version 1.10, 2003/06/24 02:46:04
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version 1.19, 2003/08/19 09:31:46
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# Copyright Michigan State University Board of Trustees |
# Copyright Michigan State University Board of Trustees |
# |
# |
# This file is part of the LearningOnline Network with CAPA (LON-CAPA). |
# This file is part of the LearningOnline Network with CAPA (LON-CAPA). |
# |
## LON-CAPA is free software; you can redistribute it and/or modify |
# LON-CAPA is free software; you can redistribute it and/or modify |
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# it under the terms of the GNU General Public License as published by |
# it under the terms of the GNU General Public License as published by |
# the Free Software Foundation; either version 2 of the License, or |
# the Free Software Foundation; either version 2 of the License, or |
# (at your option) any later version. |
# (at your option) any later version. |
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Line 26
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# http://www.lon-capa.org/ |
# http://www.lon-capa.org/ |
# |
# |
# |
# |
# new lonc handles n requestors spread out bver m connections to londs. |
# new lonc handles n request out bver m connections to londs. |
# This module is based on the Event class. |
# This module is based on the Event class. |
# Development iterations: |
# Development iterations: |
# - Setup basic event loop. (done) |
# - Setup basic event loop. (done) |
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Line 45
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# Change log: |
# Change log: |
# $Log$ |
# $Log$ |
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# Revision 1.19 2003/08/19 09:31:46 foxr |
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# Get socket directory from configuration rather than the old hard coded test |
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# way that I forgot to un-hard code. |
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# |
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# Revision 1.18 2003/08/06 09:52:29 foxr |
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# Also needed to remember to fail in-flight transactions if their sends fail. |
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# |
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# Revision 1.17 2003/08/03 00:44:31 foxr |
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# 1. Correct handling of connection failure: Assume it means the host is |
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# unreachable and fail all of the queued transactions. Note that the |
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# inflight transactions should fail on their own time due either to timeout |
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# or send/receive failures. |
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# 2. Correct handling of logs for forced death signals. Pull the signal |
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# from the event watcher. |
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# |
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# Revision 1.16 2003/07/29 02:33:05 foxr |
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# Add SIGINT processing to child processes to toggle annoying trace mode |
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# on/off.. will try to use this to isolate the compute boud process issue. |
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# |
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# Revision 1.15 2003/07/15 02:07:05 foxr |
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# Added code for lonc/lond transaction timeouts. Who knows if it works right. |
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# The intent is for a timeout to fail any transaction in progress and kill |
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# off the sockt that timed out. |
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# |
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# Revision 1.14 2003/07/03 02:10:18 foxr |
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# Get all of the signals to work correctly. |
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# |
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# Revision 1.13 2003/07/02 01:31:55 foxr |
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# Added kill -HUP logic (restart). |
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# |
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# Revision 1.11 2003/06/25 01:54:44 foxr |
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# Fix more problems with transaction failure. |
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# |
# Revision 1.10 2003/06/24 02:46:04 foxr |
# Revision 1.10 2003/06/24 02:46:04 foxr |
# Put a limit on the number of times we'll retry a connection. |
# Put a limit on the number of times we'll retry a connection. |
# Start getting the signal stuff put in as well...note that need to get signals |
# Start getting the signal stuff put in as well...note that need to get signals |
Line 68 use lib "/home/httpd/lib/perl/";
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Line 100 use lib "/home/httpd/lib/perl/";
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use lib "/home/foxr/newloncapa/types"; |
use lib "/home/foxr/newloncapa/types"; |
