[libvirt-users] Determining domain job kind from job stats?

[Milan Zamazal]

Jiri Denemark <jdenemar at redhat.com> writes:

> On Fri, Feb 10, 2017 at 21:50:19 +0100, Milan Zamazal wrote:
>> Hi, is there a reliable way to find out to what kind of job does the
>> information returned from virDomainGetJobStats or provided in
>> VIR_DOMAIN_EVENT_ID_JOB_COMPLETED event callback belong to?
>
> No, libvirt expects that the caller knows what job it started. All jobs
> currently reported using virDomainGetJobStats API or
> VIR_DOMAIN_EVENT_ID_JOB_COMPLETED event are internally implemented as
> migration in QEMU driver (either to a file or to a network socket),
> which may confuse any heuristics for detecting the job type from the set
> of fields returned by libvirt.

I see, thank you for explanation.

> What is the problem you are trying to solve?

There are basically two problems:

- When the job completion callback is called, I need to distinguish what
  kind of job was it to perform the appropriate actions.  It would be
  easier if I knew the job type directly in the callback (no need to
  coordinate anything), but "external" job tracking is also possible.

- If I lost track of my jobs (e.g. because of a crash and restart), I'd
  like to find out whether a given VM is migrating.  Examining the job
  looked like a good candidate to get the information, but apparently
  it's not.  Again, I can probably arrange things to handle that, but to
  get the information directly from libvirt (not necessarily via job
  info) would be easier and more reliable.

Thanks,
Milan