= '
@@ -849,7 +884,6 @@ sub print_login {
                                                   domlogo => 'Domain Logo',
                                                   login => 'Login box');
     my $itemcount = 1;
-    my ($css_class,$datatable);
     foreach my $item (@toggles) {
         $css_class = $itemcount%2?' class="LC_odd_row"':'';
         $datatable .=  
@@ -1869,24 +1903,23 @@ sub print_autocreate {
                   '<input type="radio" name="autocreate_xml"'.
                   $createon{'xml'}.' value="1" />'.&mt('Yes').'</label>&nbsp;'.
                   '<label><input type="radio" name="autocreate_xml"'.
-                  $createoff{'xml'}.' value="0" />'.&mt('No').'</label></span>';
+                  $createoff{'xml'}.' value="0" />'.&mt('No').'</label></span>'.
+                  '</td></tr><tr>'.
+                  '<td>'.&mt('Create pending requests for official courses (if validated)').'</td>'.
+                  '<td class="LC_right_item"><span class="LC_nobreak"><label>'.
+                  '<input type="radio" name="autocreate_req"'.
+                  $createon{'req'}.' value="1" />'.&mt('Yes').'</label>&nbsp;'.
+                  '<label><input type="radio" name="autocreate_req"'.
+                  $createoff{'req'}.' value="0" />'.&mt('No').'</label></span>';
     my ($numdc,$dctable) = &active_dc_picker($dom,$curr_dc);
     if ($numdc > 1) {
-        $datatable .= '</td><tr><td>'.
-                      &mt('XML files processed as: (choose Dom. Coord.)'). 
-                      '</td><td class="LC_left_item">'.$dctable.'</td></tr>'.
-                      '<tr class="LC_odd_row">';
+        $datatable .= '</td></tr><tr class="LC_odd_row"><td>'.
+                      &mt('Course creation processed as: (choose Dom. Coord.)').
+                      '</td><td class="LC_left_item">'.$dctable.'</td></tr>';
         $$rowtotal ++ ;
     } else {
-        $datatable .= '</td></tr><tr>';
+        $datatable .= $dctable.'</td></tr>';
     }
-    $datatable .= '<td>'.&mt('Create pending requests for official courses (if validated)').'</td>'.
-                  '<td class="LC_right_item"><span class="LC_nobreak"><label>'.
-                  '<input type="radio" name="autocreate_req"'.
-                  $createon{'req'}.' value="1" />'.&mt('Yes').'</label>&nbsp;'.
-                  '<label><input type="radio" name="autocreate_req"'.
-                  $createoff{'req'}.' value="0" />'.&mt('No').'</label></span></td>'.
-                  '</tr>';
     return $datatable;
 }
 
@@ -2077,7 +2110,7 @@ sub print_contacts {
                       '<input type="text" name="'.$type.'_others" '.
                       'value="'.$otheremails{$type}.'"  />';
         if ($type eq 'helpdeskmail') {
-            $datatable .= '<br />'.&mt('Bcc').':'.('&nbsp;'x6).
+            $datatable .= '<br />'.&mt('Bcc:').('&nbsp;'x6).
                           '<input type="text" name="'.$type.'_bcc" '.
                           'value="'.$bccemails{$type}.'"  />';
         }
@@ -2226,22 +2259,379 @@ sub radiobutton_prefs {
 }
 
 sub print_coursedefaults {
-    my ($dom,$settings,$rowtotal) = @_;
+    my ($position,$dom,$settings,$rowtotal) = @_;
     my ($css_class,$datatable);
     my $itemcount = 1;
-    my (%checkedon,%checkedoff,%choices,%defaultchecked,@toggles);
-    %choices =
-        &Apache::lonlocal::texthash (
-            canuse_pdfforms => 'Course/Community users can create/upload PDF forms',
-    );
-    %defaultchecked = ('canuse_pdfforms' => 'off');
-    @toggles = ('canuse_pdfforms',);
-    ($datatable,$itemcount) = &radiobutton_prefs($settings,\@toggles,\%defaultchecked,
+    if ($position eq 'top') {
+        my (%checkedon,%checkedoff,%choices,%defaultchecked,@toggles);
+        %choices =
+            &Apache::lonlocal::texthash (
+                canuse_pdfforms => 'Course/Community users can create/upload PDF forms',
+        );
+        %defaultchecked = ('canuse_pdfforms' => 'off');
+        @toggles = ('canuse_pdfforms',);
+        ($datatable,$itemcount) = &radiobutton_prefs($settings,\@toggles,\%defaultchecked,
                                                  \%choices,$itemcount);
+        $$rowtotal += $itemcount;
+    } else {
+        $css_class = $itemcount%2 ? ' class="LC_odd_row"' : '';
+        my %choices =
+            &Apache::lonlocal::texthash (
+                anonsurvey_threshold => 'Responder count needed before showing submissions for anonymous surveys',
+        );
+        my $currdefresponder;
+        if (ref($settings) eq 'HASH') {
+            $currdefresponder = $settings->{'anonsurvey_threshold'};
+        }
+        if (!$currdefresponder) {
+            $currdefresponder = 10;
+        } elsif ($currdefresponder < 1) {
+            $currdefresponder = 1;
+        }
+        $datatable .=
+               '<tr'.$css_class.'><td><span class="LC_nobreak">'.$choices{'anonsurvey_threshold'}.
