--- loncom/loncnew 2003/06/03 01:59:39 1.7
+++ loncom/loncnew 2006/08/25 21:12:19 1.76
@@ -2,13 +2,12 @@
# The LearningOnline Network with CAPA
# lonc maintains the connections to remote computers
#
-# $Id: loncnew,v 1.7 2003/06/03 01:59:39 foxr Exp $
+# $Id: loncnew,v 1.76 2006/08/25 21:12:19 albertel 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
+## 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.
@@ -27,7 +26,7 @@
# 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.
# Development iterations:
# - Setup basic event loop. (done)
@@ -36,28 +35,23 @@
# - Add ability to create/negotiate lond connections (done).
# - Add general logic for dispatching requests and timeouts. (done).
# - Add support for the lonc/lond requests. (done).
-# - Add logging/status monitoring.
-# - Add Signal handling - HUP restarts. USR1 status report.
+# - Add logging/status monitoring. (done)
+# - Add Signal handling - HUP restarts. USR1 status report. (done)
# - Add Configuration file I/O (done).
-# - Add Pending request processing on startup.
-# - Add management/status request interface.
-# - Add deferred request capability.
-#
-
-# Change log:
-# $Log: loncnew,v $
-# Revision 1.7 2003/06/03 01:59:39 foxr
-# complete coding to support deferred transactions.
-#
+# - Add management/status request interface. (done)
+# - Add deferred request capability. (done)
+# - Detect transmission timeouts. (done)
#
+use strict;
use lib "/home/httpd/lib/perl/";
-use lib "/home/foxr/newloncapa/types";
use Event qw(:DEFAULT );
use POSIX qw(:signal_h);
+use POSIX;
use IO::Socket;
use IO::Socket::INET;
use IO::Socket::UNIX;
+use IO::File;
use IO::Handle;
use Socket;
use Crypt::IDEA;
@@ -67,18 +61,7 @@ use LONCAPA::LondConnection;
use LONCAPA::LondTransaction;
use LONCAPA::Configuration;
use LONCAPA::HashIterator;
-
-print "Loncnew starting\n";
-
-#
-# Disable all signals we might receive from outside for now.
-#
-$SIG{QUIT} = IGNORE;
-$SIG{HUP} = IGNORE;
-$SIG{USR1} = IGNORE;
-$SIG{INT} = IGNORE;
-$SIG{CHLD} = IGNORE;
-$SIG{__DIE__} = IGNORE;
+use Fcntl qw(:flock);
# Read the httpd configuration file to get perl variables
@@ -91,35 +74,143 @@ my %perlvar = %{$perlvarref};
# parent and shared variables.
my %ChildHash; # by pid -> host.
+my %HostToPid; # By host -> pid.
+my %HostHash; # by loncapaname -> IP.
+my %listening_to; # Socket->host table for who the parent
+ # is listening to.
+my %parent_dispatchers; # host-> listener watcher events.
+my %parent_handlers; # Parent signal handlers...
-my $MaxConnectionCount = 5; # Will get from config later.
+my $MaxConnectionCount = 10; # Will get from config later.
my $ClientConnection = 0; # Uniquifier for client events.
-my $DebugLevel = 5;
-my $IdleTimeout= 3600; # Wait an hour before pruning connections.
+my $DebugLevel = 0;
+my $NextDebugLevel= 2; # So Sigint can toggle this.
+my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.
+
+my $LogTransactions = 0; # When True, all transactions/replies get logged.
+my $executable = $0; # Get the full path to me.
#
# The variables below are only used by the child processes.
#
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 %ActiveConnections; # Connections to the remote lond.
my %ActiveTransactions; # LondTransactions in flight.
my %ActiveClients; # Serial numbers of active clients by socket.
my $WorkQueue = Queue->new(); # Queue of pending transactions.
-# my $ClientQueue = Queue->new(); # Queue of clients causing xactinos.
my $ConnectionCount = 0;
my $IdleSeconds = 0; # Number of seconds idle.
+my $Status = ""; # Current status string.
+my $RecentLogEntry = "";
+my $ConnectionRetries=5; # Number of connection retries allowed.
+my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
+my $LondVersion = "unknown"; # Version of lond we talk with.
+my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
+my $LondConnecting = 0; # True when a connection is being built.
+
+
+
+my $DieWhenIdle = 1; # When true children die when trimmed -> 0.
+my $I_am_child = 0; # True if this is the child process.
#
-# This disconnected socket makes posible a bit more regular
-# code when processing delayed requests:
-#
-my $NullSocket = IO::Socket->new();
+# The hash below gives the HTML format for log messages
+# given a severity.
+#
+my %LogFormats;
+
+$LogFormats{"CRITICAL"} = "CRITICAL: %s";
+$LogFormats{"SUCCESS"} = "SUCCESS: %s";
+$LogFormats{"INFO"} = "INFO: %s";
+$LogFormats{"WARNING"} = "WARNING: %s";
+$LogFormats{"DEFAULT"} = " %s ";
+
+# UpdateStatus;
+# Update the idle status display to show how many connections
+# are left, retries and other stuff.
#
+sub UpdateStatus {
+ if ($ConnectionRetriesLeft > 0) {
+ ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
+ ." Retries remaining: ".$ConnectionRetriesLeft
+ ." ($KeyMode)");
+ } else {
+ ShowStatus(GetServerHost()." >> DEAD <<");
+ }
+}
+
+
+=pod
+
+=head2 LogPerm
+
+Makes an entry into the permanent log file.
+
+=cut
+
+sub LogPerm {
+ my $message=shift;
+ my $execdir=$perlvar{'lonDaemons'};
+ my $now=time;
+ my $local=localtime($now);
+ my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
+ print $fh "$now:$message:$local\n";
+}
+
+=pod
+
+=head2 Log
+
+Logs a message to the log file.
+Parameters:
+
+=item severity
+
+One of CRITICAL, WARNING, INFO, SUCCESS used to select the
+format string used to format the message. if the severity is
+not a defined severity the Default format string is used.
+
+=item message
+
+The base message. In addtion to the format string, the message
+will be appended to a string containing the name of our remote
+host and the time will be formatted into the message.
+
+=cut
+
+sub Log {
+
+ my ($severity, $message) = @_;
+
+ if(!$LogFormats{$severity}) {
+ $severity = "DEFAULT";
+ }
+
+ my $format = $LogFormats{$severity};
+
+ # Put the window dressing in in front of the message format:
+
+ my $now = time;
+ my $local = localtime($now);
+ my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
+ $finalformat = $finalformat.$format."\n";
+
+ # open the file and put the result.
+
+ my $execdir = $perlvar{'lonDaemons'};
+ my $fh = IO::File->new(">>$execdir/logs/lonc.log");
+ my $msg = sprintf($finalformat, $message);
+ $RecentLogEntry = $msg;
+ print $fh $msg;
+
+
+}
+
=pod
@@ -130,14 +221,16 @@ Returns the name of the host that a sock
=cut
sub GetPeername {
- my $connection = shift;
- my $AdrFamily = shift;
+
+
+ my ($connection, $AdrFamily) = @_;
+
my $peer = $connection->peername();
my $peerport;
my $peerip;
if($AdrFamily == AF_INET) {
($peerport, $peerip) = sockaddr_in($peer);
- my $peername = gethostbyaddr($iaddr, $AdrFamily);
+ my $peername = gethostbyaddr($peerip, $AdrFamily);
return $peername;
} elsif ($AdrFamily == AF_UNIX) {
my $peerfile;
@@ -145,7 +238,6 @@ sub GetPeername {
return $peerfile;
}
}
-#----------------------------- Timer management ------------------------
=pod
=head2 Debug
@@ -155,18 +247,20 @@ Invoked to issue a debug message.
