IETF Logo Mail Archive

Re: [nfsv4] persistent sessions and compound atomicity

David Noveck <davenoveck@gmail.com> Fri, 11 December 2020 11:12 UTC

Return-Path: <davenoveck@gmail.com>
X-Original-To: nfsv4@ietfa.amsl.com
Delivered-To: nfsv4@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id DAA7D3A0A42 for <nfsv4@ietfa.amsl.com>; Fri, 11 Dec 2020 03:12:48 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.097
X-Spam-Level:
X-Spam-Status: No, score=-2.097 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rI_P3b8r_ASx for <nfsv4@ietfa.amsl.com>; Fri, 11 Dec 2020 03:12:47 -0800 (PST)
Received: from mail-qk1-x72d.google.com (mail-qk1-x72d.google.com [IPv6:2607:f8b0:4864:20::72d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 00BD83A0A3D for <nfsv4@ietf.org>; Fri, 11 Dec 2020 03:12:46 -0800 (PST)
Received: by mail-qk1-x72d.google.com with SMTP id z188so7972626qke.9 for <nfsv4@ietf.org>; Fri, 11 Dec 2020 03:12:46 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=brzdO8YhGfFHpRTDlEEadtaULYno8gdCItil9TwC1eg=; b=TDctzQbjqMxJ+ajinhnQ9OnJtSrdM5+dtf/JlCWxMcZjAWU0WSErG3uhgqMCnPnrlb 02TZXaF14ENrqJrXIl6nvAWfe/JjY1hK7znnndLamQKd8kc7ARI3LCbzRJbhKmJ+jbXg 0NJu4FSnej/mUahplbXxX9HyZ7qP5u+vXoQwk6JVyN8d+XZc3XNe5NPFo6BjPCTYyNZv Wob5C7gNNy39FTnjZ9/AiKDVO9AJGtJZIbH/0ukrbr4QjmCyxNMd/H6svzZ57FOnOfsi 4u6biZ4uuH6ahvqTczpKw9QEP/gwVLvgDzvJFVlM068QPT2r1rMwK90dbPTOWF0NT+/I AF3w==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=brzdO8YhGfFHpRTDlEEadtaULYno8gdCItil9TwC1eg=; b=RNc49mDLlRFq2KIOZWEqwnTmkjc1T9lvgY6ZpHOTPqupSkxUPcwwgFXvZlpscHQ6xX xzji7RlNqDgf4h1uFaK+u1kZ0NrxxVHKc9gobRPipgU4Q+/2n6iVkh+Mguc10asNsyee nj6sK9qP5nyxA5X0XranRTbo6v2S1/Z1zG0Hdu28ryDygQUgDo7n5ehO8T0ZGDx8d5er 5DbsvTyArRq1DS/I5zwEWicxMrV86SEiSV4slO6XVQicxYm9NEfZGxyx+CISsf2IEvBb JmsJ2DzPGGxJEGxCbn7NIGCBuNO6Z9rqtx4DQZaqlZpXep3KjLgSp6s+BOTuzs3UZGVI QCSQ==
X-Gm-Message-State: AOAM532zUXwgknj2YH4Y+e2hCnJgJjYvzxpfYCTR3tl73mu4JK5Cbt/7 +Ca3eLNhtZ9FqS6urjNjkG69h6H7Hl+htAw1bQk=
X-Google-Smtp-Source: ABdhPJwbH41t1Ux8BUige4d51L1u1+6s0k81Ye3aZ9l8bFKeIRY0P63S0gbur07yun2W1MryhOC6HWBFNzl6swNtio8=
X-Received: by 2002:a37:7085:: with SMTP id l127mr15274098qkc.106.1607685165908; Fri, 11 Dec 2020 03:12:45 -0800 (PST)
MIME-Version: 1.0
References: <20201209002639.GC16661@fieldses.org> <93d4e52e-23e6-cf5f-4b0f-50060f4c6151@talpey.com> <20201209144927.GB23889@fieldses.org> <2d94c517-04ba-75b0-9583-4b7eb4aa8ced@talpey.com> <YQXPR0101MB096883BD0B2EBF66D12FC732DDCC0@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM> <20201209225944.GC24283@fieldses.org> <CADaq8jdYyigfkHDbAdk7uARzdSsoNHdPZdUJjPMka5_4tZ6C6Q@mail.gmail.com> <7246cdd69b6e53fee4b657d9c51a973208c96cbf.camel@gmail.com>
In-Reply-To: <7246cdd69b6e53fee4b657d9c51a973208c96cbf.camel@gmail.com>
From: David Noveck <davenoveck@gmail.com>
Date: Fri, 11 Dec 2020 06:12:35 -0500
Message-ID: <CADaq8je2hgE6EnjR38R4rqP8SHzyx-vX+Wx3bEMvKt0t+AfqhA@mail.gmail.com>
To: Trond Myklebust <trondmy@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>, Tom Talpey <tom@talpey.com>, Rick Macklem <rmacklem@uoguelph.ca>, "nfsv4@ietf.org" <nfsv4@ietf.org>
Content-Type: multipart/alternative; boundary="00000000000039898005b62e5fa5"
Archived-At: <https://mailarchive.ietf.org/arch/msg/nfsv4/1EMDS6JicWo49mp4ESZTfZcS5qk>
Subject: Re: [nfsv4] persistent sessions and compound atomicity
X-BeenThere: nfsv4@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: NFSv4 Working Group <nfsv4.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/nfsv4>, <mailto:nfsv4-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/nfsv4/>
List-Post: <mailto:nfsv4@ietf.org>
List-Help: <mailto:nfsv4-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/nfsv4>, <mailto:nfsv4-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 11 Dec 2020 11:12:49 -0000

On Thu, Dec 10, 2020, 9:23 PM Trond Myklebust <trondmy@gmail.com> wrote:



> in Section 2.10.6.5 of RFC5661, there is the following snippet:
>

Deleted snippet about making the execution of a COMPOUND a transaction.

>
>
> Why shouldn't a client implementer reading the above be able to conclude
> that a NFS4ERR_DEADSESSION error implies that the operation failed with no
> side-effects?
>

No reason at all.  The problem is that requiring the server to implement
COMPOUNDs as atomic transactions if it implements persistent sessions has
no real justification and probably cannot be implemented.

Also I don't think it is right for the sever to send DEADSESSION since the
persistent session is not dead.  I still like DELAY which Tom thinks is the
spawn of the devil, but feel that if the server reboots, SERVERFAULT is
justified for ops abandoned because of that.

Maybe we need an nfsv4 error with error code 666, even if DELAY is not it.
Could be a subject for an I-D to be submitted 4/1/2021😊

> --
>
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trond.myklebust@hammerspace.com <trond.myklebust@primarydata.com>
>
>
>
>

v2.23.0 | Report a Bug | By Email