use Event qw(:DEFAULT ); |
use Event qw(:DEFAULT ); |
use POSIX qw(:signal_h); |
use POSIX qw(:signal_h); |
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use POSIX; |
use IO::Socket; |
use IO::Socket; |
use IO::Socket::INET; |
use IO::Socket::INET; |
use IO::Socket::UNIX; |
use IO::Socket::UNIX; |
Line 86 use LONCAPA::HashIterator;
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Line 119 use LONCAPA::HashIterator;
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# |
# |
# Disable all signals we might receive from outside for now. |
# Disable all signals we might receive from outside for now. |
# |
# |
$SIG{QUIT} = IGNORE; |
#$SIG{QUIT} = IGNORE; |
$SIG{HUP} = IGNORE; |
#$SIG{HUP} = IGNORE; |
$SIG{USR1} = IGNORE; |
#$SIG{USR1} = IGNORE; |
$SIG{INT} = IGNORE; |
#$SIG{INT} = IGNORE; |
$SIG{CHLD} = IGNORE; |
#$SIG{CHLD} = IGNORE; |
$SIG{__DIE__} = IGNORE; |
#$SIG{__DIE__} = IGNORE; |
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# Read the httpd configuration file to get perl variables |
# Read the httpd configuration file to get perl variables |
Line 110 my $MaxConnectionCount = 10; # Will get
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Line 143 my $MaxConnectionCount = 10; # Will get
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my $ClientConnection = 0; # Uniquifier for client events. |
my $ClientConnection = 0; # Uniquifier for client events. |
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my $DebugLevel = 0; |
my $DebugLevel = 0; |
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my $NextDebugLevel= 10; # So Sigint can toggle this. |
my $IdleTimeout= 3600; # Wait an hour before pruning connections. |
my $IdleTimeout= 3600; # Wait an hour before pruning connections. |
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# |
# |
# The variables below are only used by the child processes. |
# The variables below are only used by the child processes. |
# |
# |
my $RemoteHost; # Name of host child is talking to. |
my $RemoteHost; # Name of host child is talking to. |
my $UnixSocketDir= "/home/httpd/sockets"; |
my $UnixSocketDir= $perlvar{'lonSockDir'} |
my $IdleConnections = Stack->new(); # Set of idle connections |
my $IdleConnections = Stack->new(); # Set of idle connections |
my %ActiveConnections; # Connections to the remote lond. |
my %ActiveConnections; # Connections to the remote lond. |
my %ActiveTransactions; # LondTransactions in flight. |
my %ActiveTransactions; # LondTransactions in flight. |
Line 125 my $WorkQueue = Queue->new(); # Qu
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Line 159 my $WorkQueue = Queue->new(); # Qu
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my $ConnectionCount = 0; |
my $ConnectionCount = 0; |
my $IdleSeconds = 0; # Number of seconds idle. |
my $IdleSeconds = 0; # Number of seconds idle. |
my $Status = ""; # Current status string. |
my $Status = ""; # Current status string. |
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my $RecentLogEntry = ""; |
my $ConnectionRetries=5; # Number of connection retries allowed. |
my $ConnectionRetries=5; # Number of connection retries allowed. |
my $ConnectionRetriesLeft=5; # Number of connection retries remaining. |
my $ConnectionRetriesLeft=5; # Number of connection retries remaining. |
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Line 201 sub Log {
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Line 236 sub Log {
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my $execdir = $perlvar{'lonDaemons'}; |
my $execdir = $perlvar{'lonDaemons'}; |
my $fh = IO::File->new(">>$execdir/logs/lonc.log"); |
my $fh = IO::File->new(">>$execdir/logs/lonc.log"); |
my $msg = sprintf($finalformat, $message); |
my $msg = sprintf($finalformat, $message); |
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$RecentLogEntry = $msg; |
print $fh $msg; |
print $fh $msg; |
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Line 244 sub Debug {
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Line 280 sub Debug {
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my $level = shift; |
my $level = shift; |
my $message = shift; |
my $message = shift; |
if ($level <= $DebugLevel) { |
if ($level <= $DebugLevel) { |
print $message." host = ".$RemoteHost."\n"; |
Log("INFO", "-Debug- $message host = $RemotHost"); |
} |
} |
} |
} |
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Line 274 sub ShowStatus {
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Line 310 sub ShowStatus {
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=pod |
=pod |
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=head 2 SocketTimeout |
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Called when an action on the socket times out. The socket is |
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destroyed and any active transaction is failed. |
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=cut |
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sub SocketTimeout { |
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my $Socket = shift; |
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KillSocket($Socket); |
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} |
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=pod |
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=head2 Tick |
=head2 Tick |
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Invoked each timer tick. |
Invoked each timer tick. |
Line 284 Invoked each timer tick.
