Re: [libvirt] A laundry list of "TODO" items for libvirt
On Thu, Aug 28, 2008 at 04:30:55PM +0100, Richard W.M. Jones wrote:
On Thu, Aug 28, 2008 at 10:58:34AM -0400, Cole Robinson wrote:
> Last month you had brought up the idea of a unified api call to
> lookup all domains, with a flag option to filter the lookup by
> domain state:
>
> https://www.redhat.com/archives/libvir-list/2008-July/msg00215.html
It's worth making clear that the key issue isn't the filtering, but
the fact that the virConnectListDomains & virDomainLookupByID calls
would be combined. This is a big saving in the remote case too
because it turns 1+N round-trips into 1 round-trip.
Virt-manager and virt-top both make these 1+N calls frequently (as in,
once a second, and once every 3 seconds respectively).
Yes, this is a huge performance win when talking to XenD since each
XenD RPC call to list domains is ~ 0.5-1 second or worse.
Also, if we use the __virDrvSupportsFeature call then we can
actually
emulate it in src/libvirt.c for drivers / libvirtd instances which
don't understand the new call. This means that applications can use
the new call immediately, with confidence that it will work for all
cases.
Good idea - that hadn't occurred to me - it'll be useful for talking to
old libvirtd instances at the very least - implementing the new style
for built-in drivers should be trivial already.
Daniel
--
|: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :|
|: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|