Deep recursion problem with SOAP

g0n has asked for the wisdom of the Perl Monks concerning the following question:

Esteemed Monks

I'm trying to do a bit of basic evaluation of Perl SOAP modules for a task. I seem to be failing at the first hurdle. My code is as follows:

Server:

use strict;
use warnings;
use Data::Dumper;


use SOAP::Transport::HTTP;

  SOAP::Transport::HTTP::CGI   
    -> dispatch_to('Demo')     
    -> handle;

  package Demo;

  sub hi {                     
    return "hello, world";     
  }

  sub bye {                    
    return "goodbye, cruel world";
  }
[download]

(Taken from http://www.perl.com/pub/2001/01/soap.html - it's quite an old example but other examples appear similar)

This is running as a cgi script in an Apache 1.3, mod_perl environment.

client:

use strict;
use warnings;

use SOAP::Lite;
  print SOAP::Lite                                             
    -> uri('http://myserver.manheim.co.uk:51111/webservices/vehicle') 
+                                            
    -> proxy('http://myserver.manheim.co.uk:51111/webservices/vehicle/
+soaptest.pl')
    -> hi()                                                    
    -> result;
[download]

When I run the client, nothing happens for a long while, then I get the following message:

[Tue Nov 30 13:44:40 2010] 15689 Digit.pl: Deep recursion on subroutin
+e "utf8::SWASHNEW" at /usr/share/perl/5.10/utf8_heavy.pl line 251.
[Tue Nov 30 13:44:40 2010] 15689 Digit.pl: Deep recursion on subroutin
+e "CGI::Carp::die" at /usr/share/perl/5.10/utf8_heavy.pl line 198.
[download]

I found a suggestion (can't find the URL now) that this is a script error, which sends carp/die into a tailspin, but haven't been able to find a way of tracking down what's wrong with it.

Can anyone suggest a way past this?

Update:

kcotts comment has solved my problem - replacing uri('http://myserver.manheim.co.uk:51111/webservices/vehicle' with uri('http://myserver.manheim.co.uk:51111/Demo' made the thing work immediately. Thanks Corion & ruoso - I'll investigate alternatives to SOAP::Lite.

--------------------------------------------------------------

"If there is such a phenomenon as absolute evil, it consists in treating another human being as a thing."
John Brunner, "The Shockwave Rider".

Comment on Deep recursion problem with SOAP Select or Download Code

Replies are listed 'Best First'.
Re: Deep recursion problem with SOAP by Corion (Patriarch) on Dec 01, 2010 at 12:17 UTC
I assume that somewhere, something is in an encoding, and something tries to decode that in the wrong way. Maybe the data is marked as UTF-8, but sent as "something else". Can you take mod_perl/Apache::Registry out of the picture, or is it not in the picture at all? As a second stab, I would try to look at the data going back and forth either with Wireshark or with SOAP::Trace to get a better picture of what might happen when. Also see this (somewhat disheartening) part in the "Troubleshooting" section of SOAP::Lite: Using SOAP::Lite (or XML::Parser::Expat) in combination with mod_perl causes random segmentation faults in httpd processes.	[reply]
Re: Deep recursion problem with SOAP by kcott (Archbishop) on Dec 01, 2010 at 12:26 UTC
Taking a quick look at the article you linked to, it has: "The uri() identifies the class to the server ..." with examples like: `uri('http://www.soaplite.com/Demo') uri('http://www.soaplite.com/Temperatures')` [download] Perhaps that's where the problem lies. -- Ken	[reply] [d/l]
Re: Deep recursion problem with SOAP by ruoso (Curate) on Dec 01, 2010 at 15:59 UTC
I've been dealing with SOAP for a while already and I must say that the module you should use is XML::Compile::SOAP. Or, if possible, SOAP::Simple (which is just an abstraction for it). If you want to make a web app with support for web services, I'd recommend using Catalyst with Catalyst::Controller::SOAP. (If you're in Catalyst, you can also use Catalyst::Model::SOAP to consume web services). SOAP::Lite is relevant in archeological terms, but it doesn't implement SOAP as it has been used in the last decade. daniel	[reply]


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