[Libvirt-cim] [PATCH] [RFC] Transition back to connect_by_classname()

[Heidi Eckhart]

Dan Smith wrote:
> # HG changeset patch
> # User Dan Smith <danms at us.ibm.com>
> # Date 1195080791 28800
> # Node ID cfb48c67f1e611f10003a6c17ba458080f9d76f4
> # Parent  c9e977e820e99070f0c0c0397061229f7382ac7b
> [RFC] Transition back to connect_by_classname()
>
> Previously, we used the incoming reference for all operations to determine
> the URI to pass to libvirt during a connect operation.  For some reason,
> we transitioned away from that to a detection-based mechanism, which would
> not support multiple technologies to be managed from the provider
> simultaneously.
>
> I think that we have enough other infrastructure in place now that this is
> no longer a problem.  As a test, I offer this patch with a few key instances
> of lv_connect() replaced with connect_by_classname() for discussion.
>
> I have tested that enumeration of Xen_ComputerSystem, KVM_ComputerSystem,
> and CIM_ComputerSystem are exclusive, and do not return any duplicate
> results.
>   
I'm very sorry to tell you, that it does not work with sfcb.

[heidineu at localhost ~]$ wbemein 
http://localhost/root/virt:CIM_ComputerSystem
*
* wbemein: Cim: (1) CIM_ERR_FAILED: Unable to connect to hypervisor
*

while the following debug messages are given out:

misc_util.c(67): Connecting to libvirt with uri `xen'
misc_util.c(67): Connecting to libvirt with uri `qemu:///system'
misc_util.c(76): Connected to libvirt with uri `qemu:///system'

For me this looks like, that the provider has a problem with being 
called multiple times (in parallel), because one connection was 
established with success.
> Further, I have confirmed that resolving Xen_SystemDevice against a
> KVM_ComputerSystem instance does not work, and that no duplicate results
> are returned in the case of CIM_SystemDevice.
>
> If this looks okay to people (and wider testing supports my findings),
> I propose we start to convert uses of lv_connect() back to per-class
> connections until we encounter a problem.
>
> Comments welcome.
>   

-- 
Regards

Heidi Eckhart
Software Engineer
Linux Technology Center - Open Hypervisor

heidieck at linux.vnet.ibm.com

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