+                '</span></td>'.
+                '<td class="LC_right_item"><span class="LC_nobreak">'.
+                '<input type="text" name="anonsurvey_threshold"'.
+                ' value="'.$currdefresponder.'" size="5" /></span>'.
+                '</td></tr>';
+    }
+    return $datatable;
+}
+
+sub print_usersessions {
+    my ($position,$dom,$settings,$rowtotal) = @_;
+    my ($css_class,$datatable,%checked,%choices);
+    my (%by_ip,%by_location,@intdoms);
+    &build_location_hashes(\@intdoms,\%by_ip,\%by_location);
+
+    my @alldoms = &Apache::lonnet::all_domains();
+    my %uniques = &Apache::lonnet::get_unique_servers(\@alldoms);
+    my %servers = &dom_servers($dom);
+    my $itemcount = 1;
+    if ($position eq 'top') {
+        if (keys(%uniques) > 1) {
+            my %spareid = &current_offloads_to($dom,$settings,\%servers);
+            $datatable .= &spares_row(\%servers,\%spareid,\%uniques,$rowtotal);
+        } else {
+            $datatable .= '<tr'.$css_class.'><td colspan="2">'.
+                          &mt('Nothing to set here, as the cluster to which this domain belongs only contains this server.');
+        }
+    } else {
+        if (keys(%by_location) == 0) {
+            $datatable .= '<tr'.$css_class.'><td colspan="2">'.
+                          &mt('Nothing to set here, as the cluster to which this domain belongs only contains this institution.');
+        } else {
+            my %lt = &usersession_titles();
+            my $numinrow = 5;
+            my $prefix;
+            my @types;
+            if ($position eq 'bottom') {
+                $prefix = 'remote';
+                @types = ('version','excludedomain','includedomain');
+            } else {
+                $prefix = 'hosted';
+                @types = ('excludedomain','includedomain');
+            }
+            my (%current,%checkedon,%checkedoff);
+            my @lcversions = &Apache::lonnet::all_loncaparevs();
+            my @locations = sort(keys(%by_location));
+            foreach my $type (@types) {
+                $checkedon{$type} = '';
+                $checkedoff{$type} = ' checked="checked"';
+            }
+            if (ref($settings) eq 'HASH') {
+                if (ref($settings->{$prefix}) eq 'HASH') {
+                    foreach my $key (keys(%{$settings->{$prefix}})) {
+                        $current{$key} = $settings->{$prefix}{$key};
+                        if ($key eq 'version') {
+                            if ($current{$key} ne '') {
+                                $checkedon{$key} = ' checked="checked"';
+                                $checkedoff{$key} = '';
+                            }
+                        } elsif (ref($current{$key}) eq 'ARRAY') {
+                            $checkedon{$key} = ' checked="checked"';
+                            $checkedoff{$key} = '';
+                        }
+                    }
+                }
+            }
+            foreach my $type (@types) {
+                next if ($type ne 'version' && !@locations);
+                $css_class = $itemcount%2 ? ' class="LC_odd_row"' : '';
+                $datatable .= '<tr'.$css_class.'>
+                               <td><span class="LC_nobreak">'.$lt{$type}.'</span><br />
+                               <span class="LC_nobreak">&nbsp;
+                               <label><input type="radio" name="'.$prefix.'_'.$type.'_inuse" '.$checkedoff{$type}.' value="0" />'.&mt('Not in use').'</label>&nbsp;
+                               <label><input type="radio" name="'.$prefix.'_'.$type.'_inuse" '.$checkedon{$type}.' value="1" />'.&mt('In use').'</label></span></td><td>';
+                if ($type eq 'version') {
+                    my $selector = '<select name="'.$prefix.'_version">';
+                    foreach my $version (@lcversions) {
+                        my $selected = '';
+                        if ($current{'version'} eq $version) {
+                            $selected = ' selected="selected"';
+                        }
+                        $selector .= ' <option value="'.$version.'"'.
+                                     $selected.'>'.$version.'</option>';
+                    }
+                    $selector .= '</select> ';
+                    $datatable .= &mt('remote server must be version: [_1] or later',$selector);
+                } else {
+                    $datatable.= '<div><input type="button" value="'.&mt('check all').'" '.
+                                 'onclick="javascript:checkAll(document.display.'.$prefix.'_'.$type.')"'.
+                                 ' />'.('&nbsp;'x2).
+                                 '<input type="button" value="'.&mt('uncheck all').'" '.
+                                 'onclick="javascript:uncheckAll(document.display.'.$prefix.'_'.$type.')" />'.
+                                 "\n".
