Path: utzoo!attcan!uunet!dg!rec
From: rec@dg.dg.com (Robert Cousins)
Newsgroups: comp.unix.questions
Subject: Re: fopen ( ..., "a" ) --- how does the "a" work?
Message-ID: <237@dg.dg.com>
Date: 11 Dec 89 15:41:08 GMT
References: <3250@hub.UUCP> <236@dg.dg.com> <3319@rti.UUCP>
Reply-To: uunet!dg!rec (Robert Cousins)
Organization: Data General, Westboro, MA.
Lines: 29

In article <3319@rti.UUCP> trt@rti.UUCP (Thomas Truscott) writes:
>> It is important to point out that use of "a" mode is some circumstances
>> will not work as anticipated.  ... [problems with NFS noted]
>
>> Had this been a stateful protocol ("append x bytes to file y") and multiple
>> requests were delivered, one could easily see a datafile with a bad
>> case of the "stutters."
>
>Except of course that stateful protocols invariably have "at most once"
>semantics.  Since it is stateful the protocol can easily
>detect and discard the duplicate requests.
>	Tom Truscott

It is true that there are a number ways in which NFS could have
been designed differently. However, the point is, fopen(..., "a")
does have some implications in an NFS environment which do
derive from the early design decision to use a stateless
protocol.
 
Question in general:  How could NFS have been designed (from
scratch) to be more closely representative of UNIX semantics
while keeping its "nice" features?  I think it is time to
have this discussion again. Maybe some new ideas will come up.

Robert Cousins
Dept. Mgr, Workstation Dev't.
Data General Corp.

Speaking for myself alone.