[LON-CAPA-cvs] cvs: loncom / lonc

foxr lon-capa-cvs@mail.lon-capa.org
Fri, 08 Mar 2002 03:56:19 -0000


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foxr		Thu Mar  7 22:56:19 2002 EDT

  Modified files:              
    /loncom	lonc 
  Log:
  Corrected and simplified child management logic:
  1. Removed SIGCHLD handler, made parent main loop
     just be a wait, rather than sleep.
  2. Corrected book-keeping error in lonc's make_child_process
     which caused single child death to trigger attempts to
     restart all children...whether actually dead or not.
  
  
  
  
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Index: loncom/lonc
diff -u loncom/lonc:1.31 loncom/lonc:1.32
--- loncom/lonc:1.31	Sun Mar  3 13:13:07 2002
+++ loncom/lonc	Thu Mar  7 22:56:19 2002
@@ -5,7 +5,7 @@
 # provides persistent TCP connections to the other servers in the network
 # through multiplexed domain sockets
 #
-# $Id: lonc,v 1.31 2002/03/03 18:13:07 harris41 Exp $
+# $Id: lonc,v 1.32 2002/03/08 03:56:19 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -57,12 +57,13 @@
 use Fcntl;
 use Tie::RefHash;
 use Crypt::IDEA;
-use Net::Ping;
+#use Net::Ping;
 use LWP::UserAgent();
 
 $status='';
 $lastlog='';
 $conserver='SHELL';
+$DEBUG = 0;			# Set to 1 for annoyingly complete logs.
 
 # -------------------------------- Set signal handlers to record abnormal exits
 
@@ -158,47 +159,53 @@
 &status("Forking ...");
 
 foreach $thisserver (keys %hostip) {
-    if (&online($hostname{$thisserver})) {
+    #if (&online($hostname{$thisserver})) {
        make_new_child($thisserver);
-    }
+    #}
 }
 
 &logthis("Done starting initial servers");
 # ----------------------------------------------------- Install signal handlers
 
-$SIG{CHLD} = \&REAPER;
+
 $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
 $SIG{HUP}  = \&HUPSMAN;
 $SIG{USR1} = \&USRMAN;
 
 # And maintain the population.
 while (1) {
-    &status("Sleeping");
-    sleep;                          # wait for a signal (i.e., child's death)
+    my $deadpid = wait;		# Wait for the next child to die.
                                     # See who died and start new one
     &status("Woke up");
     my $skipping='';
-    foreach $thisserver (keys %hostip) {
-        if (!$childpid{$thisserver}) {
-	    if (($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 {
-               $skipping.=$thisserver.' ';
-           } 
-               
-        }       
-    }
-    if ($skipping) { 
-       &logthis("<font color=blue>WARNING: Skipped $skipping</font>");
+
+    if(exists($children{$deadpid})) {
+
+	$thisserver = $children{$deadpid}; # Look name of dead guy's peer.
+
+	delete($children{$deadpid}); # Get rid of dead hash entry.
+
+	if($childatt{$thisserver} < $childmaxattempts) {
+	    $childatt{$thisserver}++;
+	    &logthis(
+	       "<font color=yellow>INFO: Trying to reconnect for $thisserver "
+            ."($childatt{$thisserver} of $childmaxattempts attempts)</font>"); 
+	    make_new_child($thisserver);
+	
+	}
+	else {
+	    $skipping .= $thisserver.' ';
+	}
+	if($skipping) {
+	    &logthis("<font color=blue>WARNING: Skipped $skipping</font>");
+  
+	}
     }
+
 }
 
 
+
 sub make_new_child {
    
     $newserver=shift;
@@ -217,7 +224,7 @@
         sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";
         $children{$pid} = $newserver;
-        $childpid{$conserver} = $pid;
+        $childpid{$newserver} = $pid;
         return;
     } else {
         $conserver=$newserver;
@@ -238,9 +245,10 @@
 # -------------------------------------------------------------- Open other end
 
 &openremote($conserver);
-
+	&logthis("<font color=green> Connection to $conserver open </font>");
 # ----------------------------------------- We're online, send delayed messages
     &status("Checking for delayed messages");
+
     my @allbuffered;
     my $path="$perlvar{'lonSockDir'}/delayed";
     opendir(DIRHANDLE,$path);
@@ -250,7 +258,7 @@
     foreach (@allbuffered) {
         &status("Sending delayed: $_");
         $dfname="$path/$_";
-        &logthis('Sending '.$dfname);
+        if($DEBUG) { &logthis('Sending '.$dfname); }
         my $wcmd;
         {
          my $dfh=IO::File->new($dfname);
@@ -289,6 +297,7 @@
             &logperm("S:$conserver:$bcmd");
         }        
     }
+	if($DEBUG) { &logthis("<font color=green> Delayed transactions sent"); }
 
 # ------------------------------------------------------- Listen to UNIX socket
 &status("Opening socket");
@@ -300,11 +309,11 @@
        my $st=120+int(rand(240));
        &logthis(
          "<font color=blue>WARNING: ".
-         "Can't make server socket ($st secs): $@</font>");
+         "Can't make server socket ($st secs): $@ .. exiting</font>");
        sleep($st);
        exit; 
      };
-
+   
 # -----------------------------------------------------------------------------
 
 &logthis("<font color=green>$conserver online</font>");
@@ -329,8 +338,8 @@
     # check for new information on the connections we have
 