=cut
sub Debug {
- my $level = shift;
- my $message = shift;
+
+ my ($level, $message) = @_;
+
if ($level <= $DebugLevel) {
- print $message." host = ".$RemoteHost."\n";
+ Log("INFO", "-Debug- $message host = $RemoteHost");
}
}
sub SocketDump {
- my $level = shift;
- my $socket= shift;
+
+ my ($level, $socket) = @_;
+
if($level <= $DebugLevel) {
- $socket->Dump();
+ $socket->Dump(-1); # Ensure it will get dumped.
}
}
@@ -175,15 +269,87 @@ sub SocketDump {
=head2 ShowStatus
Place some text as our pid status.
+ and as what we return in a SIGUSR1
=cut
+
sub ShowStatus {
- my $status = shift;
- $0 = "lonc: ".$status;
+ my $state = shift;
+ my $now = time;
+ my $local = localtime($now);
+ $Status = $local.": ".$state;
+ $0='lonc: '.$state.' '.$local;
}
=pod
+=head2 SocketTimeout
+
+ Called when an action on the socket times out. The socket is
+ destroyed and any active transaction is failed.
+
+
+=cut
+
+sub SocketTimeout {
+ my $Socket = shift;
+ Log("WARNING", "A socket timeout was detected");
+ Debug(5, " SocketTimeout called: ");
+ $Socket->Dump(0);
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ }
+ KillSocket($Socket); # A transaction timeout also counts as
+ # a connection failure:
+ $ConnectionRetriesLeft--;
+ if($ConnectionRetriesLeft <= 0) {
+ Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
+ $LondConnecting = 0;
+ }
+
+}
+#
+# This function should be called by the child in all cases where it must
+# exit. If the child process is running with the DieWhenIdle turned on
+# it must create a lock file for the AF_UNIX socket in order to prevent
+# connection requests from lonnet in the time between process exit
+# and the parent picking up the listen again.
+# Parameters:
+# exit_code - Exit status value, however see the next parameter.
+# message - If this optional parameter is supplied, the exit
+# is via a die with this message.
+#
+sub child_exit {
+ my ($exit_code, $message) = @_;
+
+ # Regardless of how we exit, we may need to do the lock thing:
+
+ if($DieWhenIdle) {
+ #
+ # Create a lock file since there will be a time window
+ # between our exit and the parent's picking up the listen
+ # during which no listens will be done on the
+ # lonnet client socket.
+ #
+ my $lock_file = GetLoncSocketPath().".lock";
+ open(LOCK,">$lock_file");
+ print LOCK "Contents not important";
+ close(LOCK);
+
+ exit(0);
+ }
+ # Now figure out how we exit:
+
+ if($message) {
+ die $message;
+ } else {
+ exit($exit_code);
+ }
+}
+#----------------------------- Timer management ------------------------
+
+=pod
+
=head2 Tick
Invoked each timer tick.
@@ -192,13 +358,12 @@ Invoked each timer tick.
sub Tick {
+ my ($Event) = @_;
+ my $clock_watcher = $Event->w;
+
my $client;
- ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);
- Debug(6, "Tick");
- Debug(6, " Current connection count: ".$ConnectionCount);
- foreach $client (keys %ActiveClients) {
- Debug(7, " Have client: with id: ".$ActiveClients{$client});
- }
+ UpdateStatus();
+
# Is it time to prune connection count:
@@ -206,27 +371,59 @@ sub Tick {
($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
$IdleSeconds++;
if($IdleSeconds > $IdleTimeout) { # Prune a connection...
- $Socket = $IdleConnections->pop();
+ my $Socket = $IdleConnections->pop();
KillSocket($Socket);
+ $IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
+ UpdateStatus();
+ if(($ConnectionCount == 0) && $DieWhenIdle) {
+ &child_exit(0);
+
+ }
}
} else {
$IdleSeconds = 0; # Reset idle count if not idle.
}
+ #
+ # For each inflight transaction, tick down its timeout counter.
+ #
+ foreach my $item (keys %ActiveConnections) {
+ my $State = $ActiveConnections{$item}->data->GetState();
+ if ($State ne 'Idle') {
+ Debug(5,"Ticking Socket $State $item");
+ $ActiveConnections{$item}->data->Tick();
+ }
+ }
# 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.
#
-
+ # Note this code is dead now...
+ #
my $Requests = $WorkQueue->Count();
- if (($ConnectionCount == 0) && ($Requests > 0)) {
- my $Connections = ($Requests <= $MaxConnectionCount) ?
- $Requests : $MaxConnectionCount;
- Debug(1,"Work but no connections, starting ".$Connections." of them");
- for ($i =0; $i < $Connections; $i++) {
- MakeLondConnection();
+ if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
+ if ($ConnectionRetriesLeft > 0) {
+ Debug(5,"Work but no connections, Make a new one");
+ my $success;
+ $success = &MakeLondConnection;
+ if($success == 0) { # All connections failed:
+ Debug(5,"Work in queue failed to make any connectiouns\n");
+ EmptyQueue(); # Fail pending transactions with con_lost.
+ CloseAllLondConnections(); # Should all be closed but....
+ }
+ } else {
+ $LondConnecting = 0;
+ ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
+ Debug(5,"Work in queue, but gave up on connections..flushing\n");
+ EmptyQueue(); # Connections can't be established.
+ CloseAllLondConnections(); # Should all already be closed but...
}
}
+ if ($ConnectionCount == 0) {
+ $KeyMode = "";
+ $clock_watcher->cancel();
+ }
+ &UpdateStatus();
}
=pod
@@ -247,7 +444,7 @@ Trigger disconnections of idle sockets.
sub SetupTimer {
Debug(6, "SetupTimer");
- Event->timer(interval => 1, debug => 1, cb => \&Tick );
+ Event->timer(interval => 1, cb => \&Tick );
}
=pod
@@ -267,20 +464,22 @@ long enough, it will be shut down and re
sub ServerToIdle {
my $Socket = shift; # Get the socket.
+ $KeyMode = $Socket->{AuthenticationMode};
delete($ActiveTransactions{$Socket}); # Server has no transaction
- &Debug(6, "Server to idle");
+ &Debug(5, "Server to idle");
# If there's work to do, start the transaction:
- $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
- unless($reqdata eq undef) {
- Debug(9, "Queue gave request data: ".$reqdata->getRequest());
+ my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
+ if ($reqdata ne undef) {
+ Debug(5, "Queue gave request data: ".$reqdata->getRequest());
&StartRequest($Socket, $reqdata);
+
} else {
# There's no work waiting, so push the server to idle list.
- &Debug(8, "No new work requests, server connection going idle");
+ &Debug(5, "No new work requests, server connection going idle");
$IdleConnections->push($Socket);
}
}
@@ -326,7 +525,7 @@ sub ClientWritable {
# request.
&Debug(9,"Send result is ".$result." Defined: ".defined($result));
- if(defined($result)) {
+ if($result ne undef) {
&Debug(9, "send result was defined");
if($result == length($Data)) { # Entire string sent.