+                                 '</div><div><table>';
+                    my $rem;
+                    for (my $i=0; $i<@locations; $i++) {
+                        my ($showloc,$value,$checkedtype);
+                        if (ref($by_location{$locations[$i]}) eq 'ARRAY') {
+                            my $ip = $by_location{$locations[$i]}->[0];
+                            if (ref($by_ip{$ip}) eq 'ARRAY') {
+                                 $value = join(':',@{$by_ip{$ip}});
+                                $showloc = join(', ',@{$by_ip{$ip}});
+                                if (ref($current{$type}) eq 'ARRAY') {
+                                    foreach my $loc (@{$by_ip{$ip}}) {  
+                                        if (grep(/^\Q$loc\E$/,@{$current{$type}})) {
+                                            $checkedtype = ' checked="checked"';
+                                            last;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                        $rem = $i%($numinrow);
+                        if ($rem == 0) {
+                            if ($i > 0) {
+                                $datatable .= '</tr>';
+                            }
+                            $datatable .= '<tr>';
+                        }
+                        $datatable .= '<td class="LC_left_item">'.
+                                      '<span class="LC_nobreak"><label>'.
+                                      '<input type="checkbox" name="'.$prefix.'_'.$type.
+                                      '" value="'.$value.'"'.$checkedtype.' />'.$showloc.
+                                      '</label></span></td>';
+                    }
+                    $rem = @locations%($numinrow);
+                    my $colsleft = $numinrow - $rem;
+                    if ($colsleft > 1 ) {
+                        $datatable .= '<td colspan="'.$colsleft.'" class="LC_left_item">'.
+                                      '&nbsp;</td>';
+                    } elsif ($colsleft == 1) {
+                        $datatable .= '<td class="LC_left_item">&nbsp;</td>';
+                    }
+                    $datatable .= '</tr></table>';
+                }
+                $datatable .= '</td></tr>';
+                $itemcount ++;
+            }
+        }
+    }
+    $$rowtotal += $itemcount;
+    return $datatable;
+}
+
+sub build_location_hashes {
+    my ($intdoms,$by_ip,$by_location) = @_;
+    return unless((ref($intdoms) eq 'ARRAY') && (ref($by_ip) eq 'HASH') &&
+                  (ref($by_location) eq 'HASH')); 
+    my %iphost = &Apache::lonnet::get_iphost();
+    my $primary_id = &Apache::lonnet::domain($env{'request.role.domain'},'primary');
+    my $primary_ip = &Apache::lonnet::get_host_ip($primary_id);
+    if (ref($iphost{$primary_ip}) eq 'ARRAY') {
+        foreach my $id (@{$iphost{$primary_ip}}) {
+            my $intdom = &Apache::lonnet::internet_dom($id);
+            unless(grep(/^\Q$intdom\E$/,@{$intdoms})) {
+                push(@{$intdoms},$intdom);
+            }
+        }
+    }
+    foreach my $ip (keys(%iphost)) {
+        if (ref($iphost{$ip}) eq 'ARRAY') {
+            foreach my $id (@{$iphost{$ip}}) {
+                my $location = &Apache::lonnet::internet_dom($id);
+                if ($location) {
+                    next if (grep(/^\Q$location\E$/,@{$intdoms}));
+                    if (ref($by_ip->{$ip}) eq 'ARRAY') {
+                        unless(grep(/^\Q$location\E$/,@{$by_ip->{$ip}})) {
+                            push(@{$by_ip->{$ip}},$location);
+                        }
+                    } else {
+                        $by_ip->{$ip} = [$location];
+                    }
+                }
+            }
+        }
+    }
+    foreach my $ip (sort(keys(%{$by_ip}))) {
+        if (ref($by_ip->{$ip}) eq 'ARRAY') {
+            @{$by_ip->{$ip}} = sort(@{$by_ip->{$ip}});
+            my $first = $by_ip->{$ip}->[0];
+            if (ref($by_location->{$first}) eq 'ARRAY') {
+                unless (grep(/^\Q$ip\E$/,@{$by_location->{$first}})) {
+                    push(@{$by_location->{$first}},$ip);
+                }
+            } else {
+                $by_location->{$first} = [$ip];
+            }
+        }
+    }
+    return;
+}
+
+sub current_offloads_to {
+    my ($dom,$settings,$servers) = @_;
+    my (%spareid,%otherdomconfigs);
+    if ((ref($settings) eq 'HASH') && (ref($servers) eq 'HASH')) {
+        foreach my $lonhost (sort(keys(%{$servers}))) {
+            my $gotspares;
+            if (ref($settings->{'spares'}) eq 'HASH') {
+                if (ref($settings->{'spares'}{$lonhost}) eq 'HASH') {
+                    $spareid{$lonhost}{'primary'} = $settings->{'spares'}{$lonhost}{'primary'};
+                    $spareid{$lonhost}{'default'} = $settings->{'spares'}{$lonhost}{'default'};
+                    $gotspares = 1;
+                }
+            }
+            unless ($gotspares) {
+                my $gotspares;
+                my $serverhomeID =
+                    &Apache::lonnet::get_server_homeID($servers->{$lonhost});
+                my $serverhomedom =
+                    &Apache::lonnet::host_domain($serverhomeID);
+                if ($serverhomedom ne $dom) {
+                    if (ref($otherdomconfigs{$serverhomedom} eq 'HASH')) {
+                        if (ref($otherdomconfigs{$serverhomedom}{'usersessions'}) eq 'HASH') {