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Line 335 Invoked each timer tick.
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sub Tick { |
sub Tick { |
my $client; |
my $client; |
ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount); |
ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount); |
Debug(6, "Tick"); |
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Debug(6, " Current connection count: ".$ConnectionCount); |
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foreach $client (keys %ActiveClients) { |
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Debug(7, " Have client: with id: ".$ActiveClients{$client}); |
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} |
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# Is it time to prune connection count: |
# Is it time to prune connection count: |
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Line 302 sub Tick {
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Line 349 sub Tick {
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} else { |
} else { |
$IdleSeconds = 0; # Reset idle count if not idle. |
$IdleSeconds = 0; # Reset idle count if not idle. |
} |
} |
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# |
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# For each inflight transaction, tick down its timeout counter. |
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# |
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foreach $item (keys %ActiveTransactions) { |
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my $Socket = $ActiveTransactions{$item}->getServer(); |
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$Socket->Tick(); |
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} |
# Do we have work in the queue, but no connections to service them? |
# Do we have work in the queue, but no connections to service them? |
# If so, try to make some new connections to get things going again. |
# If so, try to make some new connections to get things going again. |
# |
# |
Line 440 sub ClientWritable {
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Line 493 sub ClientWritable {
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} else { # Partial string sent. |
} else { # Partial string sent. |
$Watcher->data(substr($Data, $result)); |
$Watcher->data(substr($Data, $result)); |
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if($result == 0) { # client hung up on us!! |
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Log("INFO", "lonc pipe client hung up on us!"); |
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$Watcher->cancel; |
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$Socket->shutdown(2); |
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$Socket->close(); |
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} |
} |
} |
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} else { # Error of some sort... |
} else { # Error of some sort... |
Line 520 sub StartClientReply {
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Line 579 sub StartClientReply {
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my $Transaction = shift; |
my $Transaction = shift; |
my $data = shift; |
my $data = shift; |
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my $Client = $Transaction->getClient(); |
my $Client = $Transaction->getClient(); |
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&Debug(8," Reply was: ".$data); |
&Debug(8," Reply was: ".$data); |
Line 556 Parameters:
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Line 616 Parameters:
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sub FailTransaction { |
sub FailTransaction { |
my $transaction = shift; |
my $transaction = shift; |
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Log("WARNING", "Failing transaction ".$transaction->getRequest()); |
Debug(1, "Failing transaction: ".$transaction->getRequest()); |
Debug(1, "Failing transaction: ".$transaction->getRequest()); |
if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it. |
if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it. |
my $client = $transcation->getClient(); |
my $client = $transaction->getClient(); |
Debug(1," Replying con_lost to ".$transaction->getRequest()); |
Debug(1," Replying con_lost to ".$transaction->getRequest()); |
StartClientReply($client, "con_lost\n"); |
StartClientReply($transaction, "con_lost\n"); |
} |
} |
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} |
} |
Line 618 nonzero if we are allowed to create a ne
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Line 679 nonzero if we are allowed to create a ne
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sub KillSocket { |
sub KillSocket { |
my $Socket = shift; |
my $Socket = shift; |
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Log("WARNING", "Shutting down a socket"); |
$Socket->Shutdown(); |
$Socket->Shutdown(); |
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# If the socket came from the active connection set, |
# If the socket came from the active connection set, |
Line 713 sub LondReadable {
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Line 775 sub LondReadable {
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my $State = $Socket->GetState(); # All action depends on the state. |
my $State = $Socket->GetState(); # All action depends on the state. |
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SocketDump(6, $Socket); |
SocketDump(6, $Socket); |
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my $status = $Socket->Readable(); |
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&Debug(2, "Socket->Readable returned: $status"); |
