ISO 8571-2:1988/Amd 2:1993

Information processing systems — Open Systems Interconnection — File Transfer, Access and Management — Part 2: Virtual Filestore Definition — Amendment 2: Overlapped access

Extends the definitions given in ISO 8571 part 2 for an abstract model of the virtual filestore for describing files and filestores, sets of actions that may be used to manipulate the elements of this model, and the properties of individual files and associations to incorporate the concepts of overlapped access. The objective in introducing overlapped access is to allow more efficient access to structured files when a single initiator has a need to perform many reading and updating operations.

Systèmes de traitement de l'information — Interconnexion de systèmes ouverts — Transfert, accès et gestion de fichiers — Partie 2: Détermination du système de fichiers virtuel — Amendement 2: Chevauchement d'accès

General Information

• Status: Published
• Publication Date: 18-Aug-1993
• ICS: 35.100.70 - Application layer
• Technical Committee: ISO/IEC JTC 1 - Information technology
• Drafting Committee: ISO/IEC JTC 1 - Information technology
• Current Stage: 6060 - International Standard published
• Start Date: 19-Aug-1993
• Completion Date: 14-Feb-2026

Relations

• Amends: ISO 8571-2:1988 - Information processing systems — Open Systems Interconnection — File Transfer, Access and Management — Part 2: Virtual Filestore Definition
• Effective Date: 06-Jun-2022
• Child: ISO 8571-2:1988 - Information processing systems — Open Systems Interconnection — File Transfer, Access and Management — Part 2: Virtual Filestore Definition
• Effective Date: 15-Apr-2008

Overview

ISO 8571-2:1988/Amd 2:1993 is an important amendment to the international standard ISO 8571-2, titled Information Processing Systems - Open Systems Interconnection - File Transfer, Access and Management - Part 2: Virtual Filestore Definition. This amendment introduces the concept of overlapped access to the virtual filestore model, significantly enhancing the efficiency of file access operations in networked environments.

The standard, published by ISO, extends the original file and filestore abstract model by allowing multiple read and write operations to overlap during file access. This improves performance in scenarios where a single initiator performs numerous sequential reading and updating operations, reducing control overhead and supporting more efficient data transfer.

Key Topics

• Virtual Filestore Model Extension
  The amendment builds upon the existing abstract model for describing files and filestores, detailing how overlapped access can be integrated into the system without altering the fundamental definitions.

• Overlapped Access Concept

  • Consecutive Overlap: Allows queuing of read and write requests while a previous action is in progress, enabling multiple operations to be scheduled efficiently.
  • Concurrent Access: Enables simultaneous read and write data transfers in both directions, exploiting full-duplex communication paths to boost throughput.

• Serializability and Data Consistency
  While overlapped access improves performance, the amendment carefully addresses the resulting nondeterminism. It ensures that the final effect of overlapped operations matches that of serialized executions, maintaining service consistency and reliability.

• Activity Attributes for Overlapped Access
  New attributes such as current degree of overlap and vectors for access requests and processing states help manage and monitor overlapping file operations within the open regime of the filestore.

• File Access Actions Updates
  Modifications to standard file actions like Locate and Erase accommodate the behavior of overlapped reading and writing by tracking separate file access data units (FADUs) for concurrent operations.

Applications

• Networked File Transfer Systems
  Overlapped access facilitates more efficient file transfers over high-latency or bandwidth-constrained connections by enabling multiple file operations to be "in flight" simultaneously.

• Distributed File Management
  Systems managing structured files in distributed environments benefit from the reduced control overhead, allowing applications to perform rapid and concurrent read-write cycles effectively.

• Open Systems Interconnection (OSI) Environments
  ISO 8571-2 Amendment 2 aligns with OSI architecture principles, providing improved file transfer and access management capabilities within interoperable networked systems.

• Real-Time and High-Performance Computing
  Applications that require fast and frequent access to file data, such as streaming or database management, can leverage overlapped access to enhance throughput and responsiveness.

Related Standards

• ISO 8571 Series

  • Part 1: General Introduction
  • Part 3: File Service Definition
  • Part 4: File Protocol Specification
  • Part 5: Protocol Implementation Conformance Statement Proforma

• ISO/IEC JTC 1 Information Technology Standards
  The amendment is part of the broader set of standards developed by the ISO/IEC Joint Technical Committee 1 focused on Information Technology and Open Systems Interconnection.

• Open Systems Interconnection (OSI) Framework
  Related OSI standards provide the architectural and protocol foundations over which ISO 8571-2 operates, ensuring interoperability between systems in network environments.

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Keywords: ISO 8571-2, overlapped access, virtual filestore, file transfer, file access management, Open Systems Interconnection, FTAM, file operations, networked file systems, concurrent file access, file protocol, data consistency, file attributes.

