Requirements for Archiving IETF Email Lists and for Providing Web-Based Browsing and Searching
RFC 6778

Internet Engineering Task Force (IETF)                         R. Sparks
Request for Comments: 6778                                       Tekelec
Category: Informational                                     October 2012
ISSN: 2070-1721

              Requirements for Archiving IETF Email Lists
           and for Providing Web-Based Browsing and Searching

Abstract

   The IETF makes heavy use of email lists to conduct its work.
   Participants frequently need to search and browse the archives of
   these lists and have asked for improved search capabilities.  The
   current archive mechanism could also be made more efficient.  This
   memo captures the requirements for improved email list archiving and
   searching systems.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6778.

Copyright Notice

   Copyright (c) 2012 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.

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Table of Contents

   1. Introduction ....................................................2
   2. List Search and Archive Requirements ............................3
      2.1. Search and Browsing ........................................3
      2.2. Archiving Active Lists .....................................5
      2.3. Importing Messages from Other Archives .....................5
      2.4. Exporting Messages from the Archives .......................5
      2.5. Redundancy .................................................6
      2.6. Archive Administration .....................................6
      2.7. Transition Requirements ....................................7
   3. Internationalized Address Considerations ........................7
   4. IMAP Access .....................................................7
   5. Security Considerations .........................................7
   6. Acknowledgements ................................................7
   7. Informative References ..........................................8

1.  Introduction

   The IETF makes heavy use of email lists to conduct its work.
   Participants frequently need to search the archives of these lists
   and have asked for improved search capabilities, particularly when
   the search needs to cover a large period of time or cross several
   lists.  For instance, document editors, shepherds, working group
   chairs, and area directors may need to review all discussion of a
   particular draft.  That discussion may be spread across the working
   group list, one or more directorate lists, and the IETF general list.
   Occasionally, work impacts multiple groups, possibly in different
   areas, and the search must cover additional working group lists.

   The current tools for performing these searches require several
   manually coordinated steps, which are error prone.  Without a local
   copy of the archive (which may not be complete), searching most
   working group lists requires brute force effort, aided possibly by
   web search engines.

   More advanced search capabilities have been constructed for a limited
   subset of the available lists and are exposed in the "Email Archives
   Quick Search" section of the main IETF website.  While these tools
   are of great assistance, there is still significant need for
   improvement.

   The current archive mechanism could also be made more efficient.  The
   current practices involve duplicate stores (for the web and ftp
   interfaces), which impact storage and replication and are subject to
   inconsistency.

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RFC 6778         List Archiving and Search Requirements     October 2012

   This memo captures the requirements for improved email list archiving
   and searching systems.

2.  List Search and Archive Requirements

2.1.  Search and Browsing

   o  The system must provide a web interface for searching and browsing
      archived messages.

   o  The system must allow browsing the entire archive of a given list
      by thread or by date.

   o  The system must allow browsing the results of a search by thread
      or by date.

         Both threading based on Message-Id/References/In-Reply-To and
         threading based on same subject line (modulo short prefixes
         like re: and fwd:) should be taken into account.

   o  The system must allow searching across any subset of the archived
      lists (one list, a selection of lists, or all lists).

   o  The system must allow searching of any combination (using AND, OR,
      and NOT operators) of the following attributes.  Richer search
      capabilities are highly desirable.

      -  string occurring in sender name or email address

      -  date range

      -  string occurring in Subject

      -  string occurring in message body

      -  string occurring in message header (in particular, exact match
         of Message-Id)

            For instance, it would be nice to search the entire archive
            for instances of a message with a given Message-ID with a
            URL like <http://datatracker.ietf.org/mlarchive/
            msg?id=4EA6E023.6010603@example.com>

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RFC 6778         List Archiving and Search Requirements     October 2012

   o  Individual messages must be representable by a long-term stable
      URI that can be shared between users.  That is, the URI must be
      suitable for reference in an email message.

      -  It would be preferable for that URI to appear in an Archived-At
         header field in the message [RFC5064].

   o  Searches should be representable by a URI that can be shared
      between users.

      -  Such URIs should be long-term stable.

      -  The search may be re-executed when the URI is referenced.  It
         is acceptable for the same URI to produce different results if
         accessed at different times or by different people (for
         example, by reflecting additional messages that may match the
         search criteria or reflecting changes in access authorization
         to lists with restricted archives).

   o  When the system requires credentials, it must use the
      datatracker's authentication system.

      -  While the vast majority of archived lists have an open access
         policy, some archived lists have restricted archives.

      -  The system must not require credentials for browsing or
         searching lists with open archives.  (But it is acceptable for
         a user to browse or search such lists while logged in.)

      -  The system must make it possible to limit access to a
         restricted archive based on login credentials.

      -  Messages from restricted archives must be distinguishable from
         messages from unrestricted archives in any search results.

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2.2.  Archiving Active Lists

   o  The archive system must accept messages handled by various mail
      list manager packages.

      -  Lists hosted on the IETF systems are served by Mailman
         [Mailman].

      -  Lists hosted at other organizations may use other packages.

         *  The archive system must accept messages through subscribing
            to such an external list.