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if($Socket->Readable() != 0) { |
if($status != 0) { |
# bad return from socket read. Currently this means that |
# bad return from socket read. Currently this means that |
# The socket has become disconnected. We fail the transaction. |
# The socket has become disconnected. We fail the transaction. |
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Log("WARNING", |
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"Lond connection lost."); |
if(exists($ActiveTransactions{$Socket})) { |
if(exists($ActiveTransactions{$Socket})) { |
Debug(3,"Lond connection lost failing transaction"); |
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FailTransaction($ActiveTransactions{$Socket}); |
FailTransaction($ActiveTransactions{$Socket}); |
} |
} |
$Watcher->cancel(); |
$Watcher->cancel(); |
Line 869 sub LondWritable {
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Line 935 sub LondWritable {
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# We'll treat this as if the socket got disconnected: |
# We'll treat this as if the socket got disconnected: |
Log("WARNING", "Connection to ".$RemoteHost. |
Log("WARNING", "Connection to ".$RemoteHost. |
" has been disconnected"); |
" has been disconnected"); |
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FailTransaction($ActiveTransactions{$Socket}); |
$Watcher->cancel(); |
$Watcher->cancel(); |
KillSocket($Socket); |
KillSocket($Socket); |
return; |
return; |
Line 979 sub QueueDelayed {
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Line 1046 sub QueueDelayed {
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my $Handle = IO::File->new($reqfile); |
my $Handle = IO::File->new($reqfile); |
my $cmd = <$Handle>; |
my $cmd = <$Handle>; |
chomp $cmd; # There may or may not be a newline... |
chomp $cmd; # There may or may not be a newline... |
$cmd = $cmd."\ny"; # now for sure there's exactly one newline. |
$cmd = $cmd."\n"; # now for sure there's exactly one newline. |
my $Transaction = LondTransaction->new($cmd); |
my $Transaction = LondTransaction->new($cmd); |
$Transaction->SetDeferred($reqfile); |
$Transaction->SetDeferred($reqfile); |
QueueTransaction($Transaction); |
QueueTransaction($Transaction); |
Line 1124 sub QueueTransaction {
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Line 1191 sub QueueTransaction {
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$WorkQueue->enqueue($requestData); |
$WorkQueue->enqueue($requestData); |
if($ConnectionCount < $MaxConnectionCount) { |
if($ConnectionCount < $MaxConnectionCount) { |
Debug(4,"Starting additional lond connection"); |
Debug(4,"Starting additional lond connection"); |
MakeLondConnection(); |
if(MakeLondConnection() == 0) { |
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EmptyQueue(); # Fail transactions, can't make connection. |
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} |
} |
} |
} else { # Can start the request: |
} else { # Can start the request: |
Debug(8,"Can start..."); |
Debug(8,"Can start..."); |
Line 1282 sub SetupLoncListener {
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Line 1351 sub SetupLoncListener {
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fd => $socket); |
fd => $socket); |
} |
} |
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=pod |
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=head2 ChildStatus |
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Child USR1 signal handler to report the most recent status |
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into the status file. |
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=cut |
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sub ChildStatus { |
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my $event = shift; |
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my $watcher = $event->w; |
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Debug(2, "Reporting child status because : ".$watcher->data); |
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my $docdir = $perlvar{'lonDocRoot'}; |
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my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt"); |
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print $fh $$."\t".$RemoteHost."\t".$Status."\t". |
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$RecentLogEntry."\n"; |
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} |
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=pod |
=pod |
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=head2 SignalledToDeath |
=head2 SignalledToDeath |
Line 1290 Called in response to a signal that caus
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Line 1378 Called in response to a signal that caus
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=cut |
=cut |
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=pod |
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sub SignalledToDeath { |
sub SignalledToDeath { |
my ($signal) = @_; |
my $event = shift; |
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my $watcher= $event->w; |
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Debug(2,"Signalled to death! via ".$watcher->data); |
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my ($signal) = $watcher->data; |
chomp($signal); |
chomp($signal); |
Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost " |
Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost " |
."died through "."\"$signal\""); |
."died through "."\"$signal\""); |
LogPerm("F:lonc: $$ on $RemoteHost signalled to death: " |
