--- loncom/Attic/lonc 2001/03/15 20:25:20 1.15
+++ loncom/Attic/lonc 2002/02/19 21:49:12 1.27
@@ -5,6 +5,30 @@
# provides persistent TCP connections to the other servers in the network
# through multiplexed domain sockets
#
+# $Id: lonc,v 1.27 2002/02/19 21:49:12 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 Gerd Kortemeyer
+# 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 +57,11 @@ use Socket;
use Fcntl;
use Tie::RefHash;
use Crypt::IDEA;
+use Net::Ping;
+use LWP::UserAgent();
+
+my $status='';
+my $lastlog='';
# grabs exception and records it to log before exiting
sub catchexception {
@@ -41,11 +74,49 @@ sub catchexception {
die($@);
}
-$childmaxattempts=10;
+$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;
$SIG{__DIE__}=\&catchexception;
# ------------------------------------ Read httpd access.conf and get variables
@@ -90,7 +161,9 @@ while ($configline=<CONFIG>) {
my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
chomp($ip);
$hostip{$id}=$ip;
+ $hostname{$id}=$name;
}
+
close(CONFIG);
# -------------------------------------------------------- Routines for forking
@@ -114,9 +187,19 @@ sub REAPER { # ta
unlink($port);
}
+sub hangup {
+ foreach (keys %children) {
+ $wasserver=$children{$_};
+ &status("Closing $wasserver");
+ &logthis('Closing '.$wasserver.': '.&subreply('exit',$wasserver));
+ &status("Kill PID $_ for $wasserver");
+ kill ('INT',$_);
+ }
+}
+
sub HUNTSMAN { # signal handler for SIGINT
local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
- kill 'INT' => keys %children;
+ &hangup();
my $execdir=$perlvar{'lonDaemons'};
unlink("$execdir/logs/lonc.pid");
&logthis("<font color=red>CRITICAL: Shutting down</font>");
@@ -125,22 +208,30 @@ sub HUNTSMAN { # si
sub HUPSMAN { # signal handler for SIGHUP
local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
- kill 'INT' => keys %children;
+ &hangup();
&logthis("<font color=red>CRITICAL: Restarting</font>");
unlink("$execdir/logs/lonc.pid");
my $execdir=$perlvar{'lonDaemons'};
exec("$execdir/lonc"); # here we go again
}
+sub checkchildren {
+ &initnewstatus();
+ &logstatus();
+ &logthis('Going to check on the children');
+ foreach (sort keys %children) {
+ sleep 1;
+ unless (kill 'USR1' => $_) {
+ &logthis ('Child '.$_.' is dead');
+ &logstatus($$.' is dead');
+ }
+ }
+}
+
sub USRMAN {
&logthis("USR1: Trying to establish connections again");
- foreach $thisserver (keys %hostip) {
- $answer=subreply("ping",$thisserver);
- &logthis("USR1: Ping $thisserver "
- ."(pid >$childpid{$thisserver}<, $childatt{thisserver} attempts): "
- ." >$answer<");
- }
%childatt=();
+ &checkchildren();
}
# -------------------------------------------------- Non-critical communication
@@ -153,10 +244,20 @@ sub subreply {
Type => SOCK_STREAM,
Timeout => 10)
or return "con_lost";
- print $sclient "$cmd\n";
- my $answer=<$sclient>;
- chomp($answer);
- if (!$answer) { $answer="con_lost"; }
+
+
+ $SIG{ALRM}=sub { die "timeout" };
+ $SIG{__DIE__}='DEFAULT';
+ eval {
+ alarm(10);
+ print $sclient "$cmd\n";
+ $answer=<$sclient>;
+ chomp($answer);
+ alarm(0);
+ };
+ if ((!$answer) || ($@=~/timeout/)) { $answer="con_lost"; }
+ $SIG{ALRM}='DEFAULT';
+ $SIG{__DIE__}=\&catchexception;