+                            if (ref($otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}) eq 'HASH') {
+                                $spareid{$lonhost}{'primary'} = $otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}{'primary'};
+                                $spareid{$lonhost}{'default'} = $otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}{'default'};
+                                $gotspares = 1;
+                            }
+                        }
+                    } else {
+                        $otherdomconfigs{$serverhomedom} =
+                            &Apache::lonnet::get_dom('configuration',['usersessions'],$serverhomedom);
+                        if (ref($otherdomconfigs{$serverhomedom}) eq 'HASH') {
+                            if (ref($otherdomconfigs{$serverhomedom}{'usersessions'}) eq 'HASH') {
+                                if (ref($otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}) eq 'HASH') {
+                                    if (ref($otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}{$lonhost}) eq 'HASH') {
+                                        $spareid{$lonhost}{'primary'} = $otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}{'primary'};
+                                        $spareid{$lonhost}{'default'} = $otherdomconfigs{$serverhomedom}{'usersessions'}{'spares'}{'default'};
+                                        $gotspares = 1;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            unless ($gotspares) {
+                if ($lonhost eq $Apache::lonnet::perlvar{'lonHostID'}) {
+                    $spareid{$lonhost}{'primary'} = $Apache::lonnet::spareid{'primary'};
+                    $spareid{$lonhost}{'default'} = $Apache::lonnet::spareid{'default'};
+               } else {
+                    my $server_hostname = &Apache::lonnet::hostname($lonhost);
+                    my $server_homeID = &Apache::lonnet::get_server_homeID($server_hostname);
+                    if ($server_homeID eq $Apache::lonnet::perlvar{'lonHostID'}) {
+                        $spareid{$lonhost}{'primary'} = $Apache::lonnet::spareid{'primary'};
+                        $spareid{$lonhost}{'default'} = $Apache::lonnet::spareid{'default'};
+                    } else {
+                        my %requested;
+                        $requested{'spareid'} = 'HASH';
+                        my %returnhash = &Apache::lonnet::get_remote_globals($lonhost,\%requested);
+                        my $spareshash = $returnhash{'spareid'};
+                        if (ref($spareshash) eq 'HASH') {
+                            $spareid{$lonhost}{'primary'} = $spareshash->{'primary'};
+                            $spareid{$lonhost}{'default'} = $spareshash->{'default'};
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return %spareid;
+}
+
+sub spares_row {
+    my ($servers,$spareid,$uniques,$rowtotal) = @_;
+    my $css_class;
+    my $numinrow = 4;
+    my $itemcount = 1;
+    my $datatable;
+    if ((ref($servers) eq 'HASH') && (ref($spareid) eq 'HASH')) {
+        foreach my $server (sort(keys(%{$servers}))) {
+            $css_class = $itemcount%2 ? ' class="LC_odd_row"' : '';
+            $datatable .= '<tr'.$css_class.'>
+                           <td rowspan="2">
+                            <span class="LC_nobreak"><b>'.$server.'</b> when busy, offloads to:</span></td>';
+            my (%current,%canselect);
+            if (ref($spareid->{$server}) eq 'HASH') {
+                foreach my $type ('primary','default') {
+                    if (ref($spareid->{$server}{$type}) eq 'ARRAY') {
+                        my @spares = @{$spareid->{$server}{$type}};
+                        if (@spares > 0) {
+                            $current{$type} .= '<table>';
+                            for (my $i=0;  $i<@spares; $i++) {
+                                my $rem = $i%($numinrow);
+                                if ($rem == 0) {
+                                    if ($i > 0) {
+                                        $current{$type} .= '</tr>';
+                                    }
+                                    $current{$type} .= '<tr>';
+                                }
+                                $current{$type} .= '<td><label><input type="checkbox" name="spare_'.$type.'_'.$server.'" checked="checked" value="'.$spareid->{$server}{$type}[$i].'" />&nbsp;'.
+                                                   $spareid->{$server}{$type}[$i].
+                                                   '</label></td>';
+                            }
+                            $current{$type} .= '</tr></table>';
+                        }
+                    }
+                    if ($current{$type} eq '') {
+                        $current{$type} = &mt('None specified');
+                    }
+                    $canselect{$type} =
+                        &newspare_select($server,$type,$spareid->{$server}{$type},$uniques);
+                }
+            }
+            $datatable .= '<td><i>'.&mt('primary').'</i><td>'.$current{'primary'}.'</td>'.
+                          '<td>'.&mt('Add new [_1]primary[_2]:','<i>','</i>').'&nbsp;'.
+                          $canselect{'primary'}.'</td></tr>'.
+                          '<tr'.$css_class.'>'.
+                          '<td><i>'.&mt('default').'</i></td>'.
+                          '<td>'.$current{'default'}.'</td>'.
