In PHP how can you clear a WSDL cache?

Remove all wsdl* files in your /tmp folder on the server.

WSDL files are cached in your default location for all cache files defined in php.ini. Same location as your session files.

if you already deployed the code or can't change any configuration, you could remove all temp files from wsdl:

rm /tmp/wsdl-*

You can safely delete the WSDL cache files. If you wish to prevent future caching, use:

ini_set("soap.wsdl_cache_enabled", 0);

or dynamically:

$client = new SoapClient('http://somewhere.com/?wsdl', array('cache_wsdl' => WSDL_CACHE_NONE) );

I recommend using a cache-buster in the wsdl url.

In our apps we use a SVN Revision id in the wsdl url so the client immediately knows of changing structures. This works on our app because, everytime we change the server-side, we also need to adjust the client accordingly.

$client = new SoapClient('http://somewhere.com/?wsdl&rev=$Revision$');

This requires svn to be configured properly. Not on all repositories this is enabled by default.

In case you are not responsible for both components (server,client) or you don't use SVN you may find another indicator which can be utilised as a cache-buster in your wsdl url.