The good news is that Mr. Mackenna got it! If I set "KeepAlive Off" in
apache2.conf then it all works fine. Below is a functioning long
process thingy which works with "KeepAlive On" and Firefox. I just hope
it works with MSIE ...
#!/usr/bin/perl
use strict;
use Apache2::Const -compile => qw(:conn_keepalive);
use Apache2::Log(); # defines warn
use Apache2::RequestUtil(); # defines push_handlers
use Apache2::Connection();
use Apache2::RequestRec();
my $r = shift;
my $c = $r->connection();
$c->keepalive(Apache2::Const::CONN_CLOSE);
$r->push_handlers(PerlCleanupHandler => \&cleanup );
$r->err_headers_out->set(Location => 'http://...index.pl');
$r->status(Apache2::Const::REDIRECT);
return Apache2::Const::REDIRECT;
sub cleanup {
my ($r) = @_;
$r->warn("Starting cleanup");
foreach my $num (1..5) {
$r->warn("Number is $num");
sleep 2;
}
return Apache2::Const::OK;
}
####
So, thanks again, and as for the warning from William T., well my
spin-off processes are maybe 10s-10m long and not a driving feature, but
I will have to keep my eye on them.
Tosh
macke...@animalhead.com wrote:
The warning from William T. made me think to ask:
Does your site have "KeepAlive On" in httpd.conf?
(If not I can't think of anything to suggest...)
If so, try adding this as part of the redirect:
use Apache2::Connection();
use Apache2::RequestRec();
...
my $c = $r->connection();
$c->keepalive(Apache2::Const::CONN_CLOSE);
This will keep your process (which is about to do a "long"
cleanup) from automatically getting the redirected request
from the browser.
Hopefully the root httpd will know that this "redirecting"
child has not finished the complete cycle, and will launch
other children if needed to process the redirected request
plus any other requests.
Of course William is right that if lots of requests are
arriving that need such cleanup, and the cleanup really does
take a long time on average, you are likely to pile up
more children than your household income (I'm sorry I meant
to say your server :-) can support.
Good Luck,
cmac
On Jan 26, 2010, at 2:27 PM, Tosh Cooey wrote:
So this works almost perfectly... Almost because:
#!/usr/bin/perl
use strict;
use Apache2::Const(); # defines OK
use Apache2::Log(); # defines warn
use Apache2::RequestUtil(); # defines push_handlers
my $r = shift;
$r->push_handlers(PerlCleanupHandler => \&cleanup );
$r->headers_out->set(Location => 'http://...index.pl');
$r->status(Apache2::Const::REDIRECT);
return Apache2::Const::REDIRECT;
sub cleanup {
my ($r) = @_;
$r->warn("Starting cleanup");
foreach my $num (1..5) {
$r->warn("Number is $num");
sleep 2;
}
return Apache2::Const::OK;
}
######## test.pl
It seems if you take the above program and hit it with Firefox (3.5.7
and 3.6) it may take 10 seconds (5 x sleep 2) before Firefox does the
redirect. Safari 4.0.4 seems fine. curl works as well :)
I said "may" above because it's not consistent. If you launch Firefox
fresh and hit the above program it may redirect instantly, but then
subsequent hits will illustrate the delay. I'm also seeing varying
behaviour on a different server that has no Basic Auth, but always the
problem is there.
Can anyone else reproduce this?
Thank-you!
Tosh
macke...@animalhead.com wrote:
at(1) is a Unix command to start a process.
Assuming you're on a Unix/Linux box, type "man at" to get the story.
A cleanup handler is more pleasant than a prostate exam.
You can spend your life waiting for others. Just write a
routine called "cleanup" and have it do something like
make a log entry.
use Apache2::Const(); # defines OK
use Apache2::Log(); # defines warn
use Apache2::RequestUtil(); # defines push_handlers
...
sub cleanup {
my ($r) = @_;
$r->warn("cleanup was here");
return Apache2::Const::OK;
}
Then put a call like the one below in your ModPerl::Registry routine.
If the log entry shows up in error_log, you're on your way...
Good Luck,
cmac
P.S. Google doesn't index some sites well.
Look at http://perl.apache.org/docs/2.0/
particularly its API link.
On Jan 25, 2010, at 5:49 PM, Tosh Cooey wrote:
Sorry, I couldn't figure out what at(1) meant (or maybe ap(1) which
you say below) is that an abbreviation for something?
And Perrin saying "cleanup handler" is right up there with "prostate
exam" in my list of things to get into, both scare me!
Of course at some point a man needs to do both...
So... If this magic: $r->push_handlers(PerlCleanupHandler =>
\&cleanup); is available in ModPerl::Registry context then I will
attempt to force all my forks into early retirement and work the
problem out that way.
