Remote Direct Memory Access - Connection Manager (RDMA-CM) Private Data for RPC-over-RDMA Version 1
draft-ietf-nfsv4-rpcrdma-cm-pvt-data-08

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00
• 01
• 02
• 03
• 04
• 05
• 06
• 07
• 08

Network File System Version 4                                   C. Lever
Internet-Draft                                                    Oracle
Updates: 8166 (if approved)                            February 21, 2020
Intended status: Standards Track
Expires: August 24, 2020

    RDMA Connection Manager Private Data For RPC-Over-RDMA Version 1
                draft-ietf-nfsv4-rpcrdma-cm-pvt-data-08

Abstract

   This document specifies the format of Remote Direct Memory Access -
   Connection Manager (RDMA-CM) Private Data exchanged between RPC-over-
   RDMA version 1 peers as part of establishing a connection.  The
   addition of the private data payload specified in this document is an
   optional extension that does not alter the RPC-over-RDMA version 1
   protocol.  This document updates RFC 8166.

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 https://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 August 24, 2020.

Copyright Notice

   Copyright (c) 2020 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
   (https://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

Lever                    Expires August 24, 2020                [Page 1]
Internet-Draft        RPC-Over-RDMA CM Private Data        February 2020

   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Advertised Transport Properties . . . . . . . . . . . . . . .   3
     3.1.  Inline Threshold Size . . . . . . . . . . . . . . . . . .   4
     3.2.  Remote Invalidation . . . . . . . . . . . . . . . . . . .   4
   4.  Private Data Message Format . . . . . . . . . . . . . . . . .   5
     4.1.  Using the R Field . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Send and Receive Size Values  . . . . . . . . . . . . . .   7
   5.  Interoperability Considerations . . . . . . . . . . . . . . .   7
     5.1.  Interoperability with RPC-over-RDMA Version 1
           Implementations . . . . . . . . . . . . . . . . . . . . .   8
     5.2.  Interoperability Amongst RDMA Transports  . . . . . . . .   8
   6.  Updating the Message Format . . . . . . . . . . . . . . . . .   8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  Guidance for Designated Experts . . . . . . . . . . . . .  10
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  12
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   The RPC-over-RDMA version 1 transport protocol [RFC8166] enables
   payload data transfer using Remote Direct Memory Access (RDMA) for
   upper-layer protocols based on Remote Procedure Calls (RPC)
   [RFC5531].  The terms "Remote Direct Memory Access" (RDMA) and
   "Direct Data Placement" (DDP) are introduced in [RFC5040].

   The two most immediate shortcomings of RPC-over-RDMA version 1 are:

   o  Setting up an RDMA data transfer (via RDMA Read or Write) can be
      costly.  The small default size of messages transmitted using RDMA
      Send forces the use of RDMA Read or Write operations even for
      relatively small messages and data payloads.
      The original specification of RPC-over-RDMA version 1 provided an
      out-of-band protocol for passing inline threshold values between
      connected peers [RFC5666].  However, [RFC8166] eliminated support
      for this protocol making it unavailable for this purpose.

Lever                    Expires August 24, 2020                [Page 2]
Internet-Draft        RPC-Over-RDMA CM Private Data        February 2020