&Debug(9, "ClientWritable data all written");
@@ -344,6 +543,12 @@ sub ClientWritable {
} else { # Partial string sent.
$Watcher->data(substr($Data, $result));
+ if($result == 0) { # client hung up on us!!
+ # Log("INFO", "lonc pipe client hung up on us!");
+ $Watcher->cancel;
+ $Socket->shutdown(2);
+ $Socket->close();
+ }
}
} else { # Error of some sort...
@@ -391,18 +596,25 @@ The transaction that is being completed.
=cut
sub CompleteTransaction {
- &Debug(6,"Complete transaction");
- my $Socket = shift;
- my $Transaction = shift;
+ &Debug(5,"Complete transaction");
+
+ my ($Socket, $Transaction) = @_;
if (!$Transaction->isDeferred()) { # Normal transaction
my $data = $Socket->GetReply(); # Data to send.
+ if($LogTransactions) {
+ Log("SUCCESS", "Reply from lond: '$data'");
+ }
StartClientReply($Transaction, $data);
} else { # Delete deferred transaction file.
+ Log("SUCCESS", "A delayed transaction was completed");
+ LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
unlink $Transaction->getFile();
}
}
+
=pod
+
=head1 StartClientReply
Initiates a reply to a client where the reply data is a parameter.
@@ -418,16 +630,16 @@ sub CompleteTransaction {
The data to send to apached client.
=cut
+
sub StartClientReply {
- my $Transaction = shift;
- my $data = shift;
+
+ my ($Transaction, $data) = @_;
my $Client = $Transaction->getClient();
&Debug(8," Reply was: ".$data);
my $Serial = $ActiveClients{$Client};
my $desc = sprintf("Connection to lonc client %d",
-
$Serial);
Event->io(fd => $Client,
poll => "w",
@@ -435,7 +647,9 @@ sub StartClientReply {
cb => \&ClientWritable,
data => $data);
}
+
=pod
+
=head2 FailTransaction
Finishes a transaction with failure because the associated lond socket
@@ -445,8 +659,7 @@ sub StartClientReply {
- The transaction is 'live' in which case we initiate the sending
of "con_lost" to the client.
-Deleting the transaction means killing it from the
-%ActiveTransactions hash.
+Deleting the transaction means killing it from the %ActiveTransactions hash.
Parameters:
@@ -454,36 +667,63 @@ Parameters:
The LondTransaction we are failing.
+
=cut
sub FailTransaction {
my $transaction = shift;
- my $Lond = $transaction->getServer();
- if (!$client->isDeferred()) { # If the transaction is deferred we'll get to it.
- my $client = $transcation->getClient();
- StartClientReply($client, "con_lost");
+
+ # If the socket is dead, that's already logged.
+
+ if ($ConnectionRetriesLeft > 0) {
+ Log("WARNING", "Failing transaction "
+ .$transaction->getLoggableRequest());
+ }
+ Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
+ if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
+ my $client = $transaction->getClient();
+ Debug(1," Replying con_lost to ".$transaction->getRequest());
+ StartClientReply($transaction, "con_lost\n");
}
-# not needed, done elsewhere if active.
-# delete $ActiveTransactions{$Lond};
}
=pod
+
=head1 EmptyQueue
Fails all items in the work queue with con_lost.
Note that each item in the work queue is a transaction.
=cut
+
sub EmptyQueue {
+ $ConnectionRetriesLeft--; # Counts as connection failure too.
while($WorkQueue->Count()) {
- my $request = $Workqueue->dequeue(); # This is a transaction
+ my $request = $WorkQueue->dequeue(); # This is a transaction
FailTransaction($request);
}
}
=pod
+=head2 CloseAllLondConnections
+
+Close all connections open on lond prior to exit e.g.
+
+=cut
+
+sub CloseAllLondConnections {
+ foreach my $Socket (keys %ActiveConnections) {
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ }
+ KillSocket($Socket);
+ }
+}
+
+=pod
+
=head2 KillSocket
Destroys a socket. This function can be called either when a socket
@@ -502,11 +742,14 @@ Parameters:
nonzero if we are allowed to create a new connection.
-
=cut
+
sub KillSocket {
my $Socket = shift;
+ Log("WARNING", "Shutting down a socket");
+ $Socket->Shutdown();
+
# If the socket came from the active connection set,
# delete its transaction... note that FailTransaction should
# already have been called!!!
@@ -518,14 +761,15 @@ sub KillSocket {
}
if(exists($ActiveConnections{$Socket})) {
delete($ActiveConnections{$Socket});
+ $ConnectionCount--;
+ if ($ConnectionCount < 0) { $ConnectionCount = 0; }
}
- $ConnectionCount--;
-
# If the connection count has gone to zero and there is work in the
# work queue, the work all gets failed with con_lost.
#
if($ConnectionCount == 0) {
- EmptyQueue;
+ EmptyQueue();
+ CloseAllLondConnections; # Should all already be closed but...
}
}
@@ -551,6 +795,17 @@ The connection must echo the challenge b
The challenge has been replied to. The we are receiveing the
'ok' from the partner.
+=head3 State=ReadingVersionString
+
+We have requested the lond version and are reading the
+version back. Upon completion, we'll store the version away
+for future use(?).
+
+=head3 State=HostSet
+
+We have selected the domain name of our peer (multhomed hosts)
+and are getting the reply (presumably ok) back.
+
=head3 State=RequestingKey
The ok has been received and we need to send the request for
@@ -588,27 +843,39 @@ transaction is in progress, the socket a
=cut
sub LondReadable {
+
my $Event = shift;
my $Watcher = $Event->w;
my $Socket = $Watcher->data;
my $client = undef;
+ &Debug(6,"LondReadable called state = ".$Socket->GetState());
+
my $State = $Socket->GetState(); # All action depends on the state.
- &Debug(6,"LondReadable called state = ".$State);
SocketDump(6, $Socket);
+ my $status = $Socket->Readable();
- if($Socket->Readable() != 0) {
- # bad return from socket read. Currently this means that
+ &Debug(2, "Socket->Readable returned: $status");
+
+ if($status != 0) {
+ # bad return from socket read. Currently this means that
# The socket has become disconnected. We fail the transaction.
+ Log("WARNING",
+ "Lond connection lost.");
if(exists($ActiveTransactions{$Socket})) {
- Debug(3,"Lond connection lost failing transaction");
FailTransaction($ActiveTransactions{$Socket});
+ } else {
+ # Socket is connecting and failed... need to mark
+ # no longer connecting.
+
+ $LondConnecting = 0;
}
$Watcher->cancel();
KillSocket($Socket);
+ $ConnectionRetriesLeft--; # Counts as connection failure
return;
}
SocketDump(6,$Socket);
@@ -616,45 +883,79 @@ sub LondReadable {
$State = $Socket->GetState(); # Update in case of transition.
&Debug(6, "After read, state is ".$State);
- if($State eq "Initialized") {
+ if($State eq "Initialized") {
} elsif ($State eq "ChallengeReceived") {
# The challenge must be echoed back; The state machine
# in the connection takes care of setting that up. Just
# need to transition to writable:
-
- $Watcher->poll("w");
+
$Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
} elsif ($State eq "ChallengeReplied") {
+ } elsif ($State eq "RequestingVersion") {
+ # Need to ask for the version... that is writiability:
+
+ $Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
+
+ } elsif ($State eq "ReadingVersionString") {
+ # Read the rest of the version string...
