rfc2039.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. Kalbfleisch
Request for Comments: 2039                    OnRamp Technologies, Inc.
Category: Informational                                   November 1996


    Applicablity of Standards Track MIBs to Management of World Wide
                              Web Servers

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

1. Abstract

   This document was produced at the request of the Network Management
   Area Director following the HTTP-MIB BOF at the 35th IETF meeting to
   report on the applicability of the existing standards track MIBs to
   management of WWW servers.

   Requirements for management of a World Wide Web (WWW) server are
   presented.  The applicable existing standards track MIBs are then
   examined.  Finally, an analysis of the additional groups of MIB
   attributes that are needed to meet the requirements is presented.

Table of Contents

  1.     Abstract.................................................1
  2.     Overview.................................................2
  3.     Requirements.............................................3
  3.1    Operational Model Requirements...........................3
  3.1.1. Host specific and Application Monitoring.................3
  3.1.2. Dependencies among applications..........................3
  3.1.3. Error generation and reporting...........................3
  3.1.4. Capacity planning........................................4
  3.1.5. Log Digester.............................................4
  3.2.   Service Model Requirements...............................4
  3.2.1. Retrieval services.......................................4
  3.2.2. Document information store -- managing documents.........4
  3.2.3. Server configuration.....................................4
  3.2.4. Server Control...........................................4
  3.2.5. Quality of Service.......................................4
  4.     Relationship to existing IETF efforts....................5
  4.1.   MIB-II [2]...............................................5
  4.2.   Host Resources MIB [3]...................................5
  4.3.   Network Services Monitoring MIB [4]......................6
  4.4.   Application MIB [5]......................................7



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RFC 2039                     WWW Track MIBs                November 1996


  5.     Summary of Existing Standards Track MIBs.................8
  6.     Definition of additional attributes......................9
  7.     Usage Scenarios.........................................11
  8.     Conclusion..............................................11
  9.     References..............................................13
  10.    Acknowledgments.........................................13
  11.    Further Information.....................................14
  12.    Security Considerations.................................14
  13.    Authors' Address........................................14

2. Overview

   The World Wide Web (WWW) is a network of information, accessible via
   a simple easy to use interface.  The information is often presented
   in HyperText or multi-media.  The information is provided by servers
   which are located all around the world.  The usability of the web
   depends largely on the performance of these servers. WWW servers are
   typically monitored through log files.  This becomes a difficult task
   when a single organization is responsible for a number of servers.
   Since many organizations currently use the Internet Standard SNMP to
   manage their network devices, it is desirable to treat these WWW
   servers as additional devices within this framework. This will allow
   a single Network Management Station (NMS) to automate the management
   of a number of WWW servers as well as the entire enterprise. Defining
   a standard for this purpose allows a single management application to
   manage a number of servers from a variety of vendors.  Additionally,
   a formal definition of what has to be managed and how to manage it
   tends to lead to integrated and improved performance and fault
   management.

   Content providers are interested in the access statistics and
   configuration of their sites. The content provider may be the same or
   a different organization than the one that maintains the server as a
   whole. It may be possible to realize the new paradigm of "Customer
   Network Management" to provide this information to the content
   provider. This means that there exists a distinct organization
   different than the network operations center that is also interested
   in the management information from a device. Customer network
   management is desirable to allow each content provider on a server to
   access information about his own documents independent of the rest.

   Various organizations may be interested in SNMP manageable WWW
   clients and proxies as well. At this time, our focus is on WWW
   servers. A natural extension to this work could be a framework for
   managing WWW Clients and general information retrieval systems like
   WWW proxies, NNTP, GOPHER, FTP and WAIS.  The focus of this document
   remains the management of WWW servers.




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RFC 2039                     WWW Track MIBs                November 1996


3. Requirements

   WWW servers can be viewed from several perspectives when assigning
   management responsibilities.  For the sake of discussion, these
   perspectives are named the Operational Model and the Service Model.
   The Operational Model views WWW servers as computers with hardware,
   disk, OS and web server software.  This model represents the actual
   resources that make up the machine so that it can be monitored from
   the perspective of resource utilization.  The Service Model views the
   WWW server as a black box that simply handles the responses to
   requests from clients located on the web.

