Re: [nfsv4] [FedFS] Meeting Minutes, 11/5/2009

[James Lentini <jlentini at netapp.com>]

On Fri, 6 Nov 2009, Nicolas Williams wrote:

> Should we have a notion of FSN/FSL soft and _hard_ TTLs?  Soft TTL
> expiration -> attempt to re-resolve.  Hard TTL expiration -> if can't
> resolve, then the junction returns an error.

The current TTL field is what you would describe as a "hard TTL". The 
question therefore is if a soft TTL field should be added. At a 
glance, it doesn't seem necessary since the fileservers are free to 
implement such a policy on their own. I'm concerned that adding an 
additional TTL field increases the complexity of the administration 
model. More knobs and dials increase the chance for a configuration 
error. I'd argue that the fileserver software is in the best position 
to make intelligent decisions about refreshing its FSN-to-FSL cache.