From: Neil Brown Subject: Re: [PATCH 003 of 4] Make RPC 'ping' requests fail more quickly. Date: Thu, 16 Nov 2006 14:20:47 +1100 Message-ID: <17755.55567.747018.295618@cse.unsw.edu.au> References: <20061024122646.4426.patches@notabene> <1061024024903.4760@suse.de> <1163610870.5691.177.camel@lade.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Olaf Kirch , Chuck Lever , nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1GkXo6-0007Ue-Jz for nfs@lists.sourceforge.net; Wed, 15 Nov 2006 19:20:54 -0800 Received: from cantor2.suse.de ([195.135.220.15] helo=mx2.suse.de) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1GkXo6-0000UB-Ii for nfs@lists.sourceforge.net; Wed, 15 Nov 2006 19:20:55 -0800 To: Trond Myklebust In-Reply-To: message from Trond Myklebust on Wednesday November 15 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net On Wednesday November 15, trond.myklebust@fys.uio.no wrote: > On Tue, 2006-10-24 at 12:49 +1000, NeilBrown wrote: > > Sometimes when an RPC client is created, an initial 'PING' is sent to > > the RPC/NULL procedure to make sure the server is running. > > This is always done as a 'soft' call so a major timeout will be fatal. > > > > We change semantics so that if portmap reports that the service does > > not exist, or if a ECONNREFUSED error is returned we abort early > > rather than persist for the full timeout. > > What if the server is in the process of booting? If the RPC layer > doesn't handle that case, then we will have to add a loop to sleep and > wait in the NLM client. What is the purpose of the PING? It seems to me that it is intended to allow a one-time soft-fail. e.g. it would be used when first mounting a filesystem. If the server isn't responding, then fail the mount, even if it is a hard mount. Once the PING succeeds we assume the server is genuine and all future requests follow whatever soft/hard/intr rules are given for the mount. If this is the case, then a PING should fail as soon as there seems to be a genuine justification for the failure, such as an rpcbind error. NeilBrown ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs