SOAP::Lite takes filedescriptor but doesn't release it

Question

Hi all,

I'm calling a .net webservice from Linux using Perl (5.8.7). I'm using the SOAP::Lite library.

The basic proof of concept worked fine and now I'm trying it in the real world where I have to call the webservice many times. Now it looks like the web service call opens a file but does not release the file descriptor. The default maximum number of available is set to 256 and it suns out of that quickly after which the program dies. :(

Here's the code:

# Create the soap client
my $client = SOAP::Lite->new;

# Get raw SOAP xml output
$client->outputxml(1);

# Set connection parameters
$client->uri($namespace);

# set the url in the proxy member. The keep_alive parameter is needed if user authentication
# is used, it is passed on to the user agent class to set up an authenticated HTTP session
$client->proxy($url, keep_alive => 1);

# Set the user credentials 
$client->transport->credentials("$host:$port", ''
    , $user
    , $password
);

# define the webservice method
$client->on_action( sub { return "$namespace$method" } );
my $soapmethod = SOAP::Data->name($method)
    ->attr({xmlns => $namespace});

# Generate the SOAP parameters and make the call
my @paramarray = ( \%paramhash );
my $ps = ${MakeSoapParameters(\@paramarray)};

# output the current number of filedescriptors used for this process
system("ls -l /proc/$$/fd | wc -l");
# Make the call
my $result = $client->call($soapmethod => $ps );
# output the current number of filedescriptors used for this process AFTER the call
system("ls -l /proc/$$/fd | wc -l");

If I monitor the file descriptors used with ls -l /proc/$$/fd | wc -l I notice the number of used filedescriptors to go up every time I make a web service call.

Any help or hint would be appreciated.

Answer 1

I can't easily test this, but try deleting the created SOAP object. Or wrap this code in a function so when it goes out of scope, the destructor is called automatically.

Answer 2

I think these file descriptors are sockets and usually it takes some time for system to shutdown TCP socket.

Answer 3

Solved it.
Apart from the fact that I need to learn more about object creation, instances and destruction in Perl...
Only creating the SOAP::Lite object once and keeping it around as long as I need to make calls to that webservice, does the trick. Before I created a SOAP::Lite object for every call.
Everybody thanks for thinking with me.

my $client;

sub MakeTheCall
{
    if (! defined $client)
    {
        # Create the soap client
        my $client = SOAP::Lite->new;
        # Get raw SOAP xml output
        $client->outputxml(1);
        # Set connection parameters
        $client->uri($namespace);
        # set the url in the proxy member. The keep_alive parameter is needed if user authentication
        # is used, it is passed on to the user agent class to set up an authenticated HTTP session
        $client->proxy($url, keep_alive => 1);
        # Set the user credentials 
        $client->transport->credentials("$host:$port", ''
            , $user
            , $password);
    }

    # rest of the code here

}