Path: utzoo!utgpu!watmath!clyde!ima!think!barmar
From: barmar@think.COM (Barry Margolin)
Newsgroups: comp.protocols.nfs
Subject: Re: Suggestion for improved NFS monitoring
Keywords: retries, xids
Message-ID: <33151@think.UUCP>
Date: 8 Dec 88 17:40:38 GMT
References: <773@sequent.cs.qmc.ac.uk> <1287@stracs.cs.strath.ac.uk>
Sender: news@think.UUCP
Reply-To: barmar@kulla.think.com.UUCP (Barry Margolin)
Organization: Thinking Machines Corporation, Cambridge MA, USA
Lines: 23

In article <1287@stracs.cs.strath.ac.uk> jim@cs.strath.ac.uk writes:
>Worse, there doesn't appear to
>be any way that a client can ask the server to slow down, though an
>overloaded NFS client should not be as much of a problem as an overloaded
>server.

A client should never be overloaded.  NFS is based on RPC, so a server
never sends unrequested data.  If a client is overloaded it is because
it is sending requests faster than it can handle the responses.  This
might happen because it sends several requests in sequence, without
waiting for each to get a response, in an attempt to increase
throughput.  If it is sending too many requests this way, and the
server is much faster than the client, it may indeed get responses
back faster than it can handle.  But instead of asking the server to
slow down, the client can simply slow down its requests; instead of
asking for 10 blocks of a file at a time, it could ask for only five.


Barry Margolin
Thinking Machines Corp.

barmar@think.com
{uunet,harvard}!think!barmar