[Sheepdog] Some setattr/getattr strangeness

[Chris Webb]

MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp> writes:

> Chris Webb wrote:
>
> > Hi Kazutaka. Just double-checking, but is there a race here where the id is
> > allocated but the key isn't written yet, i.e. a getattr on another host
> > could see a value for the attribute but that value is an empty string
> > because the new object hasn't been written?
> 
> Yes, there is...  I believe this is the reason you got the empty
> attribute.  I'll fix it.
> 
> Should setattr without '-x' also work atomically?  For example,
> multiple hosts may send setattr against the same existing attribute at
> the same time?  Currently, this operation can cause replication
> inconsistency.

I don't rely on this myself at present, but it's probably the sort of thing
that would surprise other integrators in future, so I think I'd be tempted
to make them both atomic if that's not very difficult?

Best wishes,

Chris.