+                          '<td>'.&mt('Add new [_1]default[_2]:','<i>','</i>').'&nbsp;'.
+                          $canselect{'default'}.'</td></tr>';
+            $itemcount ++;
+        }
+    }
     $$rowtotal += $itemcount;
     return $datatable;
 }
 
+sub newspare_select {
+    my ($server,$type,$currspares,$uniques) = @_;
+    my $output;
+    if (ref($uniques) eq 'HASH') {
+        if (keys(%{$uniques}) > 1) {
+            $output = '<select name="newspare_'.$type.'_'.$server.'">'."\n".
+                      '<option value="" selected ="selected">'.&mt('Select').'</option>'."\n";
+            foreach my $lonhost (sort(keys(%{$uniques}))) {
+                next if ($lonhost eq $server);
+                if (ref($currspares) eq 'ARRAY') {
+                    if (@{$currspares} > 0) {
+                        next if (grep(/^\Q$lonhost\E$/,@{$currspares}));
+                    }
+                }
+                $output .= '<option value="'.$lonhost.'">'.$lonhost.'</option>'."\n";
+            }
+            $output .= '<select>';
+        }
+    }
+    return $output;
+}
+
 sub contact_titles {
     my %titles = &Apache::lonlocal::texthash (
                    'supportemail' => 'Support E-mail address',
@@ -2613,9 +3003,9 @@ sub print_usermodification {
 sub print_defaults {
     my ($dom,$rowtotal) = @_;
     my @items = ('auth_def','auth_arg_def','lang_def','timezone_def',
-                 'datelocale_def');
+                 'datelocale_def','portal_def');
     my %domdefaults = &Apache::lonnet::get_domain_defaults($dom);
-    my $titles = &defaults_titles();
+    my $titles = &defaults_titles($dom);
     my $rownum = 0;
     my ($datatable,$css_class);
     foreach my $item (@items) {
@@ -2652,8 +3042,12 @@ sub print_defaults {
             my $includeempty = 1;
             $datatable .= &Apache::loncommon::select_datelocale($item,$domdefaults{$item},undef,$includeempty);
         } else {
+            my $size;
+            if ($item eq 'portal_def') {
+                $size = ' size="25"';
+            }
             $datatable .= '<input type="text" name="'.$item.'" value="'.
-                          $domdefaults{$item}.'" />';
+                          $domdefaults{$item}.'"'.$size.' />';
         }
         $datatable .= '</td></tr>';
         $rownum ++;
@@ -2663,13 +3057,25 @@ sub print_defaults {
 }
 
 sub defaults_titles {
+    my ($dom) = @_;
     my %titles = &Apache::lonlocal::texthash (
                    'auth_def'      => 'Default authentication type',
                    'auth_arg_def'  => 'Default authentication argument',
                    'lang_def'      => 'Default language',
                    'timezone_def'  => 'Default timezone',
                    'datelocale_def' => 'Default locale for dates',
+                   'portal_def'     => 'Portal/Default URL',
                  );
+    if ($dom) {
+        my $uprimary_id = &Apache::lonnet::domain($dom,'primary');
+        my $uint_dom = &Apache::lonnet::internet_dom($uprimary_id);
+        my $protocol = $Apache::lonnet::protocol{$uprimary_id};
+        $protocol = 'http' if ($protocol ne 'https');
+        if ($uint_dom) {
+            $titles{'portal_def'} .= ' '.&mt('(for example: [_1])',$protocol.'://loncapa.'.
+                                         $uint_dom);
+        }
+    }
     return (\%titles);
 }
 
@@ -4435,12 +4841,12 @@ sub modify_quotas {
                     $changes{'notify'}{'approval'} = 1;
                 }
             } else {
-                if ($domconfig{$action}{'notify'}{'approval'}) {
+                if ($confhash{'notify'}{'approval'}) {
                     $changes{'notify'}{'approval'} = 1;
                 }
             }
         } else {
-            if ($domconfig{$action}{'notify'}{'approval'}) {
+            if ($confhash{'notify'}{'approval'}) {
                 $changes{'notify'}{'approval'} = 1;
             }
         }
@@ -4761,7 +5167,7 @@ sub modify_autoupdate {
                         middlename => 'Middle Name',
                         generation => 'Generation',
                       );
-    my $othertitle = &mt('All users');
+    $othertitle = &mt('All users');
     if (keys(%{$usertypes}) >  0) {
         $othertitle = &mt('Other users');
     }
@@ -5805,7 +6211,7 @@ sub modify_defaults {
     my ($dom,$r) = @_;
     my ($resulttext,$mailmsgtxt,%newvalues,%changes,@errors);
     my %domdefaults = &Apache::lonnet::get_domain_defaults($dom);
-    my @items = ('auth_def','auth_arg_def','lang_def','timezone_def','datelocale_def');
+    my @items = ('auth_def','auth_arg_def','lang_def','timezone_def','datelocale_def','portal_def');
     my @authtypes = ('internal','krb4','krb5','localauth');
     foreach my $item (@items) {
         $newvalues{$item} = $env{'form.'.$item};
@@ -5841,6 +6247,12 @@ sub modify_defaults {
                     push(@errors,$item);
                 }
             }
+        } elsif ($item eq 'portal_def') {
+            if ($newvalues{$item} ne '') {
+                unless ($newvalues{$item} =~ /^https?\:\/\/(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])\/?$/) {
+                    push(@errors,$item);
+                }