Unfortunately Google doesn't return an easy answer, anybody know
this before I spend all day tomorrow in my struggle?
Thank-you all again,
Tosh
macke...@animalhead.com wrote:
You made no comment on the links I sent you earlier today.
They had lots of good advice. Particularly the first one
suggested not forking the Apache process, but using an
ap(1) call to start a process to do the additional processing.
OK, the ap(1) alternative was a bit light on details.
How about the alternative offered by Perrin Hawkins in the
same thread, of using a cleanup handler to do the follow-up
processing rather than a forked process.
From p. 107 of "mod_per2 User's Guide":
$r->push_handlers(PerlCleanupHandler => \&cleanup);
print $in->redirect... # to redirect the browser
Now cleanup (which receives $r as its operand) can do
whatever slow stuff you need to, can probably use DBI
without all the pain you have below, and can access the
request to find out what to do.
In some past context you may have learned how to get hold of
a $r to use in these calls, and hopefully you're no longer
scared of $r. But there does remain the question of whether
a ModPerl::Registry module can do such calls.
Hopefully someone who knows can chime in on this.
If not, for me it would be worth the editing of getting the
module out from under ModPerl::Registry and into the "native
mode" of SetHandler modperl.
Best of luck,
cmac
On Jan 25, 2010, at 1:54 PM, Tosh Cooey wrote:
Ok, then maybe I need to supply some code here to try and get
clarification:
mailfile.pl
###########
use strict;
...
use POSIX;
#gather needed modules and objects
my $fileOBJ = new MyOBJS::FILE($in->param('id'));
my $clientOBJ = new ...
my $userOBJ = new ...
# All OBJjects have a {DBH} property which is their DB handle
# I hear I have to disconnect these first, do I have to disconnect
ALL?
$fileOBJ->{DBH}->disconnect;
$SIG{CHLD} = 'IGNORE';
my $pid;
if ($pid = fork) {
warn "Pid = $pid";
} elsif (defined $pid) {
close(STDOUT);
close(STDIN);
close(STDERR);
# chdir to /, stops the process from preventing an unmount
chdir '/' or die "Can't chdir to /: $!";
# dump our STDIN and STDOUT handles
open STDIN, '/dev/null' or die "Can't read /dev/null: $!";
open STDOUT, '>/dev/null' or die "Can't write to /dev/null: $!";
# redirect for logging
open STDERR, '>/tmp/stderr' or die "Can't write to
/tmp/stderr: $!";
# Prevent locking to apache process
setsid or die "Can't start a new session: $!";
# Create file download link email
my $mailSTR = ...
# Send the mail possibly to many people
foreach my $person (@people) {
open(MAIL, '|' . &cfg('sendmail_location') . ' -t');
print MAIL $mailSTR;
close(MAIL);
}
# Need to recreate the DBI connection on the $fileOBJ I hear
$fileOBJ = new MyOBJS::FILE($in->param('id'));
# Do some SQL to update the $fileOBJ status based on mailout
$fileOBJ->sql....
# create LOGGING Objects to log stuff
my $logOBJ = new ...
$logOBJ->sql...
CORE::exit(0);
}
print $in->redirect... # For the parent to redirect the browser
# Done.
Is there a glaring mistake in the above?
The parent does no more DB stuff, it just sends a redirect.
This runs under ModPerl::Registry.
I'd like to get at least one thing working tonight, either the
forking or the DBI, I'll be happy!
Tosh
Perrin Harkins wrote:
On Mon, Jan 25, 2010 at 3:48 PM, Tosh Cooey <t...@1200group.com>
wrote:
Thanks Perrin, the forking, my child got a PID of 30033 and then
afterwards
when I checked the processes (ps) for 30033 I see:
[apache2] <defunct>
Is that what's supposed to happen?
After you call exit? No. It should be gone. That's a zombie
process.
That PM thread seems to indicate that I must disconnect every
DBH, not just
the ones that I will use.
Either that, or you need to set InactiveDestroy on all of them in
the
child process. Otherwise, when the child exits, it messes up all of
them for the parent.
Are you also suggesting the use of
Parallel::ForkManager for forks?
No. The DBI stuff is the same with either.
- Perrin
--
McIntosh Cooey - Twelve Hundred Group LLC - http://www.1200group.com/
--
McIntosh Cooey - Twelve Hundred Group LLC - http://www.1200group.com/
--
McIntosh Cooey - Twelve Hundred Group LLC - http://www.1200group.com/
--
McIntosh Cooey - Twelve Hundred Group LLC - http://www.1200group.com/
