Hi, is the database connection created in the child or before it? If it's created inside the child then it'll die ungracefully when the child dies, so put something nice and fluffy to close it before the exit. Otherwise, I don't know I'm afraid.
-----Original Message----- From: Eric Frazier [mailto:[EMAIL PROTECTED] Sent: 16 September 2003 12:57 To: Stephen Hardisty Cc: [EMAIL PROTECTED] Subject: RE: mod_perl v2 Forking Hi, Doing this "works" for me. But I am ending up with some errors that I didn't have before. Of course my bosses would get mad if I posted all of the code involed, but basicly a database connection that was working fine is now returning "mysql server has gone away", meaning that the connection got killed. What is weird/scary, is that if I change your $SIG{CHLD} = 'IGNORE'; back to the handler I was using, the database error goes away, but I am back were I was. Fun huh? :) Thanks, Eric At 03:57 PM 9/16/03 +0100, Stephen Hardisty wrote: >Hi, >I had a problem with 5.8.1 and forking in that I was either getting zombies using the 5.6 examples or the parent was dying, depending on which example was used. The way round I found was to: > ># ignore the child, good rule for life >$SIG{CHLD} = 'IGNORE'; > ># then sort out the socket >my $server = new IO::Socket::INET(LocalPort => $port, > Type => SOCK_STREAM, > Proto => "tcp", > Listen => 5) > or die "some error"; > ># wait for a connection >while(my $client = $server->accept()) >{ > my $pid = fork; > die "Error. Fork: $!\n" unless defined $pid; > > if($pid == 0) > { > # all your child code here > > # when it's done, kill the child: > exit(0); > } >} > >This seemes reasonably stable. If anybody has a better way, then I'm all ears. > >Cheers! > >-----Original Message----- >From: Eric Frazier [mailto:[EMAIL PROTECTED] >Sent: 16 September 2003 12:24 >To: [EMAIL PROTECTED] >Cc: [EMAIL PROTECTED] >Subject: Re: mod_perl v2 Forking > > >Hi, > >I guess this is off topic for this list, since I would be doing this no >matter if I was running CGI or mod_perl or whatever. I am pretty desparate >to get this working, and if anyone wants to earn some cash helping me fix >things PLEASE call me at 250 655-9513. > >I have been trying to accomplish the same thing as Cameron, but with the >detaching stuff it seemed a lot easier to make a server with IO::Select and >not actually start the server from mod_perl. The end result hopefully will >be a web user being able to start some things that take time, but not screw >things up by interrupting them. > >But then I found I was using 5.8.. Thanks to a guy on comp.lang.perl.misc I >know that there is a change in how signals are handled, they call it >deferred signal handling because Perl now is suppose to wait until the >Interpeter is in a safe state. As I understand it this might avoid some >things like core dumps or other errors related to dieing while trying to do >something besides dieing. > >The thing is somehow this ends up killing off my parent process, just like >in this post: > >http://www.mail-archive.com/[EMAIL PROTECTED]/msg43989.html > >So this is happening to me as well, however the guy in the above example had >his problem solved by using Errno and looking for EINTR if that error is >raised then catch it and move on, > >I did get one maybe helpfull thing from my log: > >Erro was %! -------- >./franken_socket.pl 8607: got - CHLD > at Tue Sep 16 02:17:42 2003 >I got forked >./franken_socket.pl 8599: begat 8607 at Tue Sep 16 02:17:40 2003 >begat 8607 >./franken_socket.pl 8599: got - CHLD > at Tue Sep 16 02:17:54 2003 >./franken_socket.pl 8599: main 8607 -- reaped 1 at Tue Sep 16 02:17:54 2003 >reaped 1Erro was No child processes %! -------- > >So it looks like the parent got killed on that error "No child process" >This code works just fine on 5.6 since it is about 150% from examples :) >The above is the result of connecting, doing a "who", and doing "dienow" to >test the alarm. > >I also found this: > >http://archive.develooper.com/[EMAIL PROTECTED]/msg03022.html > >Which totaly describes my problem as well, but shows it happening with perl >5.8.1.. > > >>I'd imagine that your accept() isn't being restarted. How does it work >>if you change the loop to look like this? > >> use Errno; > >> while (1) { >> my $client = $server->accept or do { >> next if $!{EINTR}; >> last; >> }; >> spawn(\&function, "whatever"); >> } > >#!