   The two models compliment each other while providing distinct
   information about the server.  Members of the organization
   responsible for the WWW server, may be interested in one and/or both
   of the management models.  For this reason, the management
   information should be scalable, for one or both models to be
   implemented independent of the other.

   With this in mind, the requirements for WWW server management can are
   summarized below by expanding upon those generated at the HTTP-MIB
   BOF.

3.1  Operational Model Requirements

3.1.1. Host specific and Application Monitoring

   This includes monitoring the utilization of CPU, disk and network
   capacity.

3.1.2. Dependencies among applications.

   Some systems implement a number of services within a single piece of
   code. Others use multiple pieces of code to implement the same set of
   services. Because of this, dependencies develop among processes.
   These dependencies become critical when a particular process needs to
   be stopped, restarted or reconfigured. These dependencies need to be
   defined within the management information so that management
   applications can operate the systems correctly.

3.1.3. Error generation and reporting

   The WWW server generally reports errors via logging facilities.  The
   format of the log file is not well defined.  It is required that a
   standard facility for error reporting be utilized.






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RFC 2039                     WWW Track MIBs                November 1996


3.1.4. Capacity planning

   It is required to obtain statistics which can be used for capacity
   planning purposes. This includes planning for increased network
   bandwidth, computing power, disk space, number of concurrent server
   threads, etc.

3.1.5. Log Digester

   WWW servers generally report status information by data generated in
   Common Log Format [1].  This information needs to be preserved as
   attributes in a MIB to facilitate remote monitoring providing a
   standard way to represent and retrieve the management information.

3.2. Service Model Requirements

3.2.1. Retrieval services

   Retrieval services are an abstract decoupling the information space
   from the underlying transport mechanism.  The goal at this time is to
   focus on the requirements for management of WWW servers. There may be
   considerable overlap with other types of servers like (FTP, NNTP,
   GOPHER and WAIS).  The term "retrieval services" is used here to
   retain this abstraction.  It is required to get statistics about the
   usage and performance of the retrieval services.

3.2.2. Document information store -- managing documents.

   Information from a WWW server can be static (a file) or dynamic (the
   output of some processing).  Management of these two types of
   information sources range from maintaining access statistics and
   access permissions to verifying the operational status of all
   applications that provide the dynamic information.

3.2.3. Server configuration.

   It is desirable to be able to centralize configuration management of
   the servers within an enterprise.

3.2.4. Server Control.

   WWW servers generally need to be controlled in regards to starting
   and stopping them as well as rotating log files.

3.2.5. Quality of Service

   Provide an indication of the quality of service the WWW server is
   providing.



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RFC 2039                     WWW Track MIBs                November 1996


4. Relationship to existing IETF efforts

   In general, a WWW server is made up of or depends upon the following
   components:

      -a general purpose workstation running some operating system
      -http server software to answers requests from the network
      -various support routines like CGI programs or external
       applications (like DBMS) used to access information
      -a document store on one or more storage devices

   The health and performance of each of the above components is of
   interest when managing a WWW server.

   There are a number of standards track MIB modules that are of
   interest to the above list of items.  This list includes MIB-II [2],
   Host Resources MIB [3], Network Service Monitoring MIB [4] and
   Application MIB [5].

   This creates an impressive list of attributes to be implemented.  A
   definition of various levels of management of a WWW server is desired
   so that the implementor may scale his implementation in chunks which
   may include various components of each section.  For instance, this
   may allow customer network management without requiring the other
   groups being implemented.

4.1. MIB-II [2]

   MIB-II defines the managed objects which should be contained within
   TCP/IP based devices.

   The WWW server should support the applicable portions of MIB-II.
   This set probably includes, as a minimum, the following groups: