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.

   system, interfaces, udp, icmp, tcp and snmp.

4.2. Host Resources MIB [3]

   This MIB defines a uniform set of objects useful for the management
   of host computers independently of the operating system, network
   services, or any software application.

   The MIB is structured as six groups; each specified as either
   "mandatory" or "optional".  If ANY "optional" group of the MIB is
   implemented, then ALL "mandatory" groups of the MIB must also be
   implemented.  This may cause implementation problems for some
   developers since many of these attributes require intimate knowledge
   of the OS.




Kalbfleisch                  Informational                      [Page 5]

RFC 2039                     WWW Track MIBs                November 1996


   The groups defined by the MIB are:

      -System Group                           Mandatory
      -Storage Group                          Mandatory
      -Device Group                           Mandatory

                -device types
                -device table
                -processor table
                -network table
                -printer table
                -disk storage table
                -partition table
                -file-system table
                -file-system types
      -Running Software Group                 Optional
      -Running Software Performance Group     Optional
      -Installed Software Group               Optional

   The system group provides general status information about the host.
   The storage and device groups define the information about the
   configuration and status of the resources which compose the host.  It
   defines the resources which make up a generic host system and how
   they relate to each other.  Much of this information is useful for
   managing various aspects of a WWW server, like the file system and
   CPU utilization.  This information is useful for meeting the
   operational requirements. Much of this information is however more
   detailed than many WWW server managers require for service level
   requirements.

   The remaining groups define software components which are installed
   and/or running on the host.  Performance information is defined which
   extends that defined for each running process.  Unfortunately, the
   mapping between running software and installed software is difficult
   since it is related by a foreign key (Product ID) which does not
   appear to be required to exist in either table [6]. There is no
   provision to represent a group of processes which together perform
   some task (IE an application made up of multiple processes). The
   Applications MIB WG plans to address these deficiencies.

4.3. Network Services Monitoring MIB [4]

   This MIB is one of three documents produced by the MADMAN (Message
   And Directory MANagement) Working group.  It defines a set of general
   purpose attributes which would be appropriate for a range of
   applications that provide network services.  This definition is from
   the perspective of the service without considering the implementation
   in terms of host computers or processes.  Attributes provide



Kalbfleisch                  Informational                      [Page 6]

RFC 2039                     WWW Track MIBs                November 1996


   statistics and status on the in-bound and out-bound associations that
   are currently active, and which have been active.

   This MIB is intended to be the minimum set of attributes common
   across a number of Network Service Applications.  Additional
   attributes are to be defined as necessary to manage specific network
   service applications.  WWW servers clearly fall into the category of
   network service applications.  All attributes in this MIB are
   relevant to WWW servers.

   The MIB consists of two tables:

           -applTable                  Mandatory
           -assocTable                 Optional

   The applTable describes applications that provide network services
   and keeps statistics of the current number of active associations and
   the total number of associations since application initialization.
   The assocTable contains more detailed information about active
   associations.

   The other two MIBs defined by MADMAN, MTA MIB [7] and DSA MIB [8],
   are not relevant to the management of WWW services.  They do,
   however, demonstrate how to extend the Network Services Monitoring
   MIB for a specific set of applications.

4.4. Application MIB [5]

   The Application MIB WG is defining two separate MIBs: the sysApplMib
   and the applMib.  The first defines attributes that can be monitored
   without instrumenting the applications.  The second will define
   additional attributes requiring application instrumentation.

   The sysApplMIB allows for the description of applications as a
   collection of executables, and files installed and executing on a
   host computer. The objects support configuration, fault and
   performance management of some of the basic attributes of application
   software.













Kalbfleisch                  Informational                      [Page 7]

RFC 2039                     WWW Track MIBs                November 1996


   The groups defined in the sysApplMIB are:

           -System Application Installed Group     Mandatory
                   -sysApplInstalledTable
                   -sysApplCfgElmtTable

           -System Application Run Group           Mandatory
                   -sysApplRunTable
                   -SysApplPastRunTable
                   -sysApplElmtRunTable
                   -sysApplElmtPastRunTable

   The sysApplInstalledTable captures what applications are installed on
   a particular host and the sysApplCfgElmtTable provides information
   regarding the executables and non executable files which collectively
   compose the application. The sysApplRunTable contains the application
   instances which are currently running and the sysApplPastRunTable
   contains a history about applications which have previously executed
   on the host. The sysApplElmtRunTable contains the process instances
   which are currently running and sysApplElmtPastRunTable contains a
   history about processes which have previously executed on the host.

