--- loncom/Attic/lonc	2002/02/06 14:15:37	1.25
+++ loncom/Attic/lonc	2002/02/19 21:12:22	1.26
@@ -5,7 +5,7 @@
 # provides persistent TCP connections to the other servers in the network
 # through multiplexed domain sockets
 #
-# $Id: lonc,v 1.25 2002/02/06 14:15:37 albertel Exp $
+# $Id: lonc,v 1.26 2002/02/19 21:12:22 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -43,6 +43,8 @@
 # 01/10/01 Scott Harrison
 # 03/14/01,03/15,06/12,11/26,11/27,11/28 Gerd Kortemeyer
 # 12/20 Scott Harrison
+# YEAR=2002
+# 2/19/02
 # 
 # based on nonforker from Perl Cookbook
 # - server who multiplexes without forking
@@ -55,6 +57,8 @@ use Socket;
 use Fcntl;
 use Tie::RefHash;
 use Crypt::IDEA;
+use Net::Ping;
+use LWP::UserAgent();
 
 my $status='';
 my $lastlog='';
@@ -72,9 +76,47 @@ sub catchexception {
 
 $childmaxattempts=5;
 
+# -------------------------------------- Routines to see if other box available
+
+sub online {
+    my $host=shift;
+    my $p=Net::Ping->new("tcp",10);
+    my $online=$p->ping("$host");
+    $p->close();
+    undef ($p);
+    return $online;
+}
+
+sub connected {
+    my ($local,$remote)=@_;
+    $local=~s/\W//g;
+    $remote=~s/\W//g;
+
+    unless ($hostname{$local}) { return 'local_unknown'; }
+    unless ($hostname{$remote}) { return 'remote_unknown'; }
+
+    unless (&online($hostname{$local})) { return 'local_offline'; }
+
+    my $ua=new LWP::UserAgent;
+    
+    my $request=new HTTP::Request('GET',
+      "http://".$hostname{$local}.'/cgi-bin/ping.pl?'.$remote);
+
+    my $response=$ua->request($request);
+
+    unless ($response->is_success) { return 'local_error'; }
+
+    my $reply=$response->content;
+    $reply=(split("\n",$reply))[0];
+    $reply=~s/\W//g;
+    if ($reply ne $remote) { return $reply; }
+    return 'ok';
+}
+
+
 # -------------------------------- Set signal handlers to record abnormal exits
 
-$SIG{'QUIT'}=\&catchexception;
+$SIG{QUIT}=\&catchexception;
 $SIG{__DIE__}=\&catchexception;
 
 # ------------------------------------ Read httpd access.conf and get variables
@@ -298,7 +340,9 @@ $SIG{HUP}=$SIG{USR1}='IGNORE';
 &status("Forking ...");
 
 foreach $thisserver (keys %hostip) {
-    make_new_child($thisserver);
+    if (&online($hostname{$thisserver})) {
+       make_new_child($thisserver);
+    }
 }
 
 &logthis("Done starting initial servers");
@@ -317,13 +361,19 @@ while (1) {
     &status("Woke up");
     foreach $thisserver (keys %hostip) {
         if (!$childpid{$thisserver}) {
-	    if ($childatt{$thisserver}<$childmaxattempts) {
+	    if (($childatt{$thisserver}<$childmaxattempts) &&
+                (&online($hostname{$thisserver}))) {
 	       $childatt{$thisserver}++;
                &logthis(
    "<font color=yellow>INFO: Trying to reconnect for $thisserver "
   ."($childatt{$thisserver} of $childmaxattempts attempts)</font>"); 
                make_new_child($thisserver);
-	    }
+	   } else {
+               &logthis(
+   "<font color=yellow>INFO: Skipping $thisserver "
+  ."($childatt{$thisserver} of $childmaxattempts attempts)</font>");
+           } 
+               
         }       
     }
 }