Re: Xenstore quota and driver domains

[Jürgen Groß <jgross@xxxxxxxx>]

On 04.06.20 10:16, Paul Durrant wrote:
> > -----Original Message-----
> > From: Jürgen Groß <jgross@xxxxxxxx>
> > Sent: 04 June 2020 09:11
> > To: paul@xxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx
> > Subject: Re: Xenstore quota and driver domains
> >
> > On 04.06.20 10:07, Paul Durrant wrote:
> > > > -----Original Message-----
> > > > From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of Jürgen 
> > > > Groß
> > > > Sent: 04 June 2020 06:03
> > > > To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> > > > Subject: Xenstore quota and driver domains
> > > >
> > > > A recent report on xen-users surfaced a problem we have with driver
> > > > domains in medium sized or large configuration: the driver domain can
> > > > easily hit the default Xenstore quota (in the report it was a driver
> > > > domain for disks which hit the quota when 15 domUs were active at the
> > > > same time).
> > > Which quota is hit? Node or watch?
> > Node.
> Ok. Since each individual backend is going to watch at least its frontend's 
> 'state' node then a watch quota of 128 is still probably going to be 
> restrictive for a global driver domain so this ought to be settable on a 
> per-domain basis as well as the node quota.
TBH I'd go with any quota to be settable via the new interface.

Currently we have:

- number of nodes
- max size of a node
- number of watches
- number of concurrent active transactions

and there might be more coming in the future.


Juergen