Size-Limited Bi-directional Remote Procedure Call On Remote Direct Memory Access Transports
draft-ietf-nfsv4-rpcrdma-bidirection-02

The information below is for an old version of the document
Document Type Active Internet-Draft (nfsv4 WG)
Last updated 2016-04-17 (latest revision 2016-04-08)
Stream IETF
Intended RFC status Proposed Standard
Formats plain text pdf html bibtex
Reviews
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state I-D Exists
Consensus Boilerplate Yes
Telechat date
Responsible AD (None)
Send notices to (None)
Network File System Version 4                                   C. Lever
Internet-Draft                                                    Oracle
Intended status: Standards Track                           April 8, 2016
Expires: October 10, 2016

   Size-Limited Bi-directional Remote Procedure Call On Remote Direct
                        Memory Access Transports
                draft-ietf-nfsv4-rpcrdma-bidirection-02

Abstract

   Recent minor versions of NFSv4 work best when ONC RPC transports can
   send ONC RPC transactions in both directions.  This document
   describes conventions that enable RPC-over-RDMA transport endpoints
   to interoperate when operation in both directions is necessary.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on October 10, 2016.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Lever                   Expires October 10, 2016                [Page 1]
Internet-Draft          RPC-over-RDMA Bidirection             April 2016

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Understanding RPC Direction . . . . . . . . . . . . . . .   2
     1.2.  Rationale For RPC-over-RDMA Bi-Direction  . . . . . . . .   4
     1.3.  Design Considerations . . . . . . . . . . . . . . . . . .   6
     1.4.  Requirements Language . . . . . . . . . . . . . . . . . .   8
   2.  Conventions For Backward Operation  . . . . . . . . . . . . .   8
     2.1.  Flow Control  . . . . . . . . . . . . . . . . . . . . . .   8
     2.2.  Managing Receive Buffers  . . . . . . . . . . . . . . . .   9
     2.3.  Backward Direction Retransmission . . . . . . . . . . . .  11
     2.4.  Backward Direction Message Size . . . . . . . . . . . . .  11
     2.5.  Sending A Backward Direction Call . . . . . . . . . . . .  12
     2.6.  Sending A Backward Direction Reply  . . . . . . . . . . .  12
   3.  Backward Direction Upper Layer Binding  . . . . . . . . . . .  13
   4.  Limits To This Approach . . . . . . . . . . . . . . . . . . .  13
     4.1.  Payload Size  . . . . . . . . . . . . . . . . . . . . . .  13
     4.2.  Preparedness To Handle Backward Requests  . . . . . . . .  13
     4.3.  Long Term . . . . . . . . . . . . . . . . . . . . . . . .  14
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  14
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .  15
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   The purpose of this document is to enable bi-directional RPC
   transactions on RPC-over-RDMA transports that do not already support
   backward direction operation.  The conventions described herein can
   be used with the RPC-over-RDMA Version One protocol without changes.
   Therefore this document does not update [I-D.ietf-nfsv4-rfc5666bis].

   Backward direction transactions enable the operation of NFSv4.1, and
   in particular pNFS, on RPC-over-RDMA.  Providing an Upper Layer
   Binding for NFSv4.x callback operations is outside the scope of this
   document.

1.1.  Understanding RPC Direction

   The ONC RPC protocol as described in [RFC5531] is fundamentally a
   message-passing protocol between one server and one or more clients.
   ONC RPC transactions are made up of two types of messages.

   A CALL message, or "Call", requests work.  A Call is designated by
   the value CALL in the message's msg_type field.  An arbitrary unique
   value is placed in the message's xid field.  A host that originates a
   Call is referred to in this document as a "Requester."
Show full document text