} else { $answer='self_reply'; }
return $answer;
}
@@ -169,6 +270,7 @@ sub logthis {
my $fh=IO::File->new(">>$execdir/logs/lonc.log");
my $now=time;
my $local=localtime($now);
+ $lastlog=$local.': '.$message;
print $fh "$local ($$): $message\n";
}
@@ -181,6 +283,31 @@ sub logperm {
my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
print $fh "$now:$message:$local\n";
}
+# ------------------------------------------------------------------ Log status
+
+sub logstatus {
+ my $docdir=$perlvar{'lonDocRoot'};
+ my $fh=IO::File->new(">>$docdir/lon-status/loncstatus.txt");
+ print $fh $$."\t".$status."\t".$lastlog."\n";
+}
+
+sub initnewstatus {
+ my $docdir=$perlvar{'lonDocRoot'};
+ my $fh=IO::File->new(">$docdir/lon-status/loncstatus.txt");
+ my $now=time;
+ my $local=localtime($now);
+ print $fh "LONC status $local - parent $$\n\n";
+}
+
+# -------------------------------------------------------------- Status setting
+
+sub status {
+ my $what=shift;
+ my $now=time;
+ my $local=localtime($now);
+ $status=$local.': '.$what;
+}
+
# ---------------------------------------------------- Fork once and dissociate
@@ -204,8 +331,12 @@ $SIG{HUP}=$SIG{USR1}='IGNORE';
# Fork off our children, one for every server
+&status("Forking ...");
+
foreach $thisserver (keys %hostip) {
- make_new_child($thisserver);
+ if (&online($hostname{$thisserver})) {
+ make_new_child($thisserver);
+ }
}
&logthis("Done starting initial servers");
@@ -218,17 +349,25 @@ $SIG{USR1} = \&USRMAN;
# And maintain the population.
while (1) {
+ &status("Sleeping");
sleep; # wait for a signal (i.e., child's death)
# See who died and start new one
+ &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>");
+ }
+
}
}
}
@@ -257,7 +396,8 @@ sub make_new_child {
} else {
# Child can *not* return from this subroutine.
$SIG{INT} = 'DEFAULT'; # make SIGINT kill us as it did before
-
+ $SIG{USR1}= \&logstatus;
+
# unblock signals
sigprocmask(SIG_UNBLOCK, $sigset)
or die "Can't unblock SIGINT for fork: $!\n";
@@ -267,7 +407,11 @@ sub make_new_child {
$port = "$perlvar{'lonSockDir'}/$conserver";
unlink($port);
+
# ---------------------------------------------------- Client to network server
+
+&status("Opening TCP: $conserver");
+
unless (
$remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
PeerPort => $perlvar{'londPort'},
@@ -280,20 +424,47 @@ unless (
sleep($st);
exit;
};
-# --------------------------------------- Send a ping to make other end do USR1
+# ----------------------------------------------------------------- Init dialog
+
+&status("Init dialogue: $conserver");
+
+ $SIG{ALRM}=sub { die "timeout" };
+ $SIG{__DIE__}='DEFAULT';
+ eval {
+ alarm(60);
print $remotesock "init\n";
$answer=<$remotesock>;
print $remotesock "$answer";
$answer=<$remotesock>;
chomp($answer);
+ alarm(0);
+ };
+ $SIG{ALRM}='DEFAULT';
+ $SIG{__DIE__}=\&catchexception;
+
+ if ($@=~/timeout/) {
+ &logthis("Timed out during init: $conserver");
+ exit;
+ }
+
+
&logthis("Init reply for $conserver: >$answer<");
+if ($answer ne 'ok') {
+ my $st=120+int(rand(240));
+ &logthis(
+"<font color=blue>WARNING: Init failed $conserver ($st secs)</font>");
+ sleep($st);
+ exit;
+}
sleep 5;
+&status("Ponging $conserver");
print $remotesock "pong\n";
