maas-devel team mailing list archive

[Julian Edwards <julian.edwards@xxxxxxxxxxxxx>]

On Wednesday 30 Apr 2014 11:24:27 Jeroen Vermeulen wrote:
> On 04/30/2014 10:24 AM, Raphaël Badin wrote:
> >> I am left wondering if this is anything to do with Django's useless
> >> default DB isolation level?
> 
> Yes, it is.  And Django designed its house on top of that foundation, so
> we change it at our peril.
> 
> > Although AFAIK Django doesn't support optimistic locking, there is
> > support —since Django 1.4— for pessimistic locking which I think is what
> > we should be explicitly using here to protect such a critical code path
> > (https://docs.djangoproject.com/en/dev/ref/models/querysets/#select-for-up
> > date).
> That would do it.  We'd want to avoid blocking on it though, so we'd
> need to pass “nowait” and back off to a second choice if the lock failed.

Why can't we block with a timeout, like LP?