Hi guys,
Thanks for your responses.
Here's the code flow:
Please note that error does not occur in case I run 3 child process. Even sometimes all 6 run without any error. Find the ulimit output below:
xxxx.pl:
======

Read more... (3 kB)

ulimit output


---

core file size (blocks) unlimited
data seg size (kbytes) unlimited
file size (blocks) unlimited
open files 1024
pipe size (512 bytes) 10
stack size (kbytes) 8192
cpu time (seconds) unlimited
max user processes 29995
virtual memory (kbytes) unlimited


---

I ran the program by increasing the ulimit to 16M but no luck!
System free disk space is significantly high..4-5G, and the files that are being created are quite small in size ( total size of all the files may be 1G or so)
The way I am checking for error is by following code snippet:


if ($!)
{
    print "Error occured: $!";
        # reset the error so that we can catch next genuine error cond
+ition
        $! = 0;
}
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Note that after this piece prints error ( which means the program ran out of memory, program still runs (remaining passes of the loop, other child processes) and there is no error for sometime. Error is generated ( though not always) again after sometime. So if the error was precisely due to some concrete memory issue then once error is generated (momory exhausted) all 6 child processes should fail to proceed and all of them should throw the same error. Which is not happening!!!

Edited by davido to add code and readmore tags.

I think the point has already been made. You aren't supposed to look in $! unless an error has just occured. For instance

print $fh "foo\n" 
  or die "Error writing: $!";
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Since we dont know where your $! testing code occurs, theres any number of possibilities as to how $! can be set. For all we know some part of your code catches an error at some point and leaves $! set. Consider the following program:

perl -le "print BLAH 'foo' or warn $!; print 'foo'; print $!";
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The error message persists long after its relevent.

As and aside: please use <code> tags around any code you post. At the very least it will avoid errors like the one at the bottom of your post. ;-)

HTH

---
demerphq

...
my $x = db_login( ... ) || die( "Could not open ..." );
my $xx = db_login( ... ) || die( "Could not open ..." );
my $xxx = db_login( ... ) || die( "Could not open ..." );
my $xxxx = db_login( ... ) || die( "Could not open ..." );
my %j = <data from DB>
my %jj = <data from DB>;
my %jjjj = <data from DB>;
my $pid1 = &executeChild( ....... );
my $pid2 = &executeChild( ....... );
my $pid3 = &executeChild( ....... );
my $pid4 = &executeChild( ....... );
my $pid5 = &executeChild( ....... );
my $pid6 = &executeChild( ....... );
...
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Definitely time to refactor. Or even better yet, start from scratch if time and budget allow for it.

Check return codes from everything that can fail. In particular, see of fork is returning undef. I bet that's your problem, though it's just my intuition.

If you can verify that the error is indeed ENOSPC with,

use Errno;
warn "Yes, it's ENOSPC\n" if ENOSPC == 0+$!;
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This would be easier to diagnose if you showed code.

What is happening is, once in a while these processes are throwing "Not enough space" error in $! and continuing running. I dont see this error unless I print $!.

My question is, why is this happening?

$! = 12;
die "Uh oh: $!";
__END__
Uh oh: Not enough space at - line 2.
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