4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 01002: CPU Underutilized

01002: CPU Underutilized

FILE: CPU Activity File
SAS FILE NAME: DAYS.HARCPU01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

SEVERITY: Warning              (SEVERITY='W')
MANAGEMENT AREA: Performance   (MGMTAREA='PERFORMANCE')

PURPOSE:  Detects an underutilized CPU.

RATIONALE:  An underutilized CPU may result from lack of
workload or may serve as an indication of poor performance.
When the operating system is overcommitted (page faulting,
I/O delays, and so on), processor utilization may decrease
because the supervisor and workload are waiting
unnecessarily.  Detection of low processor utilization may
identify periods of poor performance, permitting further
investigation of the critical resources.

DEFINITION:  This exception is detected when the CPU wait
percentage is above the installation-defined maximum.

EXCEPTION STATEMENTS:  The SAS statements identifying the
exception situation and describing the condition are stored
in the source member named in SOURCE LOCATION and are
described below:

** 01002 CPU UNDERUTILIZED;
*;
IF (CPUMXPWT GT percent) AND
   (HOUR GE hh1 AND HOUR LE hh2) AND
   (DAYNAME EQ 'MON' OR DAYNAME EQ 'TUE' OR DAYNAME EQ 'WED'
    OR DAYNAME EQ 'THU' OR DAYNAME EQ 'FRI')
 THEN DO;
  EXCCODE='01002'; SEVERITY='W'; MGMTAREA='PERFORMANCE';
  EXCDESC1='CPU UNDERUTILIZED';
  EXCDESC2='CPU WAIT=' !! PUT(CPUMXPWT,5.1) !! '%';
  LINK HIT;
END;


THRESHOLD MODIFICATION:  The user should modify the percent
value and prime time according to the following conventions:

percent - The maximum CPU wait percent is specified.  A 10
percent threshold would appear as:

CPUMXPWT GT 10

prime time - The hour range and days of the week to be
included in the exception are specified.  The hour of the day
must be within the hh1 through hh2 range.  Prime time
specified as 8:00 am through 6:59 pm (18:59) would appear as:

(HOUR GE 8 AND HOUR LE 18)

The days of the week are represented by the first three
characters of their names.  They must be enclosed in quotes,
separated with ORs.  Prime time specified as MONDAY through
FRIDAY would appear as:

(DAYNAME EQ 'MON' OR DAYNAME EQ 'TUE' OR DAYNAME EQ 'WED'
OR DAYNAME EQ 'THU' OR DAYNAME EQ 'FRI')

The time period to be included may already be defined by
means of the ZONE definition, which would provide a simpler
method of selecting hours and days for processing.  If ZONE 1
corresponds to the desired time period, it would appear as:

ZONE='1'