--- loncom/Attic/lonc 2001/11/28 21:19:58 1.21
+++ loncom/Attic/lonc 2002/02/19 22:51:13 1.28
@@ -5,6 +5,30 @@
# provides persistent TCP connections to the other servers in the network
# through multiplexed domain sockets
#
+# $Id: lonc,v 1.28 2002/02/19 22:51:13 www Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
# PID in subdir logs/lonc.pid
# kill kills
# HUP restarts
@@ -15,8 +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
@@ -29,6 +57,8 @@ use Socket;
use Fcntl;
use Tie::RefHash;
use Crypt::IDEA;
+use Net::Ping;
+use LWP::UserAgent();
my $status='';
my $lastlog='';
@@ -46,9 +76,47 @@ sub catchexception {
$childmaxattempts=5;
+# -------------------------------------- Routines to see if other box available
+
+sub online {
+ my $host=shift;
+ my $p=Net::Ping->new("tcp",20);
+ 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;
$SIG{__DIE__}=\&catchexception;
# ------------------------------------ Read httpd access.conf and get variables
@@ -92,8 +160,12 @@ open (CONFIG,"$perlvar{'lonTabDir'}/host
while ($configline=<CONFIG>) {
my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
chomp($ip);
- $hostip{$id}=$ip;
+ if ($ip) {
+ $hostip{$id}=$ip;
+ $hostname{$id}=$name;
+ }
}
+
close(CONFIG);
# -------------------------------------------------------- Routines for forking
@@ -117,15 +189,19 @@ sub REAPER { # ta
unlink($port);
}
-sub HUNTSMAN { # signal handler for SIGINT
- local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
- map {
+sub hangup {
+ foreach (keys %children) {
$wasserver=$children{$_};
&status("Closing $wasserver");
&logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
&status("Kill PID $_ for $wasserver");
kill ('INT',$_);
- } keys %children;
+ }
+}
+
+sub HUNTSMAN { # signal handler for SIGINT
+ local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
+ &hangup();
my $execdir=$perlvar{'lonDaemons'};
unlink("$execdir/logs/lonc.pid");
&logthis("<font color=red>CRITICAL: Shutting down</font>");
@@ -134,13 +210,7 @@ sub HUNTSMAN { # si
sub HUPSMAN { # signal handler for SIGHUP
local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
- map {
- $wasserver=$children{$_};
- &status("Closing $wasserver");
- &logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
- &status("Kill PID $_ for $wasserver");
- kill ('INT',$_);
- } keys %children;
+ &hangup();
&logthis("<font color=red>CRITICAL: Restarting</font>");
unlink("$execdir/logs/lonc.pid");
my $execdir=$perlvar{'lonDaemons'};
@@ -151,23 +221,17 @@ 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 {
&logthis("USR1: Trying to establish connections again");
- foreach $thisserver (keys %hostip) {
- $answer=subreply("ping",$thisserver);
- &logthis("USR1: Ping $thisserver "
- ."(pid >$childpid{$thisserver}<, $childatt{thisserver} attempts): "
- ." >$answer<");
- }
%childatt=();
&checkchildren();
}
@@ -272,7 +336,9 @@ $SIG{HUP}=$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");
@@ -291,13 +357,19 @@ 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 $childmaxattempts attempts)</font>");
+ }
+
}
}
}
@@ -423,7 +495,7 @@ if ($cipher=new IDEA $cipherkey) {
@allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
closedir(DIRHANDLE);
my $dfname;
- map {
+ foreach (@allbuffered) {
&status("Sending delayed $conserver $_");
$dfname="$path/$_";
&logthis($dfname);
@@ -464,7 +536,7 @@ if ($cipher=new IDEA $cipherkey) {
&logthis("Delayed $cmd to $conserver: >$answer<");
&logperm("S:$conserver:$bcmd");
}
- } @allbuffered;
+ }
# ------------------------------------------------------- Listen to UNIX socket
&status("Opening socket $conserver");
@@ -669,3 +741,50 @@ 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