Re: Speeding up rbd_stat() in libvirt

[Wido den Hollander <wido@42on.com>]

On 04-01-16 16:38, Jason Dillaman wrote:
> Short term, assuming there wouldn't be an objection from the libvirt community, I think spawning a thread pool and concurrently executing several rbd_stat calls concurrently would be the easiest and cleanest solution.  I wouldn't suggest trying to roll your own solution for retrieving image sizes for format 1 and 2 RBD images directly within libvirt.
> 

I'll ask in the libvirt community if they allow such a thing.

> Longer term, given this use case, perhaps it would make sense to add an async version of rbd_open.  The rbd_stat call itself just reads the data from memory initialized by rbd_open.  On the Jewel branch, librbd has had some major rework and image loading is asynchronous under the hood already.
> 

Hmm, that would be nice. In the callback I could call rbd_stat() and
populate the volume list within libvirt.

I would very much like to go that route since it saves me a lot of code
inside libvirt ;)

Wido