+            }
         }
         if (grep(/^\Q$item\E$/,@errors)) {
             $newvalues{$item} = $domdefaults{$item};
@@ -6257,7 +6669,6 @@ sub modify_serverstatuses {
     my %serverstatushash =  (
                                 serverstatuses => \%newserverstatus,
                             );
-    my %changes;
     foreach my $type (@pages) {
         foreach my $setting ('namedusers','machines') {
             my (@current,@new);
@@ -6487,6 +6898,18 @@ sub modify_coursedefaults {
             }
             $defaultshash{'coursedefaults'}{$item} = $env{'form.'.$item};
         }
+        my $currdefresponder = $domconfig{'coursedefaults'}{'anonsurvey_threshold'};
+        my $newdefresponder = $env{'form.anonsurvey_threshold'};
+        $newdefresponder =~ s/\D//g;
+        if ($newdefresponder eq '' || $newdefresponder < 1) {
+            $newdefresponder = 1;
+        }
+        $defaultshash{'coursedefaults'}{'anonsurvey_threshold'} = $newdefresponder;
+        if ($currdefresponder ne $newdefresponder) {
+            unless ($currdefresponder eq '' && $newdefresponder == 10) {
+                $changes{'anonsurvey_threshold'} = 1;
+            }
+        }
     }
     my $putresult = &Apache::lonnet::put_dom('configuration',\%defaultshash,
                                              $dom);
@@ -6506,6 +6929,8 @@ sub modify_coursedefaults {
                     } else {
                         $resulttext .= '<li>'.&mt('Course/Community users can create/upload PDF forms set to "off"').'</li>';
                     }
+                } elsif ($item eq 'anonsurvey_threshold') {
+                        $resulttext .= '<li>'.&mt('Responder count required for display of anonymous survey submissions set to [_1].',$defaultshash{'coursedefaults'}{'anonsurvey_threshold'}).'</li>';
                 }
             }
             $resulttext .= '</ul>';
@@ -6519,6 +6944,264 @@ sub modify_coursedefaults {
     return $resulttext;
 }
 
+sub modify_usersessions {
+    my ($dom,%domconfig) = @_;
+    my @hostingtypes = ('version','excludedomain','includedomain');
+    my @offloadtypes = ('primary','default');
+    my %types = (
+                  remote => \@hostingtypes,
+                  hosted => \@hostingtypes,
+                  spares => \@offloadtypes,
+                );
+    my @prefixes = ('remote','hosted','spares');
+    my @lcversions = &Apache::lonnet::all_loncaparevs();
+    my (%by_ip,%by_location,@intdoms);
+    &build_location_hashes(\@intdoms,\%by_ip,\%by_location);
+    my @locations = sort(keys(%by_location));
+    my (%defaultshash,%changes);
+    foreach my $prefix (@prefixes) {
+        $defaultshash{'usersessions'}{$prefix} = {};
+    }
+    my %domdefaults = &Apache::lonnet::get_domain_defaults($dom);
+    my $resulttext;
+    my %iphost = &Apache::lonnet::get_iphost();
+    foreach my $prefix (@prefixes) {
+        next if ($prefix eq 'spares');
+        foreach my $type (@{$types{$prefix}}) {
+            my $inuse = $env{'form.'.$prefix.'_'.$type.'_inuse'};
+            if ($type eq 'version') {
+                my $value = $env{'form.'.$prefix.'_'.$type};
+                my $okvalue;
+                if ($value ne '') {
+                    if (grep(/^\Q$value\E$/,@lcversions)) {
+                        $okvalue = $value;
+                    }
+                }
+                if (ref($domconfig{'usersessions'}) eq 'HASH') {
+                    if (ref($domconfig{'usersessions'}{$prefix}) eq 'HASH') {
+                        if ($domconfig{'usersessions'}{$prefix}{$type} ne '') {
+                            if ($inuse == 0) {
+                                $changes{$prefix}{$type} = 1;
+                            } else {
+                                if ($okvalue ne $domconfig{'usersessions'}{$prefix}{$type}) {
+                                    $changes{$prefix}{$type} = 1;
+                                }
+                                if ($okvalue ne '') {
+                                    $defaultshash{'usersessions'}{$prefix}{$type} = $okvalue;
+                                } 
+                            }
+                        } else {
+                            if (($inuse == 1) && ($okvalue ne '')) {
+                                $defaultshash{'usersessions'}{$prefix}{$type} = $okvalue;
+                                $changes{$prefix}{$type} = 1;
+                            }
+                        }
+                    } else {
+                        if (($inuse == 1) && ($okvalue ne '')) {
+                            $defaultshash{'usersessions'}{$prefix}{$type} = $okvalue;
+                            $changes{$prefix}{$type} = 1;
+                        }
+                    }
+                } else {
+                    if (($inuse == 1) && ($okvalue ne '')) {
+                        $defaultshash{'usersessions'}{$prefix}{$type} = $okvalue;
+                        $changes{$prefix}{$type} = 1;
+                    }
+                }
+            } else {
+                my @vals = &Apache::loncommon::get_env_multiple('form.'.$prefix.'_'.$type);
+                my @okvals;
+                foreach my $val (@vals) {
