Re: Re: Can I regist two instance providers for a same CIM class?

An addition big problem I see with that is how would deletes of
obsolete instances happen? in theory the vendors providers should be
tracking their own instances and deleting obsolete ones as needed
however I doubt most of them are currently keeping track of this
information. i would almost be willing to bet most of them just delete
which ever ones they don't have current data on because its easier and
more efficient in terms of ram to enumerate the instance names and
tick them off the list as it updates then delete all of the remaining
instances it hasn't accounted for.

but while this might be an interesting idea its fraught with potential
pit falls, and It would require all current providers to be rewritten
to comply with the change in the design. So for now I still think the
proxy method would be the most realistic to develop within a
reasonable time span.

however the idea of multiple provides being used to populate one class
is an interesting idea for a long term development project for a
future version.


On Tue, Apr 26, 2011 at 1:55 PM, Kirk Augustin <[email protected]> wrote:
> Oh it could work that way.
> Whether or not is might be better I don't know.
> But the point is it is currently not the way it is expected to work.
> In general vendors tend to always extend the functionality, so must
> subclassed.
> For example, if they are providing a diagnostic of some sort, if it is
> short, they can just just have a property that the provider knows it has to
> run the diagnostic every time the property is accessed.  They then only
> create a method if a parameter has to be passed in.  While other vendors
> always create methods, whether it needs parameters or not.
> But there may be many other ways it could work.
> To allow a list of providers for a single class would require more
> cooperation between vendors than now exists.
>
> Kirk Augustin
> 11821 NW McNamee Rd
> Portland, OR 97231
>
> ________________________________
> From: Edward Shober <[email protected]>
> To: Kirk Augustin <[email protected]>; huruifeng
> <[email protected]>; Paul Robert Marino <[email protected]>
> Cc: "Sampige, Sahana Prabhakar (R&DBangalore)" <[email protected]>;
> "[email protected]" <[email protected]>
> Sent: Tue, April 26, 2011 10:34:01 AM
> Subject: RE: Re: Can I regist two instance providers for a same CIM class?
>
> This is all theoretical, but each instance of the class should be
> distinguishable
> by a set of keys. So, if you want to set properties of a particular device
> you
> must send the key values as well. Providers must ignore operations on
> instances
> that don't match the key values of the devices that they're responsible for.
> The CIMOM would call all providers registered for a particular class and
> each
> would respond with the instances that they have. Of course, if vendors
> extend
> the functionality of classes they must subclass.
>
> I guess my point is that, this may not be the way it works, but I don't see
> why
> it couldn't work this way.
>
> ________________________________________
> From: Kirk Augustin [[email protected]]
> Sent: Tuesday, April 26, 2011 11:07 AM
> To: Edward Shober; huruifeng; Paul Robert Marino
> Cc: Sampige, Sahana Prabhakar (R&DBangalore); [email protected]
> Subject: Re: Re: Can I regist two instance providers for a same CIM class?
>
> Yes, each vendor is supposed to subclass with their company or product name
> appended to the class.
> Otherwise if you wanted to configure or set properties of a particular
> device, you would end up sending it to all of the devices of that class,
> when you really meant to only set the one brand device.
> Typically each vendor uses different hardware/software features, so requires
> its own provider, and therefore own subclass.
> If you don't subclass, then how would the CIMOM know which provider to call?
>
> Kirk Augustin
> 11821 NW McNamee Rd
> Portland, OR 97231
>
>
> ________________________________
> From: Edward Shober <[email protected]>
> To: huruifeng <[email protected]>; Paul Robert Marino
> <[email protected]>; Kirk Augustin <[email protected]>
> Cc: "Sampige, Sahana Prabhakar (R&DBangalore)" <[email protected]>;
> "[email protected]" <[email protected]>
> Sent: Tue, April 26, 2011 8:38:55 AM
> Subject: RE: Re: Can I regist two instance providers for a same CIM class?
>
> I'm not sure what Huruifeng is trying to do but it seems like it should
> be important for multiple providers to be able to be registered for the
> same class. What about multiple PCI devices from different vendors
> for example? Shouldn't each vendor be able to register their provider
> with the CIMOM so that they can each serve up the appropriate
> instances of PCIDevice for their specific devices?
>