LogPerm("F:lonc: $$ on $RemoteHost signalled to death: " |
."\"$signal\""); |
."\"$signal\""); |
die("Signal abnormal end"); |
exit 0; |
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} |
} |
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=head2 ToggleDebug |
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This sub toggles trace debugging on and off. |
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=cut |
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sub ToggleDebug { |
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my $Current = $DebugLevel; |
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$DebugLevel = $NextDebugLevel; |
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$NextDebugLevel = $Current; |
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Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel"); |
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} |
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=head2 ChildProcess |
=head2 ChildProcess |
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This sub implements a child process for a single lonc daemon. |
This sub implements a child process for a single lonc daemon. |
Line 1311 This sub implements a child process for
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Line 1418 This sub implements a child process for
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sub ChildProcess { |
sub ChildProcess { |
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# For now turn off signals. |
# |
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# Signals must be handled by the Event framework... |
$SIG{QUIT} = \&SignalledToDeath; |
# |
$SIG{HUP} = IGNORE; |
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$SIG{USR1} = IGNORE; |
Event->signal(signal => "QUIT", |
$SIG{INT} = IGNORE; |
cb => \&SignalledToDeath, |
$SIG{CHLD} = IGNORE; |
data => "QUIT"); |
$SIG{__DIE__} = \&SignalledToDeath; |
Event->signal(signal => "HUP", |
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cb => \&ChildStatus, |
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data => "HUP"); |
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Event->signal(signal => "USR1", |
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cb => \&ChildStatus, |
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data => "USR1"); |
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Event->signal(signal => "INT", |
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cb => \&ToggleDebug, |
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data => "INT"); |
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SetupTimer(); |
SetupTimer(); |
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Line 1330 sub ChildProcess {
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Line 1445 sub ChildProcess {
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# Setup the initial server connection: |
# Setup the initial server connection: |
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# &MakeLondConnection(); // let first work requirest do it. |
# &MakeLondConnection(); // let first work requirest do it. |
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Debug(9,"Entering event loop"); |
Debug(9,"Entering event loop"); |
Line 1343 sub ChildProcess {
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Line 1458 sub ChildProcess {
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# Create a new child for host passed in: |
# Create a new child for host passed in: |
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sub CreateChild { |
sub CreateChild { |
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my $sigset = POSIX::SigSet->new(SIGINT); |
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sigprocmask(SIG_BLOCK, $sigset); |
my $host = shift; |
my $host = shift; |
$RemoteHost = $host; |
$RemoteHost = $host; |
Log("CRITICAL", "Forking server for ".$host); |
Log("CRITICAL", "Forking server for ".$host); |
$pid = fork; |
$pid = fork; |
if($pid) { # Parent |
if($pid) { # Parent |
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$RemoteHost = "Parent"; |
$ChildHash{$pid} = $RemoteHost; |
$ChildHash{$pid} = $RemoteHost; |
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sigprocmask(SIG_UNBLOCK, $sigset); |
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} else { # child. |
} else { # child. |
ShowStatus("Connected to ".$RemoteHost); |
ShowStatus("Connected to ".$RemoteHost); |
ChildProcess; |
$SIG{INT} = DEFAULT; |
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sigprocmask(SIG_UNBLOCK, $sigset); |
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ChildProcess; # Does not return. |
} |
} |
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} |
} |
Line 1391 open (PIDSAVE, ">$execdir/logs/lonc.pid"
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Line 1513 open (PIDSAVE, ">$execdir/logs/lonc.pid"
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print PIDSAVE "$$\n"; |
print PIDSAVE "$$\n"; |
close(PIDSAVE); |
close(PIDSAVE); |
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if (POSIX::setsid() < 0) { |
if (POSIX::setsid() < 0) { |
print "Could not create new session\n"; |
print "Could not create new session\n"; |
exit -1; |
exit -1; |
Line 1407 while (! $HostIterator->end()) {
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Line 1531 while (! $HostIterator->end()) {
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CreateChild($hostentryref->[0]); |
CreateChild($hostentryref->[0]); |
$HostIterator->next(); |
$HostIterator->next(); |
} |
} |
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$RemoteHost = "Parent Server"; |
