Re: [xmlblaster-devel] Why do xml-rpc sessions w/ callbacks time out?

[Marcel Ruff <mr at marcelruff.info>]

Brad Clements wrote:
> I'm using a modified pyBlaster to execute a long-running process with callbacks.
>
> I've added code to the callback component of pyblaster to notice if it has not received a ping 
> in 5 minutes to then attempt to login again.
>
> But, from examining the xmlBlaster logging output, it seems to deactive the client-side of the 
> xml-rpc session after inactivity, even though the callback associated with that client *was* 
> answering ping requests.
>
> Perhaps I'm reading the log output incorrectly.
>
> Can anyone confirm this?
>
> If an xml-rpc client has a callback URL associated with it, and if that callback continues to 
> answer ping requests, should the client handle timeout due to inactivity? I think it should not.

You are right, the pings don't prevent from session timeout during client inactivity.

On connect() or login() you need to set your session timeout:

  <qos>
    <session timeout='0'/>
    <callback type='XMLRPC'>http://localhost:8081</callback>
  </qos>

0 milliseconds sets the session to last forever, for details see

  http://www.xmlblaster.org/xmlBlaster/doc/requirements/interface.connect.html

I have added an example to pyBlaster.py in the current cvs.

> How do I change the idle timeout for xml-rpc clients? Can it be done on the client handle, or 
> do I need to change a configuration file entry somewhere?
>
> --
>
> It seems that my auto-relogin code isn't quite working, I suspect that when an xml-rpc client 
> logs in with a callback URL, that callback URL is tested during the login process, before 
> login returns.  Is that true?

Yes, this is correct, in CbDispatchConnection.java:97
we do a ping("") to check availability.

> If that's the case, I'll have to spawn the relogin process into a new thread, because I'm 
> calling login from the thread that handles the callback, so it can't answer right away. It seems 
> to hang.

If this code is generic we are happy to integrate it into the xmlBlaster distribution.

best regards,

Marcel


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