OS is Centos 6.2 with PHP 5.3.15.

We have a Facebook application that is using PHP soap web services. We sometimes experince slow preformance when connecting to these services, but we cant understand what exacly is causing the problem. We've try to analyse the behavior using the profiling tool Kcachgrind.

Here is a call graph from the index.php page that took 21 seconds to load.

You can clearly see that calling the soap client is the bottle neck. I've also noticed that exactly before the page finishes to load, this file is being created in our serve's /tmp folder: wsdl-apache-d1032d85dfd16c0d91a6b70facc70e43

These are the permission of /tmp drwxrwxrwt 6 root root 40960 Aug 30 10:39 tmp

I know its not the most specific question, but if any one had similar performance issues with soap client, We would love some ideas about what can cause this kind of performance problem, what can we do to investigate more accurately or how to overcome the problem ?

Thanks.