+ } elsif ($State eq "SetHost") {
+ # Need to request the actual domain get set...
+
+ $Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
+ } elsif ($State eq "HostSet") {
+ # Reading the 'ok' from the peer.
} elsif ($State eq "RequestingKey") {
# The ok was received. Now we need to request the key
# That requires us to be writable:
- $Watcher->poll("w");
$Watcher->cb(\&LondWritable);
+ $Watcher->poll("w");
} elsif ($State eq "ReceivingKey") {
} elsif ($State eq "Idle") {
+
+ # This is as good a spot as any to get the peer version
+ # string:
+
+ if($LondVersion eq "unknown") {
+ $LondVersion = $Socket->PeerVersion();
+ Log("INFO", "Connected to lond version: $LondVersion");
+ }
# If necessary, complete a transaction and then go into the
# idle queue.
+ # Note that a trasition to idle indicates a live lond
+ # on the other end so reset the connection retries.
+ #
+ $ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
+ $Watcher->cancel();
if(exists($ActiveTransactions{$Socket})) {
- Debug(8,"Completing transaction!!");
+ Debug(5,"Completing transaction!!");
CompleteTransaction($Socket,
$ActiveTransactions{$Socket});
+ } else {
+ Log("SUCCESS", "Connection ".$ConnectionCount." to "
+ .$RemoteHost." now ready for action");
}
- $Watcher->cancel();
ServerToIdle($Socket); # Next work unit or idle.
+
+ #
+ $LondConnecting = 0; # Best spot I can think of for this.
+ #
} elsif ($State eq "SendingRequest") {
# We need to be writable for this and probably don't belong
# here inthe first place.
- Deubg(6, "SendingRequest state encountered in readable");
+ Debug(6, "SendingRequest state encountered in readable");
$Watcher->poll("w");
$Watcher->cb(\&LondWritable);
@@ -662,7 +963,7 @@ sub LondReadable {
} else {
- # Invalid state.
+ # Invalid state.
Debug(4, "Invalid state in LondReadable");
}
}
@@ -731,102 +1032,116 @@ is the socket on which to return a reply
sub LondWritable {
my $Event = shift;
my $Watcher = $Event->w;
- my @data = $Watcher->data;
- Debug(6,"LondWritable State = ".$State." data has ".@data." elts.\n");
+ my $Socket = $Watcher->data;
+ my $State = $Socket->GetState();
- my $Socket = $data; # I know there's at least a socket.
+ Debug(6,"LondWritable State = ".$State."\n");
+
# Figure out what to do depending on the state of the socket:
- my $State = $Socket->GetState();
SocketDump(6,$Socket);
- if ($State eq "Connected") {
+ # If the socket is writable, we must always write.
+ # Only by writing will we undergo state transitions.
+ # Old logic wrote in state specific code below, however
+ # That forces us at least through another invocation of
+ # this function after writability is possible again.
+ # This logic also factors out common code for handling
+ # write failures... in all cases, write failures
+ # Kill the socket.
+ # This logic makes the branches of the >big< if below
+ # so that the writing states are actually NO-OPs.
+
+ if ($Socket->Writable() != 0) {
+ # The write resulted in an error.
+ # We'll treat this as if the socket got disconnected:
+ Log("WARNING", "Connection to ".$RemoteHost.
+ " has been disconnected");
+ if(exists($ActiveTransactions{$Socket})) {
+ FailTransaction($ActiveTransactions{$Socket});
+ } else {
+ # In the process of conneting, so need to turn that off.
+
+ $LondConnecting = 0;
+ }
+ $Watcher->cancel();
+ KillSocket($Socket);
+ return;
+ }
- if ($Socket->Writable() != 0) {
- # The write resulted in an error.
- # We'll treat this as if the socket got disconnected:
- $Watcher->cancel();
- KillSocket($Socket);
- return;
- }
- # "init" is being sent...
-
+ if ($State eq "Connected") {
+
+ # "init" is being sent...
+
} elsif ($State eq "Initialized") {
# Now that init was sent, we switch
# to watching for readability:
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
-
+ $Watcher->poll("r");
+
} elsif ($State eq "ChallengeReceived") {
# We received the challenge, now we
# are echoing it back. This is a no-op,
# we're waiting for the state to change
- if($Socket->Writable() != 0) {
-
- $Watcher->cancel();
- KillSocket($Socket);
- return;
- }
-
} elsif ($State eq "ChallengeReplied") {
# The echo was sent back, so we switch
# to watching readability.
+ $Watcher->cb(\&LondReadable);
$Watcher->poll("r");
+ } elsif ($State eq "RequestingVersion") {
+ # Sending the peer a version request...
+
+ } elsif ($State eq "ReadingVersionString") {
+ # Transition to read since we have sent the
+ # version command and now just need to read the
+ # version string from the peer:
+
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
+
+ } elsif ($State eq "SetHost") {
+ # Setting the remote domain...
+
+ } elsif ($State eq "HostSet") {
+ # Back to readable to get the ok.
+
+ $Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
+
} elsif ($State eq "RequestingKey") {
# At this time we're requesting the key.
# again, this is essentially a no-op.
- # we'll write the next chunk until the
- # state changes.
- if($Socket->Writable() != 0) {
- # Write resulted in an error.
-
- $Watcher->cancel();
- KillSocket($Socket);
- return;
-
- }
} elsif ($State eq "ReceivingKey") {
# Now we need to wait for the key
# to come back from the peer:
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
} elsif ($State eq "SendingRequest") {
+
# At this time we are sending a request to the
# peer... write the next chunk:
- if($Socket->Writable() != 0) {
-
- if(exists($ActiveTransactions{$Socket})) {
- Debug(3, "Lond connection lost, failing transactions");
- FailTransaction($ActiveTransactions{$Socket});
- }
- $Watcher->cancel();
- KillSocket($Socket);
- return;
-
- }
} elsif ($State eq "ReceivingReply") {
# The send has completed. Wait for the
# data to come in for a reply.
Debug(8,"Writable sent request/receiving reply");
- $Watcher->poll("r");
$Watcher->cb(\&LondReadable);
+ $Watcher->poll("r");
} else {
# Control only passes here on an error:
@@ -841,19 +1156,36 @@ sub LondWritable {
=pod
=cut
+
sub QueueDelayed {
+ Debug(3,"QueueDelayed called");
+
my $path = "$perlvar{'lonSockDir'}/delayed";
+
+ Debug(4, "Delayed path: ".$path);
opendir(DIRHANDLE, $path);
- @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
+
+ my @all_host_ids;
+ my $host_iterator = &LondConnection::GetHostIterator();
+ while (!$host_iterator->end()) {
+ my ($host_id,$host_name) = @{$host_iterator->get()}[0,3];
+ if ($host_name eq $RemoteHost) {
+ push(@all_host_ids, $host_id);
+ }
+ $host_iterator->next();
+ }
+ my $host_id_re = '(?:'.join('|',@all_host_ids).')';
+ my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
closedir(DIRHANDLE);
- my $dfname;
- my $reqfile
- foreach $reqfile (sort @alldelayed) {
- $reqfile = $path/$reqfile;
+ foreach my $dfname (sort(@alldelayed)) {
+ my $reqfile = "$path/$dfname";
+ my ($host_id) = ($dfname =~ /\.([^.]*)$/);
+ Debug(4, "queueing ".$reqfile." for $host_id");
my $Handle = IO::File->new($reqfile);
my $cmd = <$Handle>;
- chomp($cmd);
- my $Transaction = LondTransaction->new($cmd);
+ chomp $cmd; # There may or may not be a newline...
