--- loncom/Attic/lonc	2001/11/29 18:57:46	1.22
+++ 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 1.22 2001/11/29 18:57:46 www Exp $
+# $Id: lonc,v 1.26 2002/02/19 21:12:22 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -39,8 +39,12 @@
 # 2/8,7/25 Gerd Kortemeyer
 # 12/05 Scott Harrison
 # 12/05 Gerd Kortemeyer
+# YEAR=2001
 # 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
@@ -53,6 +57,8 @@ use Socket;
 use Fcntl;
 use Tie::RefHash;
 use Crypt::IDEA;
+use Net::Ping;
+use LWP::UserAgent();
 
 my $status='';
 my $lastlog='';
@@ -70,9 +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
@@ -143,13 +187,13 @@ sub REAPER {                        # ta
 
 sub HUNTSMAN {                      # signal handler for SIGINT
     local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
-    map {
+    foreach (keys %children) {
         $wasserver=$children{$_};
         &status("Closing $wasserver");
         &logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
         &status("Kill PID $_ for $wasserver");
 	kill ('INT',$_);
-    } keys %children;
+    }
     my $execdir=$perlvar{'lonDaemons'};
     unlink("$execdir/logs/lonc.pid");
     &logthis("<font color=red>CRITICAL: Shutting down</font>");
@@ -158,13 +202,13 @@ sub HUNTSMAN {                      # si
 
 sub HUPSMAN {                      # signal handler for SIGHUP
     local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
-    map {
+    foreach (keys %children) {
         $wasserver=$children{$_};
         &status("Closing $wasserver");
         &logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
         &status("Kill PID $_ for $wasserver");
 	kill ('INT',$_);
-    } keys %children;
+    }
     &logthis("<font color=red>CRITICAL: Restarting</font>");
     unlink("$execdir/logs/lonc.pid");
     my $execdir=$perlvar{'lonDaemons'};
@@ -175,13 +219,13 @@ sub checkchildren {
     &initnewstatus();
     &logstatus();
     &logthis('Going to check on the children');
-    map {
+    foreach (sort keys %children) {
 	sleep 1;
         unless (kill 'USR1' => $_) {
 	    &logthis ('Child '.$_.' is dead');
             &logstatus($$.' is dead');
         } 
-    } sort keys %children;
+    }
 }
 
 sub USRMAN {
@@ -296,7 +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");
@@ -315,13 +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 $childmaxattempts attempts)</font>");
+           } 
+               
         }       
     }
 }
@@ -447,7 +499,7 @@ if ($cipher=new IDEA $cipherkey) {
     @allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
     closedir(DIRHANDLE);
     my $dfname;
-    map {
+    foreach (@allbuffered) {
         &status("Sending delayed $conserver $_");
         $dfname="$path/$_";
         &logthis($dfname);
@@ -488,7 +540,7 @@ if ($cipher=new IDEA $cipherkey) {
             &logthis("Delayed $cmd to $conserver: >$answer<");
             &logperm("S:$conserver:$bcmd");
         }        
-    } @allbuffered;
+    }
 
 # ------------------------------------------------------- Listen to UNIX socket
 &status("Opening socket $conserver");
@@ -693,3 +745,50 @@ sub nonblock {
             or die "Can't make socket nonblocking: $!\n";
 }
 
+# ----------------------------------- POD (plain old documentation, CPAN style)
+
+=head1 NAME
+
+lonc - LON TCP-MySQL-Server Daemon for handling database requests.
+
+=head1 SYNOPSIS
+
+Should only be run as user=www.  This is a command-line script which
+is invoked by loncron.
+
+=head1 DESCRIPTION
+
+Provides persistent TCP connections to the other servers in the network
+through multiplexed domain sockets
+
+ PID in subdir logs/lonc.pid
+ kill kills
+ HUP restarts
+ USR1 tries to open connections again
+
+=head1 README
+
+Not yet written.
+
+=head1 PREREQUISITES
+
+POSIX
+IO::Socket
+IO::Select
+IO::File
+Socket
+Fcntl
+Tie::RefHash
+Crypt::IDEA
+
+=head1 COREQUISITES
+
+=head1 OSNAMES
+
+linux
+
+=head1 SCRIPT CATEGORIES
+
+Server/Process
+
+=cut