Re: [vdsm] VDSM API/clientIF instance design issue
On 05/30/2012 11:01 PM, Dan Kenigsberg wrote:
On Wed, May 30, 2012 at 10:49:29PM +0800, Mark Wu wrote:
> Hi Guys,
>
> Recently, I has been working on integrate MOM into VDSM. MOM needs
> to use VDSM API to interact with it. But currently, it requires the
> instance of clientIF to use vdsm API. Passing clientIF to MOM is
> not a good choice since it's a vdsm internal object. So I try to
> remove the parameter 'cif' from the interface definition and change
> to access the globally unique clientIF instance in API.py.
Please remind me - why don't we continue to pass the clientIF instance,
even if it means mentioning it each and every time an API.py object is
created? It may be annoying (and thus serve as a reminder that we should
probably retire much of clientIF...), but it should work.
In the old MOM integration patch, I passed the clientIF instance to MOM
by the following method:
vdsmInterface.setConnection(self._cif)
Here's your comments on the patch:
"_cif is not the proper API to interact with Vdsm. API.py is. Please
change MOM to conform to this, if possible.
I think that mom should receive an API object (even API.Global()!) that
it needs for its operation. Even passing BindingXMLRPC() object is more
APIish than the internal clientIF object."
So I try to remove cif from API definition to make MOM can call the VDSM
API without having clientIF.
> To get the instance of clientIF, I add a decorator to clientIF
to
> change it into singleton. Actually, clientIF has been working as a
> global single instance already. We just don't have an interface to
> get it and so passing it as parameter instead. I think using
> singleton to get the instance of clientIF is more clean.
>
> Dan and Saggi already gave some comments in
> http://gerrit.ovirt.org/#change,4839 Thanks for the reviewing! But
> I think we need more discussion on it, so I post it here because
> gerrit is not the appropriate to discuss a design issue.
>
> Thanks !
> Mark.
>