+ $cmd = $cmd."\n"; # now for sure there's exactly one newline.
+ my $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
$Transaction->SetDeferred($reqfile);
QueueTransaction($Transaction);
}
@@ -879,33 +1211,44 @@ sub MakeLondConnection {
my $Connection = LondConnection->new(&GetServerHost(),
&GetServerPort());
- if($Connection == undef) { # Needs to be more robust later.
- Debug(0,"Failed to make a connection with lond.");
+ if($Connection eq undef) { # Needs to be more robust later.
+ Log("CRITICAL","Failed to make a connection with lond.");
+ $ConnectionRetriesLeft--;
+ return 0; # Failure.
} else {
+
# The connection needs to have writability
# monitored in order to send the init sequence
# that starts the whole authentication/key
# exchange underway.
#
my $Socket = $Connection->GetSocket();
- if($Socket == undef) {
- die "did not get a socket from the connection";
+ if($Socket eq undef) {
+ &child_exit(-1, "did not get a socket from the connection");
} else {
&Debug(9,"MakeLondConnection got socket: ".$Socket);
}
-
- $event = Event->io(fd => $Socket,
+ $Connection->SetTimeoutCallback(\&SocketTimeout);
+
+ my $event = Event->io(fd => $Socket,
poll => 'w',
cb => \&LondWritable,
- data => \$Connection,
+ data => $Connection,
desc => 'Connection to lond server');
$ActiveConnections{$Connection} = $event;
-
+ if ($ConnectionCount == 0) {
+ &SetupTimer; # Need to handle timeouts with connections...
+ }
$ConnectionCount++;
+ Debug(4, "Connection count = ".$ConnectionCount);
if($ConnectionCount == 1) { # First Connection:
QueueDelayed;
}
+ Log("SUCESS", "Created connection ".$ConnectionCount
+ ." to host ".GetServerHost());
+ $LondConnecting = 1; # Connection in progress.
+ return 1; # Return success.
}
}
@@ -936,8 +1279,8 @@ The text of the request to send.
=cut
sub StartRequest {
- my $Lond = shift;
- my $Request = shift; # This is a LondTransaction.
+
+ my ($Lond, $Request) = @_;
Debug(6, "StartRequest: ".$Request->getRequest());
@@ -947,7 +1290,7 @@ sub StartRequest {
$ActiveTransactions{$Lond} = $Request;
$Lond->InitiateTransaction($Request->getRequest());
- $event = Event->io(fd => $Lond->GetSocket(),
+ my $event = Event->io(fd => $Socket,
poll => "w",
cb => \&LondWritable,
data => $Lond,
@@ -986,11 +1329,23 @@ sub QueueTransaction {
my $LondSocket = $IdleConnections->pop();
if(!defined $LondSocket) { # Need to queue request.
- Debug(8,"Must queue...");
+ Debug(5,"Must queue...");
$WorkQueue->enqueue($requestData);
- if($ConnectionCount < $MaxConnectionCount) {
- Debug(4,"Starting additional lond connection");
- MakeLondConnection();
+ Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
+ if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {
+
+ if($ConnectionRetriesLeft > 0) {
+ Debug(5,"Starting additional lond connection");
+ if(&MakeLondConnection() == 0) {
+ EmptyQueue(); # Fail transactions, can't make connection.
+ CloseAllLondConnections; # Should all be closed but...
+ }
+ } else {
+ ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
+ $LondConnecting = 0;
+ EmptyQueue(); # It's worse than that ... he's dead Jim.
+ CloseAllLondConnections; # Should all be closed but..
+ }
}
} else { # Can start the request:
Debug(8,"Can start...");
@@ -1003,7 +1358,6 @@ sub QueueTransaction {
=pod
=head2 ClientRequest
-
Callback that is called when data can be read from the UNIX domain
socket connecting us with an apache server process.
@@ -1022,19 +1376,29 @@ sub ClientRequest {
my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
Debug(8, "rcv: data length = ".length($thisread)
." read =".$thisread);
- unless (defined $rv && length($thisread)) {
+ unless (defined $rv && length($thisread)) {
# Likely eof on socket.
Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
close($socket);
$watcher->cancel();
delete($ActiveClients{$socket});
+ return;
}
Debug(8,"Data: ".$data." this read: ".$thisread);
$data = $data.$thisread; # Append new data.
$watcher->data($data);
- if($data =~ /(.*\n)/) { # Request entirely read.
+ if($data =~ /\n$/) { # Request entirely read.
+ if($data eq "close_connection_exit\n") {
+ Log("CRITICAL",
+ "Request Close Connection ... exiting");
+ CloseAllLondConnections();
+ exit;
+ }
Debug(8, "Complete transaction received: ".$data);
- my $Transaction = new LondTransaction->new($data);
+ if($LogTransactions) {
+ Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
+ }
+ my $Transaction = LondTransaction->new($data);
$Transaction->SetClient($socket);
QueueTransaction($Transaction);
$watcher->cancel(); # Done looking for input data.
@@ -1042,6 +1406,40 @@ sub ClientRequest {
}
+#
+# Accept a connection request for a client (lonc child) and
+# start up an event watcher to keep an eye on input from that
+# Event. This can be called both from NewClient and from
+# ChildProcess if we are started in DieWhenIdle mode.
+# Parameters:
+# $socket - The listener socket.
+# Returns:
+# NONE
+# Side Effects:
+# An event is made to watch the accepted connection.
+# Active clients hash is updated to reflect the new connection.
+# The client connection count is incremented.
+#
+sub accept_client {
+ my ($socket) = @_;
+
+ Debug(8, "Entering accept for lonc UNIX socket\n");
+ my $connection = $socket->accept(); # Accept the client connection.
+ Debug(8,"Connection request accepted from "
+ .GetPeername($connection, AF_UNIX));
+
+
+ my $description = sprintf("Connection to lonc client %d",
+ $ClientConnection);
+ Debug(9, "Creating event named: ".$description);
+ Event->io(cb => \&ClientRequest,
+ poll => 'r',
+ desc => $description,
+ data => "",
+ fd => $connection);
+ $ActiveClients{$connection} = $ClientConnection;
+ $ClientConnection++;
+}
=pod
@@ -1060,21 +1458,8 @@ sub NewClient {
my $event = shift; # Get the event parameters.
my $watcher = $event->w;
my $socket = $watcher->fd; # Get the event' socket.
- my $connection = $socket->accept(); # Accept the client connection.
- Debug(8,"Connection request accepted from "
- .GetPeername($connection, AF_UNIX));
-
- my $description = sprintf("Connection to lonc client %d",
- $ClientConnection);
- Debug(9, "Creating event named: ".$description);
- Event->io(cb => \&ClientRequest,
- poll => 'r',
- desc => $description,
- data => "",
- fd => $connection);
- $ActiveClients{$connection} = $ClientConnection;
- $ClientConnection++;
+ &accept_client($socket);
}
=pod
@@ -1084,10 +1469,20 @@ sub NewClient {
Returns the name of the UNIX socket on which to listen for client
connections.