/usr/bin/perl -w > >## new frankenstein! > > use strict; > use POSIX (); > use POSIX 'WNOHANG'; > use Errno; > use IO::Socket; > use FindBin (); > use File::Basename (); > use File::Spec::Functions; > use Net::hostent; > use Carp; > > > $|=1; > my $pid; > >open (DIED, ">>/var/log/daemon_log") or warn "$!"; >sub logmsg { print DIED "$0 $$: @_ at ", scalar localtime, "\n" } > >my $listen_socket = IO::Socket::INET->new(LocalPort => 1081, > LocalAddr => '127.0.0.1', > Proto => 'tcp', > Listen => SOMAXCONN, > Reuse => 1 ) >or die "can make a tcp server on port 1080 $!"; > > > # make the daemon cross-platform, so exec always calls the script > # itself with the right path, no matter how the script was invoked. > my $script = File::Basename::basename($0); > my $SELF = catfile $FindBin::Bin, $script; > # POSIX unmasks the sigprocmask properly > my $sigset = POSIX::SigSet->new(); > my $action = POSIX::SigAction->new('sigHUP_handler', > $sigset, > &POSIX::SA_NODEFER); > my $action_alrm = POSIX::SigAction->new('sigALRM_handler', > $sigset, > &POSIX::SA_NODEFER); > > > POSIX::sigaction(&POSIX::SIGHUP, $action); > POSIX::sigaction(&POSIX::SIGALRM, $action_alrm); > > sub sigHUP_handler { > print "got SIGHUP\n"; > exec($SELF, @ARGV) or die "Couldn't restart: $!\n"; > } > sub sigALRM_handler { > print "got ALARM timeout\n"; > > } > > $SIG{CHLD} = \&REAPER_NEW; > > sub REAPER { > $SIG{CHLD} = \&REAPER; # loathe sysV > my $waitedpid = wait; > logmsg "reaped $waitedpid" . ($? ? " with exit $?" : ''); > } > > sub REAPER_NEW { > logmsg "got - @_\n"; > my $wpid = undef; > while ($wpid = waitpid(-1,WNOHANG)>0) { > > logmsg "main $pid -- reaped $wpid" . ($? ? " with exit $?" : '') >; > print DIED "reaped $wpid" . ($? ? " with exit $?" : ''); > > } > } > > > print "PID: $$\n"; > print "ARGV: @ARGV\n"; > print "[Server $0 accepting clients]\n"; > >#while (my $connection = $listen_socket->accept()) { >while (1) { > my $connection = $listen_socket->accept() or do { > next if $!{EINTR}; > last; > }; > > print DIED "Erro was $! %! --------\n"; >$connection->autoflush(1); ## missing seemed to cause client problem, but >not telnet > > if (!defined($pid = fork)) { > logmsg "cannot fork: $!"; > > }elsif ($pid) { > logmsg "begat $pid"; > print DIED "begat $pid\n"; > }else{ > # else i'm the child -- go spawn > print $connection "Command?"; > > while ( <$connection> ){ > > my $return_value = undef; > > if (/quit|exit/i) { last; } > elsif (/closeme/i ) {$connection->close(); } > elsif (/date|time/i) { printf $connection "%s\n", scalar >localtime; } > elsif (/who/i ) { print $connection `who 2>&1`;} > elsif (/dienow/i ) { alarm 2; } > elsif (/dieT/i ) { die; } > > > > #REAPER_NEW($pid) if $return_value; > > print $connection "Command?"; > > print DIED "I got forked\n"; >} > exit(0); > > #STDIN->fdopen($connection,"r") || die "can't dup client to stdin"; > #STDOUT->fdopen($connection,"w") || die "can't dup client to stdout" >; > #STDERR->fdopen($connection,"w") || die "can't dup stdout to stderr"; > > ### FORKed code here.. > > } ## end while <$connection> > >} ## end else > >close ($listen_socket); > > > > >At 01:18 AM 9/16/03 -0700, Stas Bekman wrote: >>Cameron B. Prince wrote: >> >>> I have a report generator program written in Perl that I need to start from >>> a CGI. The program takes about 15 minutes to run, so I must fork or double >>> fork. I have two goals: > >(250) 655 - 9513 (PST Time Zone) > >"Inquiry is fatal to certainty." -- Will Durant > > > > > >________________________________________________________________________ >This email has been scanned for all viruses by the MessageLabs Email >Security System. For more information on a proactive email security >service working around the clock, around the globe, visit >http://www.messagelabs.com >________________________________________________________________________ > >________________________________________________________________________ >This email has been scanned for all viruses by the MessageLabs Email >Security System. For more information on a proactive email security >service working around the clock, around the globe, visit >http://www.messagelabs.com >________________________________________________________________________ > (250) 655 - 9513 (PST Time Zone) "Inquiry is fatal to certainty." -- Will Durant ________________________________________________________________________ This email has been scanned for all viruses by the MessageLabs Email Security System. For more information on a proactive email security service working around the clock, around the globe, visit http://www.messagelabs.com ________________________________________________________________________ ________________________________________________________________________ This email has been scanned for all viruses by the MessageLabs Email Security System. For more information on a proactive email security service working around the clock, around the globe, visit http://www.messagelabs.com ________________________________________________________________________