+                    if ($val =~ /:/) {
+                        my @items = split(/:/,$val);
+                        foreach my $item (@items) {
+                            if (ref($by_location{$item}) eq 'ARRAY') {
+                                push(@okvals,$item);
+                            }
+                        }
+                    } else {
+                        if (ref($by_location{$val}) eq 'ARRAY') {
+                            push(@okvals,$val);
+                        }
+                    }
+                }
+                @okvals = sort(@okvals);
+                if (ref($domconfig{'usersessions'}) eq 'HASH') {
+                    if (ref($domconfig{'usersessions'}{$prefix}) eq 'HASH') {
+                        if (ref($domconfig{'usersessions'}{$prefix}{$type}) eq 'ARRAY') {
+                            if ($inuse == 0) {
+                                $changes{$prefix}{$type} = 1; 
+                            } else {
+                                $defaultshash{'usersessions'}{$prefix}{$type} = \@okvals;
+                                my @changed = &Apache::loncommon::compare_arrays($domconfig{'usersessions'}{$prefix}{$type},$defaultshash{'usersessions'}{$prefix}{$type});
+                                if (@changed > 0) {
+                                    $changes{$prefix}{$type} = 1;
+                                }
+                            }
+                        } else {
+                            if ($inuse == 1) {
+                                $defaultshash{'usersessions'}{$prefix}{$type} = \@okvals;
+                                $changes{$prefix}{$type} = 1;
+                            }
+                        } 
+                    } else {
+                        if ($inuse == 1) {
+                            $defaultshash{'usersessions'}{$prefix}{$type} = \@okvals;
+                            $changes{$prefix}{$type} = 1;
+                        }
+                    }
+                } else {
+                    if ($inuse == 1) {
+                        $defaultshash{'usersessions'}{$prefix}{$type} = \@okvals;
+                        $changes{$prefix}{$type} = 1;
+                    }
+                }
+            }
+        }
+    }
+
+    my @alldoms = &Apache::lonnet::all_domains();
+    my %uniques = &Apache::lonnet::get_unique_servers(\@alldoms);
+    my %servers = &dom_servers($dom);
+    my %spareid = &current_offloads_to($dom,$domconfig{'usersessions'},\%servers);
+    my $savespares;
+
+    foreach my $lonhost (sort(keys(%servers))) {
+        my $serverhomeID =
+            &Apache::lonnet::get_server_homeID($servers{$lonhost});
+        $defaultshash{'usersessions'}{'spares'}{$lonhost} = {};
+        my %spareschg;
+        foreach my $type (@{$types{'spares'}}) {
+            my @okspares;
+            my @checked = &Apache::loncommon::get_env_multiple('form.spare_'.$type.'_'.$lonhost);
+            foreach my $server (@checked) {
+                unless (($server eq $lonhost) || ($server eq $serverhomeID)) {
+                    if ($uniques{$server}) {
+                        push(@okspares,$server);
+                    }
+                }
+            }
+            my $new = $env{'form.newspare_'.$type.'_'.$lonhost};
+            my $newspare;
+            if (($new ne '') && ($uniques{$new})) {
+                unless (($new eq $lonhost) || ($new eq $serverhomeID)) {
+                    $newspare = $new;
+                    $spareschg{$type} = 1;
+                }
+            }
+            if (ref($spareid{$lonhost}) eq 'HASH') {
+                if (ref($spareid{$lonhost}{$type}) eq 'ARRAY') {
+                    my @diffs = &Apache::loncommon::compare_arrays($domconfig{'usersessions'}{'spares'}{$lonhost}{$type},\@okspares);
+                    if (@diffs > 0) {
+                        $spareschg{$type} = 1;
+                    } elsif ($new ne '') {
+                        $spareschg{$type} = 1;
+                    }
+                }
+            }
+            my @spares = sort(@okspares,$newspare);
+            $defaultshash{'usersessions'}{'spares'}{$lonhost}{$type} = \@spares;
+        }
+        if (keys(%spareschg) > 0) {
+            $changes{'spares'}{$lonhost} = \%spareschg;
+        }
+    }
+
+    if (ref($domconfig{'usersessions'}) eq 'HASH') {
+        if (ref($domconfig{'usersessions'}{'spares'}) eq 'HASH') {
+            if (ref($changes{'spares'}) eq 'HASH') {
+                if (keys(%{$changes{'spares'}}) > 0) {
+                    $savespares = 1;
+                }
+            }
+        } else {
+            $savespares = 1;
+        }
+    }
+
+    if (keys(%changes) > 0) {
+        my $putresult = &Apache::lonnet::put_dom('configuration',\%defaultshash,
+                                                 $dom);
+        if ($putresult eq 'ok') {
+            if (ref($defaultshash{'usersessions'}) eq 'HASH') {
+                if (ref($defaultshash{'usersessions'}{'remote'}) eq 'HASH') {
+                    $domdefaults{'remotesessions'} = $defaultshash{'usersessions'}{'remote'};
+                }
+                if (ref($defaultshash{'usersessions'}{'hosted'}) eq 'HASH') {
