Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks,

I am trying to use SOAP::Lite to test our server under load. I need HTTP keep_alive capability so that all the request are made over the same connection.
The design I have in mind is to fork every service request. The pseudo code is something like this... 

use SOAP::Lite;

my $soap_client = SOAP::Lite->uri('myuri')
                    ->proxy('http://serviceendpoint',
                            timeout    => 30,
                            keep_alive => 1);
for (1 .. 10) {
    if(fork()) {
      #--- do something in parent
      #-- like wait for time specified by load rate etc.
      sleep(1); #--- just for pseudo code
    }
    else {
       $soap_client->call('SomeMethod',$paramter);
    }
}

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With the above what I am observing is that the SOAP client object in the forked child process closes the TCP connection after it gets the response from the server. I think this is because of the use of fork and the copy of the object going away after the child process is done. Is there a way around this so that the soap client uses the same connection (transport) across multiple forked processes?
Thanks. DP.

p.s.: I tried a bit to play around with IPC::Shareable but get some cryptic error Can't store CODE items at blib/lib/Storable.pm

p.p.s: In reality I am achieving the forking using POE and POE::Wheel::Run. The issue is the same as with the use of basic fork as above.

Replies are listed 'Best First'.
Re: SOAP::Lite How to use persistent connection across fork process
by zentara (Cardinal) on Jul 10, 2012 at 16:31 UTC
    Threads is perfect for this. You could create 1 Soap::Lite object and keep using it over and over. This is untested, but is simple to understand what is happening. I would use Glib or AnyEvent to make a timer to wake the thread, but this while loop shows the simplicity. 
    #!/usr/bin/perl
use warnings;
use strict;
use threads;
use threads::shared;

my $tgo:shared = 0;;
my $tdie:shared = 0;

my $thread = threads->new(\&check_it);

# setup a timer or use a while loop here
# probably need to Control-C out of this loop
# unless you add some keyboard checking for a q
# or whatever

while(1){
   sleep 10;
   $tgo = 1;
  print "starting check\n";
}

$tdie = 1;
$thread->join;
print "done press any key to exit\n";
<>;
###################################################

sub check_it {

  use SOAP::Lite;
  $|++; 

  # this will be persistent in the thread
  my $soap_client = SOAP::Lite->uri('myuri')
                    ->proxy('http://serviceendpoint',
                            timeout    => 30,
                            keep_alive => 1);

  while(1){

     if($tdie == 1){ return }; 
      
       if ( $tgo == 1 ){

        print "soap start\n";   
        $soap_client->call('SomeMethod',$paramter);
        print "soap done\n";

        $tgo = 0; #turn off self before returning to sleep     

       }else
         { sleep 1 }
  }

}
__END__

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