[Xen-devel] Re: Java support for Xen APIs

["Ray Kelm" <kelmray@xxxxxxxxx>]

Hmm. Looking a little deeper, I find that I'm not really using the new
Xen API calls, but in fact, the older xml-rpc interface. I guess I
have some work to do to get my code running using the correct calls.
After looking at the code in XendAPI.py, VM.unpause will end up
returning xen_api_success_void(), which will not be a nil. It is only
the older api that was returning None directly, which resulted in
<nil> in the xml-rpc response. My bad.

-Ray

On 3/29/07, Ray Kelm <kelmray@xxxxxxxxx> wrote:
> I'm sorry, I should have been more clear. Apache xml-rpc has support
> for vendor extensions, which violate the original xml-rpc spec. In
> order for them to be enabled, their client library negotiates with the
> server implementation, and only if both sides have extensions enabled
> does it support them. The expected situation is that if a non-apache
> client accesses an apache server, it won't ask for extensions, so the
> server will not use them. If an apache client accesses an non-apache
> server, the negotiation is ignored, so the client disables the
> extensions.
>
> One of those extensions is support for returning a null value (or
> python's None in this case) as <nil> or maybe <ex:nil>. The python
> xmlrpc code does this apparently by default, when you call a method
> that has no return value, for example, xend.domain.unpause.
>
> Here's some information about the extensions supported by apache's
> library. http://ws.apache.org/xmlrpc/extensions.html
>
> In the end, I was unable to get it to work because xend wasn't
> responding in a way that apache recognized, so it was disabling
> extensions. I had to add a custom handler for <nil> using a class
> based on TypeFactoryImpl, which solved the problem nicely.
>
> -Ray
>
> On 3/29/07, Anthony Liguori <anthony@xxxxxxxxxxxxx> wrote:
> > Ray Kelm wrote:
> > > I've had some success using the apache xml-rpc library to access xen
> > > with version 3.0.4. There were a few gotchas, such as having to enable
> > > extension support because xend was sending back nil as a result, which
> > > is only valid if extensions are enabled. Unfortunately, it appears
> > > that xend was not honoring the fact that extension support is
> > > negotiated.
> >
> > Extension support isn't negotiated (at least, not by any API I know of).
> >       Do you have a reference for this?
> >
> > Regards,
> >
> > Anthony Liguori
> >
> >
> > > It would be handy to have a packaged solution that exports a simple
> > > api for talking to xend, as building some of the control structures is
> > > a bit of a pain.
> > >
> > > -Ray
> > >
> > >
> > > On 3/29/07, Premjith Rayaroth <premjith.rayaroth@xxxxxxxxxx> wrote:
> > >> Hi,
> > >>
> > >> Is Java support available for Xen APIs. Can I use Java to make XML-RPC
> > >> calls to the Xen machines? I assume only 'C' and 'Python' are supported.
> > >> Is there any plan to support Java.
> > >>
> > >> Thanks
> > >> -Prem
> > >>
> > >> _______________________________________________
> > >> Xen-devel mailing list
> > >> Xen-devel@xxxxxxxxxxxxxxxxxxx
> > >> http://lists.xensource.com/xen-devel
> > >>
> >
> >
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