+=head2 Parameters:
+
+ host (optional) - Name of the host socket to return.. defaults to
+ the return from GetServerHost().
+
=cut
sub GetLoncSocketPath {
- return $UnixSocketDir."/".GetServerHost();
+
+ my $host = GetServerHost(); # Default host.
+ if (@_) {
+ ($host) = @_; # Override if supplied.
+ }
+ return $UnixSocketDir."/".$host;
}
=pod
@@ -1124,22 +1519,136 @@ connection. The event handler establish
(creating a communcations channel), that int turn will establish
another event handler to subess requests.
+=head2 Parameters:
+
+ host (optional) Name of the host to set up a unix socket to.
+
=cut
sub SetupLoncListener {
+ my $host = GetServerHost(); # Default host.
+ if (@_) {
+ ($host) = @_ # Override host with parameter.
+ }
+
my $socket;
- my $SocketName = GetLoncSocketPath();
+ my $SocketName = GetLoncSocketPath($host);
unlink($SocketName);
unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
- Listen => 10,
+ Listen => 250,
Type => SOCK_STREAM)) {
- die "Failed to create a lonc listner socket";
+ if($I_am_child) {
+ &child_exit(-1, "Failed to create a lonc listener socket");
+ } else {
+ die "Failed to create a lonc listner socket";
+ }
+ }
+ return $socket;
+}
+
+#
+# Toggle transaction logging.
+# Implicit inputs:
+# LogTransactions
+# Implicit Outputs:
+# LogTransactions
+sub ToggleTransactionLogging {
+ print STDERR "Toggle transaction logging...\n";
+ if(!$LogTransactions) {
+ $LogTransactions = 1;
+ } else {
+ $LogTransactions = 0;
}
- Event->io(cb => \&NewClient,
- poll => 'r',
- desc => 'Lonc listener Unix Socket',
- fd => $socket);
+
+
+ Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
+}
+
+=pod
+
+=head2 ChildStatus
+
+Child USR1 signal handler to report the most recent status
+into the status file.
+
+We also use this to reset the retries count in order to allow the
+client to retry connections with a previously dead server.
+
+=cut
+
+sub ChildStatus {
+ my $event = shift;
+ my $watcher = $event->w;
+
+ Debug(2, "Reporting child status because : ".$watcher->data);
+ my $docdir = $perlvar{'lonDocRoot'};
+
+ open(LOG,">>$docdir/lon-status/loncstatus.txt");
+ flock(LOG,LOCK_EX);
+ print LOG $$."\t".$RemoteHost."\t".$Status."\t".
+ $RecentLogEntry."\n";
+ #
+ # Write out information about each of the connections:
+ #
+ if ($DebugLevel > 2) {
+ print LOG "Active connection statuses: \n";
+ my $i = 1;
+ print STDERR "================================= Socket Status Dump:\n";
+ foreach my $item (keys %ActiveConnections) {
+ my $Socket = $ActiveConnections{$item}->data;
+ my $state = $Socket->GetState();
+ print LOG "Connection $i State: $state\n";
+ print STDERR "---------------------- Connection $i \n";
+ $Socket->Dump(-1); # Ensure it gets dumped..
+ $i++;
+ }
+ }
+ flock(LOG,LOCK_UN);
+ close(LOG);
+ $ConnectionRetriesLeft = $ConnectionRetries;
+ UpdateStatus();
+}
+
+=pod
+
+=head2 SignalledToDeath
+
+Called in response to a signal that causes a chid process to die.
+
+=cut
+
+
+sub SignalledToDeath {
+ my $event = shift;
+ my $watcher= $event->w;
+
+ Debug(2,"Signalled to death! via ".$watcher->data);
+ my ($signal) = $watcher->data;
+ chomp($signal);
+ Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
+ ."died through "."\"$signal\"");
+ #LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
+# ."\"$signal\"");
+ exit 0;
+
+}
+
+=pod
+
+=head2 ToggleDebug
+
+This sub toggles trace debugging on and off.
+
+=cut
+
+sub ToggleDebug {
+ my $Current = $DebugLevel;
+ $DebugLevel = $NextDebugLevel;
+ $NextDebugLevel = $Current;
+
+ Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");
+
}
=pod
@@ -1147,61 +1656,274 @@ sub SetupLoncListener {
=head2 ChildProcess
This sub implements a child process for a single lonc daemon.
+Optional parameter:
+ $socket - if provided, this is a socket already open for listen
+ on the client socket. Otherwise, a new listen is set up.
=cut
sub ChildProcess {
+ # If we are in DieWhenIdle mode, we've inherited all the
+ # events of our parent and those have to be cancelled or else
+ # all holy bloody chaos will result.. trust me, I already made
+ # >that< mistake.
+
+ my $host = GetServerHost();
+ foreach my $listener (keys %parent_dispatchers) {
+ my $watcher = $parent_dispatchers{$listener};
+ my $s = $watcher->fd;
+ if ($listener ne $host) { # Close everyone but me.
+ Debug(5, "Closing listen socket for $listener");
+ $s->close();
+ }
+ Debug(5, "Killing watcher for $listener");
- print "Loncnew\n";
+ $watcher->cancel();
+ delete($parent_dispatchers{$listener});
- # For now turn off signals.
-
- $SIG{QUIT} = IGNORE;
- $SIG{HUP} = IGNORE;
- $SIG{USR1} = IGNORE;
- $SIG{INT} = IGNORE;
- $SIG{CHLD} = IGNORE;
- $SIG{__DIE__} = IGNORE;
+ }
- SetupTimer();
-
- SetupLoncListener();
+ # kill off the parent's signal handlers too!
+ #
+
+ for my $handler (keys %parent_handlers) {
+ my $watcher = $parent_handlers{$handler};
+ $watcher->cancel();
+ delete($parent_handlers{$handler});
+ }
+
+ $I_am_child = 1; # Seems like in spite of it all I may still getting
+ # parent event dispatches.. flag I'm a child.
+
+
+ #
+ # Signals must be handled by the Event framework...
+ #
+
+ Event->signal(signal => "QUIT",
+ cb => \&SignalledToDeath,
+ data => "QUIT");
+ Event->signal(signal => "HUP",
+ cb => \&ChildStatus,
+ data => "HUP");
+ Event->signal(signal => "USR1",
+ cb => \&ChildStatus,
+ data => "USR1");
+ Event->signal(signal => "USR2",
+ cb => \&ToggleTransactionLogging);
+ Event->signal(signal => "INT",
+ cb => \&ToggleDebug,
+ data => "INT");
+
+ # Figure out if we got passed a socket or need to open one to listen for
+ # client requests.
+
+ my ($socket) = @_;
+ if (!$socket) {
+
+ $socket = SetupLoncListener();
+ }
+ # Establish an event to listen for client connection requests.
+
+
+ Event->io(cb => \&NewClient,
+ poll => 'r',
+ desc => 'Lonc Listener Unix Socket',
+ fd => $socket);
- $Event::Debuglevel = $DebugLevel;
+ $Event::DebugLevel = $DebugLevel;
Debug(9, "Making initial lond connection for ".$RemoteHost);
# Setup the initial server connection:
- &MakeLondConnection();
+ # &MakeLondConnection(); // let first work request do it.