This amendment ensures that information technology systems can achieve higher efficiency in file transfer and management while maintaining adherence to international best practices in open network communications.

Standards Content (Sample)

INTERNATIONAL
STANDARD 857 l-2
First edition
1988-10-01
AMENDMENT 2
1993-08- 15
Information processing Systems - Open Systems
Interconnection - File Transfer, Access and
Management -
Part2
Virtual Filestore Definiti on
AMENDMENT 2 : Over I apped access
Systkmes de traitement de I’information - Interconnexion de systkmes
ouverts - Transfer-t, acc& et gestion de fichiers -
Partie 2: Definition du Systeme de fichiers virtuel
AMENDEMENT 2 : Chevauchement d’accks
Reference number
ISO 8571~2:1988/Amd.2:1993 (E)

ISO 857%2:1988/Amd.2:1993 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International
Electrotechnical Commission) form the specialized System for worldwide
standardization. National bodies that are members of ISO or IEC participate in
the development of International Standards through technical committees
established by the respective organization to deal with particular fields of
technical activity. ISO and IEC technical committees collaborate in fields of
mutual interest. Other international organizations, governmental and non-
governmental, in liaison with ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint
technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the
joint technical committee are circulated to national bodies for voting. Publication
as an International Standard requires approval by at least 75 % of the national
bodies casting a vote.
Amendment 2 to International Standard ISO 8571-2:1988 was prepared by Joint
Technical Committee lSO/lEC JTC 1, Information technology.
ISO 8571 consists of the following Parts, under the general title Information
processing Systems - Open Systems Interconnection - File Transfer, Access and
Management:
- Part 7 : General htroduction
- Part 2 : Virtual Fjlestore Definition
- Part 3 : Fjie Service Definition
- Part 4 : File Protocol Specifkation
- Part 5 : Protocol Imp/ementatr”on Conformance Statement Proforma
0 iSO/IEC 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or by
any means, electronie or mechanical, including photocopying and microfilm, without
Permission in writing from the publisher.
ISO/IEC Copyright Office l Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ISO 857%2:1988/Amd.2:1993 (E)
Information processing Systems - Open Systems Interconnection - File
Transfer, Access and Management -
Part2:
Virtual Filestore Definition
AMENDMENT 2 : Overlapped access
oth8r BDT actions, subjed to restrictions; this is cakd
0 Introduction
consecutk overlap. Secondly, r8ad and writ8 actions tan
be p0rformd in parallel, so that both dir8ctions of data
transfer ar8 8xpioit8d at any one tim8. R8qu8sts ar8 th8n
Claus8 0 provides an introduction to this amendmnt lhe
tak8n from th8 queue whenever eith8r dir8cUon of transfer
text in thnS clause is not intended for inclusion in iS0 8571
becomes fr88. This is cakd concurrent acc8ss.
part2*
Th8 transfer of a Single FADU, sp8cifbd in a Single F-MAD
r8qu8st has the same IntsrpreWon as In ISO 8571. The
0.1 General
resuttant eff8ct on the virtual fiktore of a s8t of overlapped
requests using con~ecutive access shall b8 the same as
ISO 8571 part 2 defines an abstract model of the virtual
that of the equivaknt s8t of r8qu8stS issued in s8ri8s; the
filestore for describing files and filestores. Sets of actions
servic8 provid8d is seriaiizabie. lf concurrent acc8SS is
are defined that may be us8d to manipulate the 868ments of
u~8d th8n th8 resuitant effect of a s8t of write actions on the
this model, and the properties of individual fil8S and
ViftUd fiktore, is ak s8rialiZabk kklW8V8r, due t0 th8
associations are defined in terms of attributes.
nondeterminism introduced by the use of concurrent
access, it is also possible that in some USBS of the servk,
lndment extends these defi nitions to incorporate
This ame th8
the data transferred as a r8suk of a read action is not
concepts of overiapped acc8ss.
consistent with the current state of th8 file.
012 Rationale
1 Scope and field of application
The objective in introducing overlapped acc8ss is to allow
more eff ici8nt acc8~s to structured files when a Single
This ammdmnt makes no additions to clause 1.
initiator has a ne8d to Perform many reading and updating
operations; the serial nature of th8 current FTAM data
transfer servic8~ introduces a significant control overhead
if the FADUs are small. In this context, an FADU is small if
2 References
k tMISmiSSiOn tim8 iS COmparabk3 with the tinW t0 COmpl8t8
a confirm8d senk8 on the association (the association’s
This ammibnt makm no aMtions to Claus0 2.
round trii delay).
0.3 summary
3 Reference model definitions
Th
...