4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 02751: IOP Request Rate Exceeds Max

02751: IOP Request Rate Exceeds Max

FILE: I/O Processor Queueing File
SAS FILE NAME: DAYS.SCPIOP01
SOURCE LOCATION: prefix.MICS.USER.SOURCE(DYRMFEXC)

SEVERITY: Impacting            (SEVERITY='I')
MANAGEMENT AREA: Performance   (MGMTAREA='PERFORMANCE')

PURPOSE:  Identify excessive activity by the I/O processor
(IOP).

RATIONALE:  The rate at which the IOP processes I/O requests
is one of the basic measurements of the activity of a CPC.
An unusually high rate of I/O requests could indicate that
there is a problem in the I/O subsystem or that the workload
of the CPC is not well balanced.

DEFINITION:  This exception is detected when the average IOP
request rate exceeds the installation-defined maximum.  The
threshold will vary greatly with the I/O configuration and
workload being executed by the CPC.

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:

/* **************************************
**  02751 IOP REQUEST RATE EXCEEDS MAX **
************************************** */
IF IOPAVRQS GT request-rate
 THEN DO;
  EXCCODE='02751'; SEVERITY='I'; MGMTAREA='PERFORMANCE';
  EXCDESC1='IOP REQUEST RATE EXCEEDS MAX';
  EXCDESC2='REQUEST RATE=' !! PUT(IOPAVRQS,6.1) !!
            '/SEC, IOPID=' !! IOPID ;
  LINK HIT;
END;

THRESHOLD MODIFICATION:  The user should modify the
request-rate value according to the following convention:

request-rate - The maximum I/O request rate of the IOP is
specified.  A threshold of 500 operations per second would
appear as:

IOPAVRQS GT 500