- if($ConnectionCount == 0) {
- Debug(1,"Could not make initial connection..\n");
- Debug(1,"Will retry when there's work to do\n");
+ # If We are in diwhenidle, need to accept the connection since the
+ # event may not fire.
+
+ if ($DieWhenIdle) {
+ &accept_client($socket);
}
+
Debug(9,"Entering event loop");
my $ret = Event::loop(); # Start the main event loop.
- die "Main event loop exited!!!";
+ &child_exit (-1,"Main event loop exited!!!");
}
# Create a new child for host passed in:
sub CreateChild {
- my $host = shift;
+ my ($host, $socket) = @_;
+
+ my $sigset = POSIX::SigSet->new(SIGINT);
+ sigprocmask(SIG_BLOCK, $sigset);
$RemoteHost = $host;
- Debug(3, "Forking off child for ".$RemoteHost);
- sleep(5);
- $pid = fork;
+ Log("CRITICAL", "Forking server for ".$host);
+ my $pid = fork;
if($pid) { # Parent
- $ChildHash{$pid} = $RemoteHost;
+ $RemoteHost = "Parent";
+ $ChildHash{$pid} = $host;
+ $HostToPid{$host}= $pid;
+ sigprocmask(SIG_UNBLOCK, $sigset);
+
} else { # child.
ShowStatus("Connected to ".$RemoteHost);
- ChildProcess;
+ $SIG{INT} = 'DEFAULT';
+ sigprocmask(SIG_UNBLOCK, $sigset);
+ if(defined $socket) {
+ &ChildProcess($socket);
+ } else {
+ ChildProcess; # Does not return.
+ }
+ }
+}
+
+# parent_client_connection:
+# Event handler that processes client connections for the parent process.
+# This sub is called when the parent is listening on a socket and
+# a connection request arrives. We must:
+# Start a child process to accept the connection request.
+# Kill our listen on the socket.
+# Parameter:
+# event - The event object that was created to monitor this socket.
+# event->w->fd is the socket.
+# Returns:
+# NONE
+#
+sub parent_client_connection {
+ if ($I_am_child) {
+ # Should not get here, but seem to anyway:
+ &Debug(5," Child caught parent client connection event!!");
+ my ($event) = @_;
+ my $watcher = $event->w;
+ $watcher->cancel(); # Try to kill it off again!!
+ } else {
+ &Debug(9, "parent_client_connection");
+ my ($event) = @_;
+ my $watcher = $event->w;
+ my $socket = $watcher->fd;
+
+ # Lookup the host associated with this socket:
+
+ my $host = $listening_to{$socket};
+
+ # Start the child:
+
+
+
+ &Debug(9,"Creating child for $host (parent_client_connection)");
+ &CreateChild($host, $socket);
+
+ # Clean up the listen since now the child takes over until it exits.
+
+ $watcher->cancel(); # Nolonger listening to this event
+ delete($listening_to{$socket});
+ delete($parent_dispatchers{$host});
+ $socket->close();
+ }
+}
+
+# parent_listen:
+# Opens a socket and starts a listen for the parent process on a client UNIX
+# domain socket.
+#
+# This involves:
+# Creating a socket for listen.
+# Removing any socket lock file
+# Adding an event handler for this socket becoming readable
+# To the parent's event dispatcher.
+# Parameters:
+# loncapa_host - LonCAPA cluster name of the host represented by the client
+# socket.
+# Returns:
+# NONE
+#
+sub parent_listen {
+ my ($loncapa_host) = @_;
+ Debug(5, "parent_listen: $loncapa_host");
+
+ my $socket = &SetupLoncListener($loncapa_host);
+ $listening_to{$socket} = $loncapa_host;
+ if (!$socket) {
+ die "Unable to create a listen socket for $loncapa_host";
+ }
+
+ my $lock_file = &GetLoncSocketPath($loncapa_host).".lock";
+ unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
+
+ my $watcher = Event->io(cb => \&parent_client_connection,
+ poll => 'r',
+ desc => "Parent listener unix socket ($loncapa_host)",
+ fd => $socket);
+ $parent_dispatchers{$loncapa_host} = $watcher;
+
+}
+
+
+# listen_on_all_unix_sockets:
+# This sub initiates a listen on all unix domain lonc client sockets.
+# This will be called in the case where we are trimming idle processes.
+# When idle processes are trimmed, loncnew starts up with no children,
+# and only spawns off children when a connection request occurs on the
+# client unix socket. The spawned child continues to run until it has
+# been idle a while at which point it eventually exits and once more
+# the parent picks up the listen.
+#
+# Parameters:
+# NONE
+# Implicit Inputs:
+# The configuration file that has been read in by LondConnection.
+# Returns:
+# NONE
+#
+sub listen_on_all_unix_sockets {
+ Debug(5, "listen_on_all_unix_sockets");
+ my $host_iterator = &LondConnection::GetHostIterator();
+ while (!$host_iterator->end()) {
+ my $host_entry_ref = $host_iterator->get();
+ my $host_name = $host_entry_ref->[3];
+ Debug(9, "Listen for $host_name");
+ &parent_listen($host_name);
+ $host_iterator->next();
+ }
+}
+
+# server_died is called whenever a child process exits.
+# Since this is dispatched via a signal, we must process all
+# dead children until there are no more left. The action
+# is to:
+# - Remove the child from the bookeeping hashes
+# - Re-establish a listen on the unix domain socket associated
+# with that host.
+# Parameters:
+# The event, but we don't actually care about it.
+sub server_died {
+ &Debug(9, "server_died called...");
+
+ while(1) { # Loop until waitpid nowait fails.
+ my $pid = waitpid(-1, WNOHANG);
+ if($pid <= 0) {
+ return; # Nothing left to wait for.
+ }
+ # need the host to restart:
+
+ my $host = $ChildHash{$pid};
+ if($host) { # It's for real...
+ &Debug(9, "Caught sigchild for $host");
+ delete($ChildHash{$pid});
+ delete($HostToPid{$host});
+ &parent_listen($host);
+
+ } else {
+ &Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
+ }
}
}
+
#
# Parent process logic pass 1:
# For each entry in the hosts table, we will
@@ -1220,11 +1942,7 @@ sub CreateChild {
-ShowStatus("Parent writing pid file:");
-$execdir = $perlvar{'lonDaemons'};
-open (PIDSAVE, ">$execdir/logs/lonc.pid");
-print PIDSAVE "$$\n";
-close(PIDSAVE);
+
ShowStatus("Forming new session");
my $childpid = fork;
@@ -1232,6 +1950,17 @@ if ($childpid != 0) {
sleep 4; # Give child a chacne to break to
exit 0; # a new sesion.
