[libvirt] [PATCH v2] qemu: Introduce state_lock_timeout to qemu.conf

[Michal Privoznik]

On 08/27/2018 04:29 PM, John Ferlan wrote:
> 
> 
> On 08/27/2018 09:29 AM, Michal Prívozník wrote:
>> On 08/27/2018 12:57 PM, Yi Wang wrote:
>>> When doing some job holding state lock for a long time,
>>> we may come across error:
>>> "Timed out during operation: cannot acquire state change lock"
>>> Well, sometimes it's not a problem and users wanner continue
> 
> s/wanner/want to/
> 
> or "prefer to"...  Perhaps users is too vague - this essentially sets
> the "default timeout policy" for everyone. Setting it too short could be
> dangerous considering it's impact.
> 
> If "a user" wanted or preferred to wait longer than the default job
> timeout for a specific command, then we'd need to add some option for
> various commands/API's that allowed setting a unique timeout value for a
> specific job.
> 
> Another thought would be to have an API that allowed changing the
> timeout programmatically. Of course there's the admin interface that is
> another area to consider altering since you're adjusting a configuration
> value like this.

If anything, this is a job for virt-admin. I don't think we need an API
that would live next to virDomainDeviceUpdate() for instance. We don't
have one for max_jobs, nor for lock_manager, ... In fact, I don't think
we have any API to change anything from qemu.conf.

Michal