rfc2287.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                                       C. Krupczak
Request for Comments: 2287                    Empire Technologies, Inc.
Category: Standards Track                                    J. Saperia
                                                       BGS Systems Inc.
                                                          February 1998


      Definitions of System-Level Managed Objects for Applications

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Table of Contents

   1 Abstract ..............................................    2
   2 The SNMPv2 Network Management Framework ...............    2
   2.1 Object Definitions ..................................    2
   3 Overview ..............................................    3
   4 Architecture for Application Management ...............    3
   5 The Structure of the MIB ..............................    4
   5.1 System Application Installed Group ..................    5
   5.2 System Application Run Group ........................    5
   5.2.1 sysApplRunTable and sysApplPastRunTable ...........    5
   5.2.2 sysApplElmtRunTable and  sysApplElmtPastRunTable
        ....................................................    6
   5.3 System Application Map Group ........................    7
   6 Definitions ...........................................    7
   7 Implementation Issues .................................   40
   7.1 Implementation with Polling Agents ..................   40
   7.2 sysApplElmtPastRunTable Entry Collisions ............   40
   8 Security Considerations ...............................   41
   9 Acknowledgements ......................................   42
   10 Author's Address .....................................   42
   11 References ...........................................   42
   12 Full Copyright Statement .............................   44







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1.  Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes a basic set of managed objects for fault,
   configuration and performance management of applications from a
   systems perspective.  More specifically, the managed objects are
   restricted to information that can be determined from the system
   itself and which does not require special instrumentation within the
   applications to make the information available.

   This memo does not specify a standard for the Internet community.

2.  The SNMPv2 Network Management Framework

   The SNMPv2 Network Management Framework consists of the following
   major components:

   o    RFC 1902 Structure of Management Information for Version
        2 of the Simple Network Management Protocol (SNMPv2) [2]

   o    RFC 1903 Textual Conventions for Version 2 of the Simple
        Network Management Protocol (SNMPv2) [3]

   o    RFC 1904 Conformance Statements for Version 2 of the
        Simple Network Management Protocol (SNMPv2) [4]

   o    RFC 1905 Protocol Operations for Version 2 of the Simple
        Network Management Protocol (SNMPv2) [5]

   o    RFC 1906 Transport Mappings for Version 2 of the Simple
        Network Management Protocol (SNMPv2) [6]

   o    RFC 1907 Management Information Base for Version 2 of the
        Simple Network Management Protocol (SNMPv2) [7]

   o    RFC 1908 Coexistence between Version 1 and Version 2 of
        the Internet-standard Network Management Framework [8]

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

2.1.  Object Definitions

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB. Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1) [1],
   defined in the Structure of Management Information (SMI)  (See RFC



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   1902 [2]). In particular, each object type is named by an OBJECT
   IDENTIFIER, an administratively assigned name. The object type
   together with an object instance serves to uniquely identify a
   specific instantiation of the object. For human convenience, we often
   use a textual string, termed the object descriptor, to refer to the
   object type.

3.  Overview

   The primary purpose of computing technologies is the execution of
   application software. These applications, typically specialized
   collections of executables, files, and interprocess communications,
   exist to solve business, scientific or other "problems". The
   configuration, fault detection, performance monitoring and control of
   application software across its life on a host computer is of great
   economic importance. For the purposes of our work, we define
   applications as one or more units of executable code and other
   resources, installed on a single host system that a manager may think
   of as a single object for management purposes.

   The information described by the objects in the System Application
   MIB support configuration, fault, and performance management; they
   represent some of the basic attributes of application software from a
   systems (non-application specific) perspective.  The information
   allows for the description of applications as collections of
   executables and files installed and executing on a host computer.

   This memo is concerned primarily with, and defines a model for,
   application information resident on a host computer which can be
   determined from the system itself, and not from the individual
   applications.  This system-level view of applications is designed to
   provide information about software applications installed and running
   on the host system without requiring modifications and code additions
   to the applications themselves.  This approach was taken to insure
   ease and speed of implementation, while allowing room for future
   growth.

4.  Architecture for Application Management

   In the area of application management it is fully acknowledged and
   even expected that additional MIB modules will be defined over time
   to provide an even greater level of detail regarding applications.
   This MIB module presents the most general case:  a set of management
   objects for providing generic information about applications and
   whose object values can be determined from the computer system itself
   without requiring instrumentation within the application.





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   A finer-grained level of detail is planned for the future "appl MIB"
   which will be a common set of management objects relating to generic
   applications, but which require some type of instrumentation in the
   application in order to be determined.  Since the applmib MIB module
   will provide a finer level of detail, any connection to the sysAppl
   MIB should be made by having references from the more detailed appl
   MIB back to the more generic sysAppl MIB.  Likewise, as application-
   specific MIB modules such as the WWW MIB, etc., are developed over
   time, these more specific MIBs should reference back to the more
   generic MIBs.