}
+#
+# Write my pid into the pid file so I can be located
+#
+
+ShowStatus("Parent writing pid file:");
+my $execdir = $perlvar{'lonDaemons'};
+open (PIDSAVE, ">$execdir/logs/lonc.pid");
+print PIDSAVE "$$\n";
+close(PIDSAVE);
+
+
if (POSIX::setsid() < 0) {
print "Could not create new session\n";
@@ -1240,29 +1969,250 @@ if (POSIX::setsid() < 0) {
ShowStatus("Forking node servers");
+Log("CRITICAL", "--------------- Starting children ---------------");
+
+LondConnection::ReadConfig; # Read standard config files.
my $HostIterator = LondConnection::GetHostIterator;
-while (! $HostIterator->end()) {
- $hostentryref = $HostIterator->get();
- CreateChild($hostentryref->[0]);
- $HostIterator->next();
+if ($DieWhenIdle) {
+ $RemoteHost = "[parent]";
+ &listen_on_all_unix_sockets();
+} else {
+
+ while (! $HostIterator->end()) {
+
+ my $hostentryref = $HostIterator->get();
+ CreateChild($hostentryref->[0]);
+ $HostHash{$hostentryref->[0]} = $hostentryref->[4];
+ $HostIterator->next();
+ }
}
+$RemoteHost = "Parent Server";
+
# Maintain the population:
ShowStatus("Parent keeping the flock");
-while(1) {
- $deadchild = wait();
- if(exists $ChildHash{$deadchild}) { # need to restart.
- $deadhost = $ChildHash{$deadchild};
- delete($ChildHash{$deadchild});
- Debug(4,"Lost child pid= ".$deadchild.
- "Connected to host ".$deadhost);
- CreateChild($deadhost);
+
+if ($DieWhenIdle) {
+ # We need to setup a SIGChild event to handle the exit (natural or otherwise)
+ # of the children.
+
+ Event->signal(cb => \&server_died,
+ desc => "Child exit handler",
+ signal => "CHLD");
+
+
+ # Set up all the other signals we set up. We'll vector them off to the
+ # same subs as we would for DieWhenIdle false and, if necessary, conditionalize
+ # the code there.
+
+ $parent_handlers{INT} = Event->signal(cb => \&Terminate,
+ desc => "Parent INT handler",
+ signal => "INT");
+ $parent_handlers{TERM} = Event->signal(cb => \&Terminate,
+ desc => "Parent TERM handler",
+ signal => "TERM");
+ $parent_handlers{HUP} = Event->signal(cb => \&Restart,
+ desc => "Parent HUP handler.",
+ signal => "HUP");
+ $parent_handlers{USR1} = Event->signal(cb => \&CheckKids,
+ desc => "Parent USR1 handler",
+ signal => "USR1");
+ $parent_handlers{USR2} = Event->signal(cb => \&UpdateKids,
+ desc => "Parent USR2 handler.",
+ signal => "USR2");
+
+ # Start procdesing events.
+
+ $Event::DebugLevel = $DebugLevel;
+ Debug(9, "Parent entering event loop");
+ my $ret = Event::loop();
+ die "Main Event loop exited: $ret";
+
+
+} else {
+ #
+ # Set up parent signals:
+ #
+
+ $SIG{INT} = \&Terminate;
+ $SIG{TERM} = \&Terminate;
+ $SIG{HUP} = \&Restart;
+ $SIG{USR1} = \&CheckKids;
+ $SIG{USR2} = \&UpdateKids; # LonManage update request.
+
+ while(1) {
+ my $deadchild = wait();
+ if(exists $ChildHash{$deadchild}) { # need to restart.
+ my $deadhost = $ChildHash{$deadchild};
+ delete($HostToPid{$deadhost});
+ delete($ChildHash{$deadchild});
+ Log("WARNING","Lost child pid= ".$deadchild.
+ "Connected to host ".$deadhost);
+ Log("INFO", "Restarting child procesing ".$deadhost);
+ CreateChild($deadhost);
+ }
+ }
+}
+
+
+=pod
+
+=head1 CheckKids
+
+ Since kids do not die as easily in this implementation
+as the previous one, there is no need to restart the
+dead ones (all dead kids get restarted when they die!!)
+The only thing this function does is to pass USR1 to the
+kids so that they report their status.
+
+=cut
+
+sub CheckKids {
+ Debug(2, "Checking status of children");
+ 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";
+ foreach my $host (keys %parent_dispatchers) {
+ print $fh "LONC Parent process listening for $host\n";
+ }
+ foreach my $pid (keys %ChildHash) {
+ Debug(2, "Sending USR1 -> $pid");
+ kill 'USR1' => $pid; # Tell Child to report status.
+ }
+
+}
+
+=pod
+
+=head1 UpdateKids
+
+parent's SIGUSR2 handler. This handler:
+
+=item
+
+Rereads the hosts file.
+
+=item
+
+Kills off (via sigint) children for hosts that have disappeared.
+
+=item
+
+QUITs children for hosts that already exist (this just forces a status display
+and resets the connection retry count for that host.
+
+=item
+
+Starts new children for hosts that have been added to the hosts.tab file since
+the start of the master program and maintains them.
+
+=cut
+
+sub UpdateKids {
+
+ Log("INFO", "Updating connections via SIGUSR2");
+
+ # I'm not sure what I was thinking in the first implementation.
+ # someone will have to work hard to convince me the effect is any
+ # different than Restart, especially now that we don't start up
+ # per host servers automatically, may as well just restart.
+ # The down side is transactions that are in flight will get timed out
+ # (lost unless they are critical).
+
+ &Restart();
+
+}
+
+
+=pod
+
+=head1 Restart
+
+Signal handler for HUP... all children are killed and
+we self restart. This is an el-cheapo way to re read
+the config file.
+
+=cut
+
+sub Restart {
+ &KillThemAll; # First kill all the children.
+ Log("CRITICAL", "Restarting");
+ my $execdir = $perlvar{'lonDaemons'};
+ unlink("$execdir/logs/lonc.pid");
+ exec("$executable");
+}
+
+=pod
+
+=head1 KillThemAll
+
+Signal handler that kills all children by sending them a
+SIGHUP. Responds to sigint and sigterm.
+
+=cut
+
+sub KillThemAll {
+ Debug(2, "Kill them all!!");
+ local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
+ foreach my $pid (keys %ChildHash) {
+ my $serving = $ChildHash{$pid};
+ ShowStatus("Nicely Killing lonc for $serving pid = $pid");
+ Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
+ kill 'QUIT' => $pid;
}
+
+
}
+
+#
+# Kill all children via KILL. Just in case the
+# first shot didn't get them.
+
+sub really_kill_them_all_dammit
+{
+ Debug(2, "Kill them all Dammit");
+ local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
+ foreach my $pid (keys %ChildHash) {
+ my $serving = $ChildHash{$pid};
+ &ShowStatus("Nastily killing lonc for $serving pid = $pid");
+ Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
+ kill 'KILL' => $pid;
+ delete($ChildHash{$pid});
+ my $execdir = $perlvar{'lonDaemons'};
+ unlink("$execdir/logs/lonc.pid");
+ }
+}
+
+=pod
+
+=head1 Terminate
+
+Terminate the system.
+
+=cut
+
+sub Terminate {
+ &Log("CRITICAL", "Asked to kill children.. first be nice...");
+ &KillThemAll;
+ #
+ # By now they really should all be dead.. but just in case
+ # send them all SIGKILL's after a bit of waiting:
+
+ sleep(4);
+ &Log("CRITICAL", "Now kill children nasty");
+ &really_kill_them_all_dammit;
+ Log("CRITICAL","Master process exiting");
+ exit 0;
+
+}
+=pod
+
=head1 Theory
The event class is used to build this as a single process with an