Re: [PATCH RFC 1/1] nfsd: Initial implementation of NFSv4 Courteous Server

[Chuck Lever III <chuck.lever@oracle.com>]

> On Jun 16, 2021, at 3:25 PM, Dai Ngo <dai.ngo@oracle.com> wrote:
> 
> On 6/16/21 9:32 AM, Chuck Lever III wrote:
>>> On Jun 16, 2021, at 12:02 PM, J. Bruce Fields <bfields@fieldses.org> wrote:
>>> 
>>> On Thu, Jun 03, 2021 at 02:14:38PM -0400, Dai Ngo wrote:
>>>> . instead of destroy the client anf all its state on conflict, only destroy
>>>> the state that is conflicted with the current request.
>>> The other todos I think have to be done before we merge, but this one I
>>> think can wait.
>> I agree on both points: this one can wait, but the others
>> should be done before merge.
> 
> yes, will do.
> 
>> 
>> 
>>>> . destroy the COURTESY_CLIENT either after a fixed period of time to release
>>>> resources or as reacting to memory pressure.
>>> I think we need something here, but it can be pretty simple.
>> We should work out a policy now.
>> 
>> A lower bound is good to have. Keep courtesy clients at least
>> this long. Average network partition length times two as a shot
>> in the dark. Or it could be N times the lease expiry time.
>> 
>> An upper bound is harder to guess at. Obviously these things
>> will go away when the server reboots. The laundromat could
>> handle this sooner. However using a shrinker might be nicer and
>> more Linux-y, keeping the clients as long as practical, without
>> the need for adding another administrative setting.
> 
> Can we start out with a simple 12 or 24 hours to accommodate long
> network outages for this phase?

Sure. Let's go with 24 hours.

Bill suggested adding a "clear_locks" like mechanism that could be
used to throw out all courteous clients at once. Maybe another
phase 2 project!


--
Chuck Lever