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-
- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- Network Working Group Joanne Sattley
- Request for Comments: 744 JZS@CCA
- NIC: 42857 8 January 1978
-
-
- MARS - A Message Archiving & Retrieval Service
-
-
- I. Introduction
- ------------
-
- This document describes a Message Archiving and Retrieval Service
- (MARS) which has been developed at Computer Corporation of America; it
- utilizes the Datacomputer, a network database utility developed by CCA
- for ARPA. [Research and development of a prototype MARS system was
- supported by the Defense Advanced Research Projects Agency of the
- Department of Defense, under the ARPA Very Large Databases program,
- and was monitored by the Office of Naval Research under Contract No.
- N00014-76-C-0991.]
-
- The Service is available, primarily, to groups for storage of
- teleconferencing transcripts. Is is also available, upon request, to
- individual ARPANET correspondents.
-
- There are both 'public' and 'private' messages in the database.
- Public messages may be retrieved by anyone. The public collection
- includes the messages of the Header-People [@ MIT-MC] group, and the
- MsgGroup [@ USC-ISI] proceedings.
-
- Private messages may be retrieved only by the users who have archived
- them, or anyone whose name appears on the list of message recipients.
-
- Messages archived using MARS are heavily indexed and can be retrieved
- in a variety of ways, including Boolean combinations of message
- recipients, message composition date, any text words in the message
- subject, and text words in the message body. The MARS facilities are
- integrated very naturally into the existing collection of
- message-handling tools:
-
- . A message is designated for archiving by sending it to
- MARS-Filer @ CCA using one of the usual message-mailing tools such
- as SNDMSG.
-
- . A message is designated for retrieval by sending a request as
- ordinary mail to MARS-Retriever @ CCA.
-
- The Filer program checks for mail every hour; the Retriever program
- checks every quarter-hour. The periodicity can be altered to meet
- demand but the intent is for MARS to operate as a background job and
- only during extremely low-activity periods.
-
- The next section (II) describes the indexing operation in greater
- detail, and how to archive and retrieve messages. The last section
- (III) is an extractable user card.
-
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- [Page 1]
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- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- MARS - A Message Archiving & Retrieval Service
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- II. Using MARS
- ----------
-
- A. Message Indexing
- ----------------
-
- For each message, a vector of parsed tokens is created. The parsed
- tokens are collected by the message-field in which they occurred -- to
- be used as "indexes", i.e., values of inverted fields, by the
- Datacomputer.
-
- The Filer "indexes", essentially without analysis, except for the
- following:
-
- -- Each distinguishable section of the message is indexed
- separately; each header line is a separate inversion domain, as
- is the body of the message.
-
- -- The header lines which contain ARPANET addresses are analyzed in
- order to index separately on mailbox and host.
-
- -- The date-field is parsed and converted to the standard Tenex
- internal date/time format, which is better adapted for
- less-than/greater-than comparisons, as in retrievals which
- specify a date range.
-
- -- One-character words in both the subject-field and the
- message-text field arbitrarily discarded.
-
- -- Two-character words in the message-text field are arbitrarily
- discarded.
-
- -- Hyphenated phrases, i.e., words bound together by hyphens, are
- retained intact.
-
- -- All message formats which conform to RFC 733 standards are
- accommodated. The minimum requirements are: a date-field, a
- from-field, and a blank line between the message-header and
- message-body.
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- [Page 2]
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- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- MARS - A Message Archiving & Retrieval Service
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-
-
- B. To Archive Messages
- -------------------
-
- There are three modes of filing currently supported by MARS, to wit:
-
- -- single-message mode, wherein the MARS-Filer mailbox appears in
- the message as an addressee;
-
- -- forwarded-message mode, wherein the MARS-Filer mailbox appears as
- the only primary recipient;
-
- and
-
- -- batch mode, wherein the mailing envelope is addressed to
- MARS-Filer and the subject-field contains the keyword "batch".
-
- Until the ARPANET standard for the format of messages is implemented
- universally, the variability amongst formats is still greater than the
- Filer can handle as it stands. Nonetheless, a user can successfully
- file any message in a "foreign" format by forwarding it to the Filer
- under the aegis of a mail-handling program which does produce good
- formats. Admittedly, the correct header-field indexing, as described
- above, will not be done on the enclosed message; but at least, the
- words in its unreadable header fields will appear as "text" words in
- the indexing.
-
- In the case of forwarded-message-mode filing, all interesting indexing
- information is extracted from the message-header of the forwarding
- envelope prior to discarding it. The name of the archiver, the date
- and time the message was forwarded, and the subject-line information
- are recorded. The remainder is handled as though it were a
- non-forwarded message which had been CC'd to the Filer.