   It should be noted that two implementations of the same set of
   network services may each define a different set of processes and
   files within this MIB.  Ultimately enough management information is
   needed so that these different implementations can at least be
   managed similarly.

   WWW servers fall into the general category of application software.
   Therefore the attributes of this MIB are applicable if the process
   level detail is requested to meet the Operational Model requirements.

   The Application MIB WG is to resolve the problems described above
   with the relationship between the running and installed software of
   the Host Resources MIB.

5. Summary of Existing Standards Track MIBs

   The existing MIBs are largely orthogonal as demonstrated by the
   diagram below.  Host Resources relates network information to the
   interfaces defined in MIB-II.  The system application MIB relates its
   running element table to the equivalent entry in the Host Resources
   running software table.

   It should be noted that the running software of the Host Resources
   includes ALL software running on the host, while the running element
   table of the system application MIB only includes "interesting"
   processes of monitored applications.



Kalbfleisch                  Informational                      [Page 8]

RFC 2039                     WWW Track MIBs                November 1996


   In the diagram below, "Other Services", "Application Specific MIBs"
   and "Application MIB" represent work to be done or in progress.

                          +---------------+
                          |  Application  |
                          | Specific MIBs |
                          +---------------+
                                 |
  +--------+ +---+ +---+  +---------------+
  |Other   | |MTA| |DSA|  |  Application  |
  |services| |MIB| |MIB|  |      MIB      |
  +--------+ +---+ +---+  +---------------+
      |        |     |           |
  +--------------------+  +---------------+  +--------------+  +------+
  |  Network Services  |  |    System     |  |Host Resources|  |MIB-II|
  |   Monitoring MIB   |  |Application MIB|--|     MIB      |--|      |
  +--------------------+  +---------------+  +--------------+  +------+

   The stack of MIBs above "Network Services Monitoring MIB" represent
   monitoring from the Service Model.  The other stacks represent
   monitoring from the Operational Model.  Neither of these stacks goes
   to the level of specific detail for any application. The author is of
   the opinion that HTTP or Web Server specific MIBs would exist at the
   top of each stack to represent the service and implementation view of
   the server respectively.  There should be a relationship between
   these two perspectives defined so that the correlations between the
   two perspectives is possible.  This relationship would be useful for
   general application and service monitoring in addition to just web
   servers.  However, it is not of specific interest to either the
   MADMAN WG or the Application MIB WG. It is therefore suggested that
   such a relationship is defined in a general case outside of either of
   those groups that would be applicable for WWW servers as well as for
   other application to service mappings.

6. Definition of additional attributes

   The existing MIB attributes meet the Operational Model Requirement
   for tracking information specific to a host.  Specifically, MIB-II,
   Host Resources and the Applications MIB address these items. The
   Network Services MIB addresses a portion of the service model
   requirement for the decoupling of the information space from the
   transport mechanism.

   Several sets of additional attributes are needed to meet the
   remaining requirements. These additional attributes may be generally
   applicable to other network information retrieval services (like FTP,
   NNTP, GOPHER and WAIS) as well as client and proxy management.
   Management of these services is not the scope of this document.



Kalbfleisch                  Informational                      [Page 9]

RFC 2039                     WWW Track MIBs                November 1996


   These additional attributes can be classified as:

   1) Definition of relationship between the Network Services Monitoring
      and Application MIBs.  This allows the functional organization of
      the server to be known.  It allows the management application to
      understand the effect of restarting specific processes on the
      services provided.  This addresses the Operational Model
      requirement to model dependencies between applications.

   2) Additions to generic Network Services Monitoring MIB. A draft [9]
      has already been circulated due to the work of a mailing list and
      a sample implementation.  These attributes list a summary at the
      service level of the configuration and the health of the server.
      From this, performance metrics can be observed.  In addition, the
      health of the server in terms of data timeouts is known.  These
      attributes address the requirement for Operational Model tracking