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# Maintain the population: |
# Maintain the population: |
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Line 1415 ShowStatus("Parent keeping the flock");
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Line 1540 ShowStatus("Parent keeping the flock");
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# |
# |
# Set up parent signals: |
# Set up parent signals: |
# |
# |
$SIG{INT} = &KillThemAll; |
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$SIG{TERM} = &KillThemAll; |
$SIG{INT} = \&Terminate; |
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$SIG{TERM} = \&Terminate; |
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$SIG{HUP} = \&Restart; |
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$SIG{USR1} = \&CheckKids; |
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while(1) { |
while(1) { |
$deadchild = wait(); |
$deadchild = wait(); |
Line 1429 while(1) {
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Line 1557 while(1) {
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CreateChild($deadhost); |
CreateChild($deadhost); |
} |
} |
} |
} |
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=pod |
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=head1 CheckKids |
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Since kids do not die as easily in this implementation |
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as the previous one, there is no need to restart the |
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dead ones (all dead kids get restarted when they die!!) |
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The only thing this function does is to pass USR1 to the |
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kids so that they report their status. |
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=cut |
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sub CheckKids { |
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Debug(2, "Checking status of children"); |
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my $docdir = $perlvar{'lonDocRoot'}; |
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my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt"); |
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my $now=time; |
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my $local=localtime($now); |
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print $fh "LONC status $local - parent $$ \n\n"; |
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foreach $pid (keys %ChildHash) { |
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Debug(2, "Sending USR1 -> $pid"); |
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kill 'USR1' => $pid; # Tell Child to report status. |
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sleep 1; # Wait so file doesn't intermix. |
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} |
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} |
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=pod |
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=head1 Restart |
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Signal handler for HUP... all children are killed and |
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we self restart. This is an el-cheapo way to re read |
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the config file. |
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=cut |
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sub Restart { |
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KillThemAll; # First kill all the children. |
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Log("CRITICAL", "Restarting"); |
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my $execdir = $perlvar{'lonDaemons'}; |
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unlink("$execdir/logs/lonc.pid"); |
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exec("$execdir/lonc"); |
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} |
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=pod |
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=head1 KillThemAll |
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Signal handler that kills all children by sending them a |
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SIGHUP. Responds to sigint and sigterm. |
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=cut |
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sub KillThemAll { |
sub KillThemAll { |
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Debug(2, "Kill them all!!"); |
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local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die. |
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foreach $pid (keys %ChildHash) { |
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my $serving = $ChildHash{$pid}; |
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Debug(2, "Killing lonc for $serving pid = $pid"); |
|
ShowStatus("Killing lonc for $serving pid = $pid"); |
|
Log("CRITICAL", "Killing lonc for $serving pid = $pid"); |
|
kill 'QUIT' => $pid; |
|
delete($ChildHash{$pid}); |
|
} |
|
my $execdir = $perlvar{'lonDaemons'}; |
|
unlink("$execdir/logs/lonc.pid"); |
|
|
} |
} |
|
|
|
=pod |
|
|
|
=head1 Terminate |
|
|
|
Terminate the system. |
|
|
|
=cut |
|
|
|
sub Terminate { |
|
KillThemAll; |
|
Log("CRITICAL","Master process exiting"); |
|
exit 0; |
|
|
|
} |
|
=pod |
|
|
=head1 Theory |
=head1 Theory |
|
|
The event class is used to build this as a single process with an |
The event class is used to build this as a single process with an |