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Performance Monitor Interface

IP.com Disclosure Number: IPCOM000116012D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 140K

Publishing Venue

IBM

Related People

Overby, L: AUTHOR [+2]

Abstract

Disclosed is a method, known as the Performance Monitor Interface, which provides a formal interface by which a performance monitor program can request and receive data relating to the performance and resource usage of a monitored program. With the Performance Monitor Interface, the performance monitor program is independent of the internal structure of the monitored product which is typically proprietary, subject to change, and/or undocumented. Additionally, the collection of the data is done in a way that minimizes performance impact of the data collections on the system by the monitor program.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 43% of the total text.

Performance Monitor Interface

      Disclosed is a method, known as the Performance Monitor
Interface, which provides a formal interface by which a performance
monitor program can request and receive data relating to the
performance and resource usage of a monitored program.  With the
Performance Monitor Interface, the performance monitor program is
independent of the internal structure of the monitored product which
is typically proprietary, subject to change, and/or undocumented.
Additionally, the collection of the data is done in a way that
minimizes performance impact of the data collections on the system by
the monitor program.

      Performance monitors report data relating to the performance
and resource usage of some other program (subsequently referred to as
the monitored program).  The current methodology used by performance
monitors to derive this information is to "take" this information
from the monitored program.  The monitor takes the data by extracting
directly from the monitored program's control blocks which in many
cases are proprietary and subject to change without notice.

This method has several shortcomings:
  o  The monitor program can fail if the monitored product's control
      block structures change (as the result of product redesign)
      without an accompanying change to performance monitor program
      data collection logic.
  o  The monitor program can fail since its access to the data is
      typically not serialized with the monitored product's control
      blocks allocation/deallocation.

      The Performance Monitor Interface allows the monitored program
to report or "give" the data to the monitor program upon request.
With this approach, the performance monitor is no longer dependent on
the internals of the monitored product.  The reported data is a
product external and not subject to change.  Serialization with
control block allocation/deallocation is no longer required.

      A secondary problem with the control block interrogation method
is related to the system overhead sometimes required when data
desired by the monitor program is not available in the control block.
With the control block interrogation approach, the monitored product
is not involved or is not cooperating with the performance monitor
program.  The monitored program may therefore, have little
performance-related statistics maintenance built into its design.
Therefore, the data is not readily available to the monitor and must
be derived.  One technique used by monitor programs is known as
sampling.  With sampling, data in the control block of the monitored
product is sampled frequently (every second or less) in order to
derive a statistic.  Many times the monitor program runs as one of
the highest priority programs in a system in order to ensure that it
runs frequently enough to sample.  Another technique used by monitor
products is counting.  Control block chains are follow...