$answer=<$remotesock>;
chomp($answer);
&logthis("Pong reply for $conserver: >$answer<");
# ----------------------------------------------------------- Initialize cipher
+&status("Initialize cipher: $conserver");
print $remotesock "ekey\n";
my $buildkey=<$remotesock>;
my $key=$conserver.$perlvar{'lonHostID'};
@@ -315,14 +486,15 @@ if ($cipher=new IDEA $cipherkey) {
}
# ----------------------------------------- We're online, send delayed messages
-
+ &status("Checking for delayed messages");
my @allbuffered;
my $path="$perlvar{'lonSockDir'}/delayed";
opendir(DIRHANDLE,$path);
@allbuffered=grep /\.$conserver$/, readdir DIRHANDLE;
closedir(DIRHANDLE);
my $dfname;
- map {
+ foreach (@allbuffered) {
+ &status("Sending delayed $conserver $_");
$dfname="$path/$_";
&logthis($dfname);
my $wcmd;
@@ -345,18 +517,27 @@ if ($cipher=new IDEA $cipherkey) {
}
$cmd="enc:$cmdlength:$encrequest\n";
}
-
+ $SIG{ALRM}=sub { die "timeout" };
+ $SIG{__DIE__}='DEFAULT';
+ eval {
+ alarm(60);
print $remotesock "$cmd\n";
$answer=<$remotesock>;
chomp($answer);
- if ($answer ne '') {
+ alarm(0);
+ };
+ $SIG{ALRM}='DEFAULT';
+ $SIG{__DIE__}=\&catchexception;
+
+ if (($answer ne '') && ($@!~/timeout/)) {
unlink("$dfname");
&logthis("Delayed $cmd to $conserver: >$answer<");
&logperm("S:$conserver:$bcmd");
}
- } @allbuffered;
+ }
# ------------------------------------------------------- Listen to UNIX socket
+&status("Opening socket $conserver");
unless (
$server = IO::Socket::UNIX->new(Local => $port,
Type => SOCK_STREAM,
@@ -394,11 +575,11 @@ while (1) {
# check for new information on the connections we have
# anything to read or accept?
- foreach $client ($select->can_read(1)) {
+ foreach $client ($select->can_read(0.1)) {
if ($client == $server) {
# accept a new connection
-
+ &status("Accept new connection: $conserver");
$client = $server->accept();
$select->add($client);
nonblock($client);
@@ -413,6 +594,7 @@ while (1) {
delete $outbuffer{$client};
delete $ready{$client};
+ &status("Idle $conserver");
$select->remove($client);
close $client;
next;
@@ -497,8 +679,27 @@ sub handle {
}
$request="enc:$cmdlength:$encrequest\n";
}
+# --------------------------------------------------------------- Main exchange
+ $SIG{ALRM}=sub { die "timeout" };
+ $SIG{__DIE__}='DEFAULT';
+ eval {
+ alarm(300);
+ &status("Sending $conserver: $request");
print $remotesock "$request";
+ &status("Waiting for reply from $conserver: $request");
$answer=<$remotesock>;
+ &status("Received reply: $request");
+ alarm(0);
+ };
+ if ($@=~/timeout/) {
+ $answer='';
+ &logthis(
+ "<font color=red>CRITICAL: Timeout $conserver: $request</font>");
+ }
+ $SIG{ALRM}='DEFAULT';
+ $SIG{__DIE__}=\&catchexception;
+
+
if ($answer) {
if ($answer =~ /^enc/) {
my ($cmd,$cmdlength,$encinput)=split(/:/,$answer);
@@ -520,6 +721,7 @@ sub handle {
# ===================================================== Done processing request
}
delete $ready{$client};
+ &status("Completed $conserver: $request");
# -------------------------------------------------------------- End non-forker
}
# ---------------------------------------------------------- End make_new_child
@@ -537,3 +739,50 @@ 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