Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!husc6!spdcc!ftp!corwin
From: corwin@ftp.COM (Walter Stickle)
Newsgroups: comp.protocols.nfs
Subject: Re: Interdrive or PC/NFS Connection Timeouts
Summary: InterDrive problem real, but fixed in next version.
Message-ID: <741@ftp.COM>
Date: 17 Oct 89 21:16:00 GMT
References: <6@softeng1.UUCP>
Reply-To: corwin@ftp.UUCP (Walter Stickle)
Organization: FTP Software, Inc.
Lines: 33

In article <6@softeng1.UUCP> zumbachl@softeng1.UUCP (Lyle Zumbach) writes:
>Both Sun's PC/NFS and FTP's Interdrive don't seem to handle
>network connection loss very well. It seems like there is
>a high chance of losing data (and not knowing about it) if you
>lose your network connection. Is this true? Shouldn't the user
>be presented with the Abort, Retry, Ignore message (DOS critical
>error handler?) ? Does the fact that NFS is a stateless protocol
>cause the problem?

Well, Since Geoff answered for PC/NFS, I'll just answer for
InterDrive.  While waiting for a transaction response, InterDrive uses
an adaptive retransmit algorhythim to retry for a configurable amount
of time.  In the case of a timout, the current version does return an
error.  The assumption was that most routines would check for error
returns, making the critical error handling a moderatly low priority.
It has become clear that this is a bad assumption, and that simply
returning an error is the *wrong* thing to do.

So... DOS critical error handling has been added to the next
release (currently under development), to allow the user the "Abort,
Retry, Ignore" options.  Like the current version, the time before the
timout will be configurable, but no error will be returned (and no
data lost) unless the user so chooses.

	-wls
-----------------------------------------------------------------------------
Walter L. Stickle	   corwin@vax.ftp.com                  ..!ftp!corwin
Hacking Networking for FTP Software,	        Wakefield MA  (617)-246-0900
      ...and playing Guitar until my fingers fall off...          ext. 277
------------------------------------------------------------------------------- 
Walter L. Stickle	   corwin@vax.ftp.com                  ..!ftp!corwin
Hacking Networking for FTP Software,	        Wakefield MA  (617)-246-0900
      ...and playing Guitar until my fingers fall off...          ext. 277