[AFS3-std] Standardization of GetCapabilties RPCs for AFS3 client and services

[Jeffrey Hutzelman]

On Sunday, February 26, 2006 01:06:09 AM -0500 Jeffrey Altman 
<jaltman@secure-endpoints.com> wrote:

> What I took away from that
> thread was a desire by cell administrators including yourself to prevent
> Windows AFS clients contacting your servers from obtaining AFS File
> Locks

That was never what I asked for.  I wanted the ability to configure clients 
to use the old behavior, and you had indicated you'd be removing that 
option in relatively short order.  My concern was about being forced into 
an impossible timescale for transition.



> When 1.6 ships the Windows clients are going to stop being broken with
> regards to locks.  If the Windows CIFS client asks for a lock, the AFS
> Cache Manager is going to request that lock.  This scares many
> administrators and they would prefer the existing behavior in which the
> Windows Cache Manager never requests an AFS File Lock unless the
> requested lock starts at offset 0 and the length of the locking range is
> greater than or equal to the file size.  These administrators want a
> means to control when the new behaviors kick in while at the same time
> having their users benefit from new user interfaces, support for 64-bit
> Windows platforms, and performance improvements.

Right.  I want that ability as a _client_ administrator, and I don't want 
you to take it away prematurely.  I have no desire as a server administator 
to tell clients not to get locks; that's a matter of client policy.  If I 
want, I can always modify my servers to ignore permissions and lock state 
and just let anyone get a lock.


> The only way that I know of that can be used to accommodate the needs of
> the administrators is to allow the servers to provide hints to the
> clients.  If you have an alternate proposal that will work, please
> describe it.

The key point is about allowing servers to provide information that can be 
used by a client in making a decision, rather than asserting a particular 
policy that clients are expected to blindly follow.

We had a very productive offline discussion today, which I think answered 
most of my concerns.  Later today I'll write up some of the details of that 
discussion, as well as some specific concerns that I still have.

-- Jeff