[LON-CAPA-cvs] cvs: loncom / lond /auth switchserver.pm /lonnet/perl lonnet.pm

[albertel]

albertel		Sat Sep 29 00:03:52 2007 EDT

  Modified files:              
    /loncom	lond 
    /loncom/auth	switchserver.pm 
    /loncom/lonnet/perl	lonnet.pm 
  Log:
  - when offloading a user session to a different server, check the remote
    servers for an existing session and pick one of those first
    - new lond command that checks if a session file exists for a specific user
    - new lonnet routines to probe servers for one
  
  
  
Index: loncom/lond
diff -u loncom/lond:1.381 loncom/lond:1.382
--- loncom/lond:1.381	Wed Sep 12 16:29:13 2007
+++ loncom/lond	Sat Sep 29 00:03:39 2007
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.381 2007/09/12 20:29:13 raeburn Exp $
+# $Id: lond,v 1.382 2007/09/29 04:03:39 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -59,7 +59,7 @@
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.381 $'; #' stupid emacs
+my $VERSION='$Revision: 1.382 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -2095,6 +2095,37 @@
 &register_handler("renameuserfile", \&rename_user_file_handler, 0,1,0);
 
 #
+#  Checks if the specified user has an active session on the server
+#  return ok if so, not_found if not
+#
+# Parameters:
+#   cmd      - The request keyword that dispatched to tus.
+#   tail     - The tail of the request (colon separated parameters).
+#   client   - Filehandle open on the client.
+# Return:
+#    1.
+sub user_has_session_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my ($udom, $uname) = map { &unescape($_) } (split(/:/, $tail));
+    
+    &logthis("Looking for $udom $uname");
+    opendir(DIR,$perlvar{'lonIDsDir'});
+    my $filename;
+    while ($filename=readdir(DIR)) {
+	last if ($filename=~/^\Q$uname\E_\d+_\Q$udom\E_/);
+    }
+    if ($filename) {
+	&Reply($client, "ok\n", "$cmd:$tail");
+    } else {
+	&Failure($client, "not_found\n", "$cmd:$tail");
+    }
+    return 1;
+
+}
+&register_handler("userhassession", \&user_has_session_handler, 0,1,0);
+
+#
 #  Authenticate access to a user file by checking that the token the user's 
 #  passed also exists in their session file
 #
Index: loncom/auth/switchserver.pm
diff -u loncom/auth/switchserver.pm:1.16 loncom/auth/switchserver.pm:1.17
--- loncom/auth/switchserver.pm:1.16	Fri Sep  7 22:43:33 2007
+++ loncom/auth/switchserver.pm	Sat Sep 29 00:03:46 2007
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Switch Servers Handler
 #
-# $Id: switchserver.pm,v 1.16 2007/09/08 02:43:33 raeburn Exp $
+# $Id: switchserver.pm,v 1.17 2007/09/29 04:03:46 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -83,8 +83,15 @@
 					    ['otherserver','role']);
 
     my $switch_to=&Apache::lonnet::hostname($env{'form.otherserver'});
-    if (!$env{'form.otherserver'}) {
-	$env{'form.otherserver'}=&Apache::lonnet::spareserver(30000,undef,1);
+    if (! $env{'form.otherserver'}) {
+	$env{'form.otherserver'} =	
+	    &Apache::lonnet::find_existing_session($env{'user.domain'},
+						   $env{'user.name'});
+	if (! $env{'form.otherserver'}) {
+	    $env{'form.otherserver'} = 
+		&Apache::lonnet::spareserver(30000,undef,1);
+	}
+
 	$switch_to=&Apache::lonnet::hostname($env{'form.otherserver'});
     }
 
Index: loncom/lonnet/perl/lonnet.pm
diff -u loncom/lonnet/perl/lonnet.pm:1.913 loncom/lonnet/perl/lonnet.pm:1.914
--- loncom/lonnet/perl/lonnet.pm:1.913	Mon Sep 24 20:21:12 2007
+++ loncom/lonnet/perl/lonnet.pm	Sat Sep 29 00:03:51 2007
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.913 2007/09/25 00:21:12 albertel Exp $
+# $Id: lonnet.pm,v 1.914 2007/09/29 04:03:51 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -582,6 +582,27 @@
     }
     return ($spare_server,$lowest_load);
 }
+
+# --------------------------- ask offload servers if user already has a session
+sub find_existing_session {
+    my ($udom,$uname) = @_;
+    foreach my $try_server (@{ $spareid{'primary'} },
+			    @{ $spareid{'default'} }) {
+	return $try_server if (&has_user_session($try_server, $udom, $uname));
+    }
+    return;
+}
+
+# -------------------------------- ask if server already has a session for user
+sub has_user_session {
+    my ($lonid,$udom,$uname) = @_;
+    my $result = &reply(join(':','userhassession',
+			     map {&escape($_)} ($udom,$uname)),$lonid);
+    return 1 if ($result eq 'ok');
+
+    return 0;
+}
+
 # --------------------------------------------- Try to change a user's password
 
 sub changepass {