+                    $domdefaults{'hostedsessions'} = $defaultshash{'usersessions'}{'hosted'};
+                }
+            }
+            my $cachetime = 24*60*60;
+            &Apache::lonnet::do_cache_new('domdefaults',$dom,\%domdefaults,$cachetime);
+            my %lt = &usersession_titles();
+            $resulttext = &mt('Changes made:').'<ul>';
+            foreach my $prefix (@prefixes) {
+                if (ref($changes{$prefix}) eq 'HASH') {
+                    $resulttext .= '<li>'.$lt{$prefix}.'<ul>';
+                    if ($prefix eq 'spares') {
+                        if (ref($changes{$prefix}) eq 'HASH') {
+                            foreach my $lonhost (sort(keys(%{$changes{$prefix}}))) {
+                                $resulttext .= '<li><b>'.$lonhost.'</b> ';
+                                if (ref($changes{$prefix}{$lonhost}) eq 'HASH') {
+                                    foreach my $type (@{$types{$prefix}}) {
+                                        if ($changes{$prefix}{$lonhost}{$type}) {
+                                            my $offloadto = &mt('None');
+                                            if (ref($defaultshash{'usersessions'}{'spares'}{$lonhost}{$type}) eq 'ARRAY') {
+                                                if (@{$defaultshash{'usersessions'}{'spares'}{$lonhost}{$type}} > 0) {   
+                                                    $offloadto = join(', ',@{$defaultshash{'usersessions'}{'spares'}{$lonhost}{$type}});
+                                                }
+                                            }
+                                            $resulttext .= &mt('[_1] set to: [_2]','<i>'.$lt{'type'}.'</i>',$offloadto).('&nbsp;'x3);
+                                        }
+                                    }
+                                }
+                                $resulttext .= '</li>';
+                            }
+                        }
+                    } else {
+                        foreach my $type (@{$types{$prefix}}) {
+                            if (defined($changes{$prefix}{$type})) {
+                                my $newvalue;
+                                if (ref($defaultshash{'usersessions'}) eq 'HASH') {
+                                    if (ref($defaultshash{'usersessions'}{$prefix})) {
+                                        if ($type eq 'version') {
+                                            $newvalue = $defaultshash{'usersessions'}{$prefix}{$type};
+                                        } elsif (ref($defaultshash{'usersessions'}{$prefix}{$type}) eq 'ARRAY') {
+                                            if (@{$defaultshash{'usersessions'}{$prefix}{$type}} > 0) {
+                                                $newvalue = join(', ',@{$defaultshash{'usersessions'}{$prefix}{$type}});
+                                            }
+                                        }
+                                    }
+                                }
+                                if ($newvalue eq '') {
+                                    if ($type eq 'version') {
+                                        $resulttext .= '<li>'.&mt('[_1] set to: off',$lt{$type}).'</li>';
+                                    } else {
+                                        $resulttext .= '<li>'.&mt('[_1] set to: none',$lt{$type}).'</li>';
+                                    }
+                                } else {
+                                    if ($type eq 'version') {
+                                        $newvalue .= ' '.&mt('(or later)'); 
+                                    }
+                                    $resulttext .= '<li>'.&mt('[_1] set to: [_2].',$lt{$type},$newvalue).'</li>';
+                                }
+                            }
+                        }
+                    }
+                    $resulttext .= '</ul>';
+                }
+            }
+            $resulttext .= '</ul>';
+        } else {
+            $resulttext = '<span class="LC_error">'.
+                          &mt('An error occurred: [_1]',$putresult).'</span>';
+        }
+    } else {
+        $resulttext =  &mt('No changes made to settings for user session hosting/offloading.');
+    }
+    return $resulttext;
+}
+
 sub recurse_check {
     my ($chkcats,$categories,$depth,$name) = @_;
     if (ref($chkcats->[$depth]{$name}) eq 'ARRAY') {
@@ -6662,4 +7345,18 @@ sub active_dc_picker {
     return ($numdcs,$datatable);
 }
 
+sub usersession_titles {
+    return &Apache::lonlocal::texthash(
+               hosted => 'Hosting of sessions for users from other domains on servers in this domain',
+
+               remote => 'Hosting of sessions for users in this domain on servers in other domains',
+               spares => 'Servers offloaded to, when busy',
+               version => 'LON-CAPA version requirement',
+               excludedomain => 'Allow all, but exclude specific domains',
+               includedomain => 'Deny all, but include specific domains',
+               primary => 'Primary (checked first)',
+               default => 'Default', 
+           );
+}
+
 1;