     # anything to read or accept?
-    foreach $client ($select->can_read(0.1)) {
 
+    foreach $client ($select->can_read(100.0)) {
         if ($client == $server) {
             # accept a new connection
             &status("Accept new connection: $conserver");
@@ -356,6 +365,7 @@
 
             $inbuffer{$client} .= $data;
 
+
             # test whether the data in the buffer or the data we
             # just read means there is a complete request waiting
             # to be fulfilled.  If there is, set $ready{$client}
@@ -365,12 +375,12 @@
             }
         }
     }
-
+    
     # Any complete requests to process?
     foreach $client (keys %ready) {
         handle($client);
     }
-
+ 
     # Buffers to flush?
     foreach $client ($select->can_write(1)) {
         # Skip this client if we have nothing to say
@@ -426,16 +436,18 @@
     # send output to $outbuffer{$client}
     my $client = shift;
     my $request;
-
     foreach $request (@{$ready{$client}}) {
 # ============================================================= Process request
         # $request is the text of the request
         # put text of reply into $outbuffer{$client}
 # ------------------------------------------------------------ Is this the end?
+	if($DEBUG) {
+     &logthis("<font color=green> Request $request processing starts</font>");
+        }
         if ($request eq "close_connection_exit\n") {
 	    &status("Request close connection");
            &logthis(
-     "<font color=red>CRITICAL: Request Close Connection</font>");
+     "<font color=red>CRITICAL: Request Close Connection ... exiting</font>");
            $remotesock->shutdown(2);
            $server->close();
            exit;
@@ -466,6 +478,9 @@
         &status("Received reply: $request");
         alarm(0);
     };
+    if($DEBUG) { 
+	&logthis("<font color=green> Request data exchange complete");
+    }
     if ($@=~/timeout/) { 
        $answer='';
        &logthis(
@@ -494,11 +509,16 @@
         }
 
      &status("Completed: $request");
-
+	if($DEBUG) {
+	    &logthis("<font color=green> Request processing complete</font>");
+	}
 # ===================================================== Done processing request
     }
     delete $ready{$client};
 # -------------------------------------------------------------- End non-forker
+    if($DEBUG) {
+	&logthis("<font color=green> requests for child handled</font>");
+    }
 }
 # ---------------------------------------------------------- End make_new_child
 }
@@ -522,6 +542,7 @@
     my $conserver=shift;
 
 &status("Opening TCP");
+    my $st=120+int(rand(240)); # Sleep before opening:
 
 unless (
   $remotesock = IO::Socket::INET->new(PeerAddr => $hostip{$conserver},
@@ -529,14 +550,15 @@
                                       Proto    => "tcp",
                                       Type     => SOCK_STREAM)
    ) { 
-       my $st=120+int(rand(240));
+
        &logthis(
-"<font color=blue>WARNING: Couldn't connect ($st secs): $@</font>");
+"<font color=blue>WARNING: Couldn't connect to $conserver ($st secs): $@</font>");
        sleep($st);
        exit; 
      };
 # ----------------------------------------------------------------- Init dialog
 
+&logthis("<font color=green>INFO Connected to $conserver, initing </font>");
 &status("Init dialogue: $conserver");
 
      $SIG{ALRM}=sub { die "timeout" };
@@ -554,7 +576,7 @@
      $SIG{__DIE__}=\&catchexception;
  
      if ($@=~/timeout/) {
-	 &logthis("Timed out during init");
+	 &logthis("Timed out during init.. exiting");
          exit;
      }
 
@@ -597,7 +619,7 @@
    sleep($st);
    exit;
 }
-
+    &logthis("<font color=green> Remote open success </font>");
 }
 
 
@@ -616,15 +638,15 @@
 
 # -------------------------------------- Routines to see if other box available
 
-sub online {
-    my $host=shift;
-    &status("Pinging ".$host);
-    my $p=Net::Ping->new("tcp",20);
-    my $online=$p->ping("$host");
-    $p->close();
-    undef ($p);
-    return $online;
-}
+#sub online {
+#    my $host=shift;
+#    &status("Pinging ".$host);
+#    my $p=Net::Ping->new("tcp",20);
+#    my $online=$p->ping("$host");
+#    $p->close();
+#    undef ($p);
+#    return $online;
+#}
 
 sub connected {
     my ($local,$remote)=@_;
@@ -635,7 +657,7 @@
     unless ($hostname{$local}) { return 'local_unknown'; }
     unless ($hostname{$remote}) { return 'remote_unknown'; }
 
-    unless (&online($hostname{$local})) { return 'local_offline'; }
+    #unless (&online($hostname{$local})) { return 'local_offline'; }
 
     my $ua=new LWP::UserAgent;
     
@@ -654,17 +676,6 @@
 }
 
 
-sub REAPER {                        # takes care of dead children
-    $SIG{CHLD} = \&REAPER;
-    my $pid = wait;
-    my $wasserver=$children{$pid};
-    &logthis("<font color=red>CRITICAL: "
-     ."Child $pid for server $wasserver died ($childatt{$wasserver})</font>");
-    delete $children{$pid};
-    delete $childpid{$wasserver};
-    my $port = "$perlvar{'lonSockDir'}/$wasserver";
-    unlink($port);
-}
 
 sub hangup {
     foreach (keys %children) {
@@ -892,8 +903,6 @@
 
 SIGCHLD
 
-Parent signal assignment:
- $SIG{CHLD} = \&REAPER;
 
 Child signal assignment:
  none

--foxr1015559779--