         *  The archive system may support other mechanisms for
            accepting messages into the archive.

2.3.  Importing Messages from Other Archives

   Lists hosted at other systems are sometimes moved to the IETF
   servers, and their archive is moved with them.  The archiving system
   must be able to import these archives.

   o  At a minimum, the archive system must be able to import mbox
      formatted archives [RFC4155] [Mbox].

   o  The archive system should be able to import Maildir and Maildir-
      like (the key characteristic being one-message-per-file) formatted
      archives [Maildir].

   o  It is acceptable to use a separate utility to convert between
      these formats before import, as long as the conversion is
      lossless.

2.4.  Exporting Messages from the Archives

   The archive system must allow both users and administrators to export
   messages.

   o  The archive system must support exporting messages in the mbox
      format.

   o  The archive system should support exporting messages in the
      Maildir format.

   o  The archive system must support exporting the entire archive of a
      given list.

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RFC 6778         List Archiving and Search Requirements     October 2012

   o  The archive system must support exporting all messages from a
      given list within a given date range.

   o  The archive system should allow exporting the results of any
      supported search query.

2.5.  Redundancy

   o  The systems must facilitate providing archive, search, and browse
      functions through geographically distributed servers.

      -  The systems must support a single active and single standby
         server.  This reflects the current operating configuration and
         is expected to be the initial deployment model.

      -  The systems should support a single active and multiple standby
         servers.

      -  The systems should support multiple active servers for the
         search and browse functions.  Support for multiple active
         archive servers is not a requirement.

      -  The amount of traffic generated to ensure data replication
         between servers should be on the order of the size of any new/
         changed messages in the archives.

         *  It is acceptable for replication to be part of the archival
            system itself (such as using the replication mechanisms from
            an underlying database).

         *  It is acceptable to rely on replication of the underlying
            filesystem objects (using rsync of one or more directory
            trees, for example), but only if the objects in the
            underlying filesystem are formatted such that the size of
            the replication data is on the order of the size of any new/
            changed messages in the archives.

2.6.  Archive Administration

   o  The archive system must support adding and removing lists to be
      archived.

   o  The system must allow the administrator to add messages to and
      delete messages from an archived list.  The system should log such
      actions.

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2.7.  Transition Requirements

   There are many existing archived messages containing embedded links
   into the existing MHonArc [MHonArc] mail archive.  These links must
   continue to work, but they should reach the message as archived in
   the new system.

3.  Internationalized Address Considerations

   The archive and search functions should anticipate internationalized
   email addresses as discussed in the following three documents --
   [RFC6531], [RFC6532], and [IMAP-UTF8].  There is no firm requirement
   at this time.

4.  IMAP Access

   Requirements for allowing access to the archives using IMAP are
   captured in [IMAP-ARCH].  The archive system must anticipate
   integrating with a system that provides IMAP access.

5.  Security Considerations

   Creating a new tool for searching and archiving IETF email lists does
   not affect the security of the Internet in any significant fashion.

   Searching can be I/O and CPU intensive.  The implementors of this
   tool should consider the potential for maliciously crafted searches
   attempting to consume all available resources.  Similarly, the
   implementors should consider the potential for denial-of-service
   attacks through making many connections to the browsing system or
   rapid navigating within it.

   Preserving the integrity of the archives is important.  The
   implementors should ensure that administrative access is
   appropriately authenticated, and that message paths into the archive
   are appropriately configured to avoid unauthorized message insertion.

6.  Acknowledgements

   The Tools Development team provided input into the initial
   brainstorm.  Text suggestions from Alexey Melnikov, Pete Resnick, S.
   Moonesamy, Francis Dupont, and Murray Kucherawy have been
   incorporated.

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7.  Informative References

   [IMAP-ARCH]  Sparks, R., "IMAP Access to IETF Email List Archives",
                Work in Progress, August 2012.

   [IMAP-UTF8]  Resnick, P., Ed., Newman, C., Ed., and S. Shen, Ed.,
                "IMAP Support for UTF-8", Work in Progress,
                October 2012.

   [Maildir]    "Maildir", <http://en.wikipedia.org/w/
                index.php?title=Maildir&oldid=503288041>.

   [Mailman]    "Mailman", <http://www.list.org/>.

   [Mbox]       "mbox", <http://en.wikipedia.org/w/
                index.php?title=Mbox&oldid=515402275>.

   [MHonArc]    "MHonArc", <http://www.mhonarc.org/>.

   [RFC4155]    Hall, E., "The application/mbox Media Type", RFC 4155,
                September 2005.

   [RFC5064]    Duerst, M., "The Archived-At Message Header Field",
                RFC 5064, December 2007.

   [RFC6531]    Yao, J. and W. Mao, "SMTP Extension for
                Internationalized Email", RFC 6531, February 2012.

   [RFC6532]    Yang, A., Steele, S., and N. Freed, "Internationalized
                Email Headers", RFC 6532, February 2012.

Author's Address

   Robert Sparks
   Tekelec
   17210 Campbell Road
   Suite 250
   Dallas, Texas  75254-4203
   USA

   EMail: RjS@nostrum.com

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