cvs commit: src/sys/nfsserver nfsrvcache.h

[Mohan Srinivasan]

--- Sam Leffler <sam at errno.com> wrote:

> > 
> > Fundamentally it doesn't, this change just pushes it out of the regime
> > where it's trivial to overflow.
> 
> Why is it hard to do a real fix?  Or is this a temporary bandaid?

Most NFS server that I am aware of will scale the duplicate request cache
based on the memory available (and we should probably do the same).

It is very easy to overflow a 64 entry duplicate request cache though, and
bumping it makes sense.

So, this is not a bandaid. The real fix is to use NFS/TCP, although even 
there, the duplicate request cache cannot be completely eliminated, because a 
non-idempotent request can be re-transmitted after a connection teardown
and re-establishment.

mohan