Monitoring MFS activity

You can obtain a summary of all activity that occurs for management of message format buffer pool use from the Message Format Buffer Pool report.

The report is illustrated in the following example. The data shows the counts at the start and end of the trace interval and their difference.

When message formatting occurs, the appropriate message blocks must reside in the message format buffer pool, a DIF/MID pair for input or a DOF/MOD pair for output. If the blocks are not already in the buffer, I/O to the active IMS.FORMATA/B library must occur. Block retrieval can involve a prior directory lookup, or be direct, using an index kept in the pool.

Many of the counts reveal details of internal event management. When there is no directory entry for a block this implies extra directory lookup I/O.

***I M S  M O N I T O R***  BUFFER POOL STATISTICS  TRACE START 1993 130   5:55:15  TRACE STOP  1993 130   5:59:49  PAGE 0007
 
                   M E S S A G E   F O R M A T   B U F F E R   P O O L
 
                                                                            5:55:15            5:59:49
                                                                         START TRACE        END   TRACE        DIFFERENCE
 
    NUMBER OF P/F REQUESTS                                                       0                  0                  0
    NUMBER OF I/F REQUESTS                                                      18                 20                  2
    NUMBER OF I/F I/O'S                                                          2                  2                  0
    NUMBER OF TIMES POOL COMPRESS WOULD BE SUCCESSFUL                            0                  0                  0
    NUMBER OF DIRECTORY I/O OPERATIONS                                           2                  2                  0
    NUMBER OF TIMES BLOCK WASHED FOR FRE                                         0                  0                  0
    NUMBER OF TIMES P/F REQUEST IGNORED                                          0                  0                  0
    NUMBER OF F/B REQUESTS                                                      18                 20                  2
    NUMBER OF TIMES F/B REQUEST IGNORED                                          0                  0                  0
    NUMBER OF TIMES I/F ON F/B QUEUE                                            16                 18                  2
    NUMBER OF TIMES I/F ON I/F QUEUE                                             0                  0                  0
    NUMBER OF TIMES F/B ON I/F QUEUE                                            18                 20                  2
    NUMBER OF TIMES P/F ON I/F QUEUE                                             0                  0                  0
    NUMBER OF TIMES P/F ON F/B QUEUE                                             0                  0                  0
    NUMBER OF TIMES THERE WAS NO DIR ENTR FOR A BLOCK                            0                  0                  0
    NUMBER OF TIMES I/O ERRORS POINT OR READ MACRO                               0                  0                  0
    NUMBER OF IMMEDIATE I/O REQUESTS WAITED DUE TO MAXIMUM I/O                   0                  0                  0
    NUMBER OF REQUESTS SATISFIED BY INDEX/DYNAMIC DIRECTORY                      0                  0                  0
 
    QUOTIENT :  IMMEDIATE FETCH I/O'S + DIRECTORY I/O'S OPERATIONS =    0.00
                ___________________________________________________________________________________
                                            TOTAL NUMBER OF TRANSACTIONS