4. EXCEPTIONS › 4.3 Detailed Exception Descriptions › 06017: MFS I/O Rate Exceeds Standard

06017: MFS I/O Rate Exceeds Standard

    FILE:            IMS System Activity
    SAS FILE NAME:   DETAIL.IMSISY01
    SOURCE LOCATION: sharedprefix.MICS.SOURCE(DYIMSEXC)

    SEVERITY:        Critical      (SEVERITY='C')
    MANAGEMENT AREA: Performance   (MGMTAREA='PERFORMANCE')

    PURPOSE:  Identifies the time period during which the
message MFS pool was over-committed.

    RATIONALE:  An abnormally high MFS I/O rate may indicate
misuse of MFS.  Proliferation of formats with no attempt to
use common displays may lead to high I/O here.  The use of
the in-core directory $$IMSDIR is strongly recommended.  As
each entry is only fourteen bytes, most installations include
all formats in this directory.  If this is the case, there
should be no directory I/O.  However, if there are more
formats than will fit in $$IMSDIR (2339 entries in a 32K pool
out of the MFS pool), then the most often referenced formats
should be included to minimize I/O.  A large directory I/O
rate indicates a non-optimum choice of formats to be included
in the directory.  A consistently high I/O value may dictate
an increase in MFS pool size.

    DEFINITION:  This exception is detected when the MFS I/O
rate exceeds the installation-defined limit.

    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:

*
**  06017
**  MFS I/O RATE EXCEEDS STANDARD
*;
IF ISYPSMFB > I/O-rate
 THEN DO;
  EXCCODE='06017'; SEVERITY='C'; MGMTAREA='PERFORMANCE';
  EXCDESC1=
  'MFS I/O RATE EXCEEDS STANDARD';
  EXCDESC2='MFS I/O RATE ='
           || PUT(ISYPSMFB,7.2);
  LINK HIT;
END;

    THRESHOLD MODIFICATION:  Modify the value used for the
MFS I/O-rate.