Subject: Re: [PATCH 6/9] sunrpc: close connection when a request is
 irretrievably lost.
From: Trond Myklebust <trond.myklebust@fys.uio.no>
To: Neil Brown <neilb@suse.de>
Cc: Chuck Lever <chuck.lever@oracle.com>,
        "J. Bruce Fields" <bfields@fieldses.org>, linux-nfs@vger.kernel.org
In-Reply-To: <20100204082354.0bf3b7e5@notabene.brown>
References: <20100203060657.12945.27293.stgit@notabene.brown>
	 <20100203063131.12945.34978.stgit@notabene.brown>
	 <4B699988.9000209@oracle.com>  <20100204082354.0bf3b7e5@notabene.brown>
Content-Type: text/plain; charset="UTF-8"
Date: Wed, 03 Feb 2010 17:20:10 -0500
Message-ID: <1265235610.5217.21.camel@localhost>
Sender: linux-nfs-owner@vger.kernel.org
MIME-Version: 1.0

On Thu, 2010-02-04 at 08:23 +1100, Neil Brown wrote: 
> On Wed, 03 Feb 2010 10:43:04 -0500
> Chuck Lever <chuck.lever@oracle.com> wrote:
> > 
> > I don't think dropping the connection will cause the client to 
> > retransmit sooner.  Clients I have encountered will reconnect and 
> > retransmit only after their retransmit timeout fires, never sooner.
> > 
> 
> I thought I had noticed the Linux client resending immediately, but it would
> have been a while ago, and I could easily be remembering wrongly.

It depends on who closes the connection.

The client assumes that if the _server_ closes the connection, then it
may be having resource congestion issues. In order to give the server
time to recover, the client will delay reconnecting for 3 seconds (with
an exponential back off).

If, on the other hand, the client was the one that initiated the
connection closure, then it will try to reconnect immediately.

Cheers
  Trond