> I don't see why the CIMOM can't have a list of providers to be queried
> for each class. Does each vendor have to subclass PCIDevice or can
> they each register as an instance provider for PCIDevice?
>
> ________________________________
> From: huruifeng [[email protected]<mailto:[email protected]>]
> Sent: Tuesday, April 26, 2011 12:41 AM
> To: Paul Robert Marino; Kirk Augustin
> Cc: Sampige, Sahana Prabhakar (R&DBangalore);
> [email protected]<mailto:[email protected]>
> Subject: Re: Re: Can I regist two instance providers for a same CIM class?
>
> Hi Paul:
> Thank you for your idea.It is a way to resolve my problem,but when I have a
> lot of third-party providers,writting proxy providers will be a big job.
>
> Regards
> 2011-04-26
> ________________________________
> huruifeng
> ________________________________
> 浠朵汉锛 Paul Robert Marino
> 堕达 2011-04-26  14:15:17
> 朵欢浜猴 Kirk Augustin
> 锛 huruifeng; Sampige, Sahana Prabhakar (R&DBangalore);
> [email protected]<mailto:[email protected]>
> 涓婚锛 Re: Can I regist two instance providers for a same CIM class?
> The simple answer is if you want two different c or java based providers to
> provide information to one or multiple instances of the same class create a
> proxy provider which gathers information from both and consolidates it into
> specific instances prior to handing the information off to open Pegasus or
> any other WBEM server API.
>
>
> On 4/25/2011 11:40 PM, Kirk Augustin wrote:
> Hi Huruifeng,
>
> It does not matter what kind of provider you might want to try having 2 of,
> it won't work.
> If it could, it would be ambiguous.
> When you register the 2nd provider, for the same purpose, it will over write
> the first.
> I am not familiar with Small Footprint CIM Broker (SFCB), but it would make
> no sense for it allow 2 providers for the same class and purpose.
> I have not actually tried to have a separate provider for say instances and
> methods, because there would be no reason to.
> A method provider would also need to know about instances as well, so it is
> hard to see how it would be useful to separate them.
> Nothing is gained by having more providers than the minimal necessary.
> Often it is easiest to use one provider for many, many classes.
> The provider is told what class it is being queried on, so there is no
> problem having fewer providers.
> Think of each provider as an interface to a database.
> You would not want a provider for each table in a database, but just one for
> the entire database.
> You don't need another provider until you have a different database to also
> be able to connect to.
>
> Kirk Augustin
> 11821 NW McNamee Rd
> Portland, OR 97231
>
>
> ________________________________
> From: huruifeng
> <[email protected]<mailto:[email protected]>><mailto:[email protected]<mailto:[email protected]>>
> To: "Sampige, Sahana Prabhakar (R&D Bangalore)"
> <[email protected]<mailto:[email protected]>><mailto:[email protected]<mailto:[email protected]>>;
> "[email protected]<mailto:[email protected]>"<mailto:[email protected]<mailto:[email protected]>>
> <[email protected]<mailto:[email protected]>><mailto:[email protected]<mailto:[email protected]>>
> Sent: Mon, April 25, 2011 8:03:27 PM
> Subject: Re: RE: Can I regist two instance providers for a same CIM class?
>
> Hi Sahana:
> Here "two providers" you mean two instance providers?
> Now I hava two indication providers for CIM_AlertIndication,can I regist
> both of them like sfcb does?
> And what about a instance provider and a method provider both for
> CIM_ComputerSystem?
>
> Regards
>
> 2011-04-26
> ________________________________
> huruifeng
> ________________________________
> 浠朵汉锛 Sampige, Sahana Prabhakar (R&D Bangalore)
> 堕达 2011-04-25  17:53:17
> 朵欢浜猴 huruifeng;
> [email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>
> 锛
> 涓婚锛 RE: Can I regist two instance providers for a same CIM class?
> Hi Huruifeng,
> You cannot register two providers for the same CIM class. But you could
> register one provider each for the CIM class hierarchy. When you enumerate
> the base class for example CIM_ManagedElement, instances for
> CIM_ManagedElement and its sub class like CIM_LogicalElement, CIM_Processor
> etc, will be returned.
> Rgds,
> Sahana
>
> From: huruifeng [mailto:[email protected]<mailto:[email protected]>]
> Sent: Monday, April 25, 2011 3:05 PM
> To:
> [email protected]<mailto:[email protected]><mailto:[email protected]<mailto:[email protected]>>
> Subject: Can I regist two instance providers for a same CIM class?
>
> Hi:
> Can I regist two instance providers for a same CIM class?
> If it is possible, which provider will be called when a getInstance request
> is recieved?
>
> Regards
>
> 2011-04-25
> ________________________________
> huruifeng
>
>
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