   While this MIB module does not attempt to provide every detailed
   piece of information for managing applications, it does provide a
   basic systems-level view of the applications and their components on
   a single host system.

5.  The Structure of the MIB

   The System Application MIB structure models application packages as a
   whole, and also models the individual elements (files and
   executables) which collectively form an application.  The MIB is
   structured to model information regarding installed application
   packages and the elements which make up each application package. The
   MIB also models activity information on applications (and in turn,
   their components) that are running or have previously run on the host
   system.  In modeling applications and their elements, this MIB module
   provides the necessary link for associating executing processes with
   the applications of which they are a part.

   The objects are arranged into the following groups:

       -  System Application Installed Group
              - sysApplInstallPkgTable
              - sysApplInstallElmtTable

       -  System Application Run Group
              - sysApplRunTable
              - sysApplPastRunTable
              - sysApplElmtRunTable
              - sysApplElmtPastRunTable
              - (scalars for restricting table sizes)

       -  System Application Map Group
              - sysApplMapTable







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   As can be seen by the arrangement above, for each category, the MIB
   first treats an application package as a whole, and then breaks down
   the package to provide information about each of the elements
   (executable and non-executable files) of the package.

5.1.  System Application Installed Group

   The System Application Installed group consists of two tables.
   Through these two tables, administrators will be able to determine
   which applications have been installed on a system and what their
   constituent components are.  The first table, the
   sysApplInstallPkgTable, lists the application packages installed on a
   particular host. The second, the sysApplInstallElmtTable, provides
   information regarding the executables and non-executable files, or
   elements, which collectively compose an application.

   NOTE: This MIB is intended to work with applications that have been
   installed on a particular host, where "installed" means that the
   existence of the application and the association between an
   application and its component files can be discovered without
   requiring additional instrumentation of the application itself.  This
   may require that certain conventions be used, such as using a central
   software installation mechanism or registry, when installing
   application packages.  For example, many UNIX systems utilize a
   "pkgadd" utility to track installed application packages, while many
   PC systems utilize a global registry.

5.2.  System Application Run Group

   This group models activity information for applications that have
   been invoked and are either currently running, or have previously
   run, on the host system.  Likewise, the individual elements of an
   invoked application are also modeled to show currently running
   processes, and processes that have run in the past.  This information
   is modeled using two pairs of tables: a pair of tables for currently
   running applications and past run applications, and a pair of tables
   for the currently running elements and the past run elements.  Seven
   scalars are also defined to control the size of the past run tables.

5.2.1.  sysApplRunTable and sysApplPastRunTable

   The sysApplRunTable and the sysApplPastRunTable make up the first
   pair of tables.  The sysApplRunTable contains the application
   instances which are currently running on the host.  Each time an
   application is invoked, a new entry is created in the sysApplRunTable
   to provide information about that particular invocation of the
   application.  An entry will remain in this table until the




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   application instance terminates, at which time the entry will be
   deleted from the sysApplRunTable and placed in the
   sysApplPastRunTable.

   The sysApplPastRunTable maintains a history of instances of
   applications which have previously executed on the host.  Entries to
   this table are made when an invoked application from the
   sysApplRunTable terminates; the table entry which represents the
   application instance is removed from the SysApplRunTable and a
   corresponding entry is added to the sysApplPastRunTable.

   Because the sysApplPastRunTable will continuously grow as
   applications are executed and terminate, two scalars are defined to
   control the aging-out of table entries. The value of
   sysApplPastRunMaxRows specifies the maximum number of entries the
   table may contain, while the sysApplPastRunTblTimeLimit specifies the
   maximum age of the table entries.  Oldest entries are removed first.

   It is important to note that the sysApplRunTable and
   sysApplPastRunTable contain entries for each INVOCATION of an
   application. A single application package might be invoked multiple
   times; each invocation is properly recorded by a separate entry in
   the sysApplRunTable.

   In order to implement this group, the agent must be able to recognize
   that an application has been invoked, and be able to determine when
   that invocation terminates.  This poses a complex problem since a
   single application invocation may involve numerous processes, some of
   which may be required to remain running throughout the duration of
   the application, others which might come and go.  The
   sysApplInstallElmtRole columnar object in the sysApplInstallElmtTable
   is meant to assist in this task by indicating which element is the
   application's primary executable, which elements must be running in
   order for the application to be running, which elements are dependent
   on required elements, etc.  See the description of