-
- A forwarded message may be 'annotated' by adding text (e.g., notes,
- comments, keywords) in the forwarding envelope. Annotations are filed
- and retrieved as part of the archived message.
-
- In the case of batch-mode filing, only the archiver's name and the
- date and time s/he sent the package are extracted from the mailing
- envelope. The message-body portion is then treated as a series of
- individual messages.
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- [Page 3]
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- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- MARS - A Message Archiving & Retrieval Service
-
-
-
- C. To Retrieve Messages
- --------------------
-
- Retrievals are initiated by sending a Retrieval Request (which is a
- specially formatted message) to "MARS-Retriever@CCA". Retrieved
- messages are mailed back, one at a time, and will appear as new mail
- in the requester's mailbox.
-
- Retrieval Request messages can be composed using any SNDMSG-type of
- program, as follows:
-
- . The recipient of the RR message must be MARS-Retriever @ CCA
-
- . Other message header fields are ignored for now
-
- . The message body portion of the RR is used to compose Datalanguage
- for performing the retrieval. Its format resembles a message
- header, or selected portions thereof.
-
- The following list defines which field names are recognized, and some
- notes on their interpretation. The scanning of each field is
- terminated by a carriage-return.
-
- DATE: The format of the date field is day-month-year. Use of
- hyphens is optional. This field will cause only those
- messages composed on the specified date to be retrieved.
-
- AFTER: Use of this field will retrieve messages composed after
- the specified date.
-
- SINCE: This field is interpreted like the AFTER: field.
-
- BEFORE: Use of this field will retrieve messages composed before
- the specified date.
-
- UNTIL: This field is interpreted like the BEFORE: field.
-
- FROM: This field is expected to contain a valid mailbox name.
- The host specification is optional. If more than one name
- is specified, ORing of the names is implicit.
- Retrieval based upon host specification alone has not been
- implemented.
-
- TO: This field is expected to contain one or more valid
- mailbox names. The host specification is optional. Spaces
- and commas between the names imply AND.
-
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- [Page 4]
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- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- MARS - A Message Archiving & Retrieval Service
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-
-
- SUBJECT: Use of this field will retrieve all messages whose
- indexed subject-field contents match the specified
- word(s). Spaces and commas imply AND. The use of OR
- must be explicit.
-
- TEXT: Use of this field will retrieve all messages whose
- indexed message-body contents match the specified
- word(s). Spaces and commas imply AND. The use of OR
- must be explicit.
-
- An interactive TENEX-based program for composing RRs is available;
- the filename is "RR.SAV". A copy of this program is stored on the
- Datacomputer, available via DFTP under node COMMON>MARS.
-
- There is also a copy of the program in CCA's directory at SRI-KA;
- another in the CCA-ACCAT directory at ISIA.
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- [Page 5]
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- NWG/RFC 744 JS5 8-Jan-78 21:59 42857
- MARS - A Message Archiving & Retrieval Service
-
-
-
- III. MARS User Card
- --------------
-
- :: Archiving
- ---------
-
- Individual Messages
-
- . Include MARS-Filer@CCA on message distribution list
-
- . Forward message to MARS-Filer@CCA [Annotation is optional.]
-
- Batches of Messages
-
- . Incorporate the mail file as the message-body of a single
- message sent to MARS-Filer@CCA with the clue "BATCH" in its
- subject-field.
-
- :: Retrieving
- ----------
-
- Using RR Program
-
- . RR is a TENEX-based interactive program designed to prepare
- Retrieval Request messages and to mail them to MARS-Retriever@CCA.
-
- Using SNDMSG-Type Program
-
- . Send a message to MARS-Retriever@CCA, specifying the retrieval
- criteria in the body of the message.
-
- Sample Retrieval Criteria
-
- SUBJECT:RFC 733 or RFC733 ; OR must be explicit
-
- TEXT:MARS Project,goals ; spaces & commas imply AND
-
- DATE: 14 November 1977
- SINCE: 1 Nov 77 ; same as AFTER: 1 Nov 77
- AFTER: 1 Dec 1977
- UNTIL: 15 January 1978 ; same as BEFORE: 15 January 1978
- BEFORE: Aug 7 76
-
- FROM: JZS@CCA ; host specification is optional
- FROM: Hacker,JZS ; comma implies OR (in FROM: field only)
-
- TO: CCA@SRI-KA ; host specification is optional
- TO: SDD-0:,SDD-1: ; spaces and commas imply AND
-
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- [Page 6]