Monitoring activity in dependent regions
The IMS Monitor gathers timing information for every dependent region identified in the /TRACE command (a CCTL thread) active during the trace interval. It records the total of the elapsed times for each event, the maximum individual time encountered, and the average time.
There are three major reports that display timings. The reports and a list of their content are:
- Region Summary Report
- Scheduling and termination
- Schedule end to first call
- Elapsed execution with separate summaries shown for:
- DL/I calls
- External subsystem service and command calls
- External subsystem database access calls
- Checkpoint processing
- Region occupancy
- Region Wait
- Waits during scheduling and termination
- Waits during DL/I calls
- Waits during external subsystem calls
- Waits during checkpoint
- Programs by Region
- Elapsed execution
- Schedule end to first call
In this report, program name
is the PSB name for the UOR.
These three reports are illustrated in the following examples.
Activities in dependent regions are placed in five timing categories:
- Elapsed time for scheduling and termination
The scheduling process includes many preparatory events such as block loading from an active IMS.ACBLIBA/B data set, and obtaining ownership of the PSB. The time required to terminate is the time it takes DBCTL to complete this process after receiving a request to terminate the UOR.
- Elapsed time from end of schedule to first call
This is the time from when DBCTL completes scheduling until the time DBCTL reviews the first DL/I call. Events that occur during this time are all outside of DBCTL, either in the database resource adapter (DRA) or the CCTL.
- Program elapsed time, including all calls
This time encompasses the major UOR processing, measured from the first DL/I call to the call that terminates a UOR.
- Elapsed time performing DL/I calls
This time includes all DL/I calls. The time in DBCTL is recorded and summed.
The following example shows a region summary report.
IMS MONITOR ****REGION SUMMARY**** TRACE START 1993 130 5:55:15 TRACE STOP 1993 130 5:59:49 PAGE 0011
(A) (B)
........ELAPSED TIME......... NOT IWAIT TIME(ELAPSED-IWAIT) DISTRIBUTION
OCCURRENCES TOTAL MEAN MAXIMUM TOTAL MEAN MAXIMUM NUMBER
___________ _____ ____ _______ _____ ____ _______ ______
SCHEDULING AND TERMINATION
__________ ___ ___________
**REGION 5 5 4146 829 948 4146 829 948 287A,B
**REGION 6 7 6028 861 1067 6028 861 1067 214A,B
**REGION 8 8 6847 855 1098 6847 855 1098 129A,B
**REGION 10 7 9664 1380 3668 9664 1380 3668 272A,B
**REGION 47 6 5482 913 1021 5482 913 1021 145A,B
**REGION 49 3 2612 870 917 2612 870 917 443A,B
**TOTALS 123 126042 1024 126042 1024
SCHEDULE TO FIRST CALL
________ __ _____ ____
**REGION 1 1 15479797 15479797 15479797 555
**REGION 2 1 22376350 22376350 22376350 564
**REGION 3 1 15169488 15169488 15169488 578
**REGION 4 1 48146258 48146258 48146258 584
**REGION 48 1 795351 795351 795351 592
**REGION 49 4 2960425 740106 2951746 442
**REGION 50 1 15713464 15713464 15713464 575
**TOTALS 168 514286738 3061230
ELAPSED EXECUTION
_______ _________
**REGION 1 1 290146255 290146255 290146255 1
**REGION 2 1 252290108 252290108 252290108 2
**REGION 3 1 259496970 259496970 259496970 3
**REGION 4 1 322812716 322812716 322812716 4
**REGION 48 1 273871107 273871107 273871107 48
**REGION 49 4 271703421 67925855 155176058 49
**REGION 50 1 290379922 290379922 290379922 50
**TOTALS 173 14238540145 82303700
DL/I CALLS IWT/CALL(C)
____ _____ ___________
**REGION 1 60 264626241 4410437 88981490 263813671 4396894 88970053 0.76 247A,B,C
**REGION 2 223 230505269 1033655 61048758 227368742 1019590 61011153 0.73 237A,B,C
**REGION 3 29 257704383 8886358 69000514 257704383 8886358 69000514 0.00 98A,B,C
**REGION 4 792 313735347 396130 52439653 310609035 392183 52439653 0.22 180A,B,C
**REGION 49 592 262886317 444064 30202068 234394017 395935 30159782 2.46 177A,B,C
**REGION 50 36 242591451 6738651 48651260 242591451 6738651 48651260 0.00 289A,B,C
**TOTALS 18632 12386905286 664818 12024562411 645371 0.97
IDLE FOR INTENT
____ ___ ______
NONE
CHECKPOINT
__________ NONE
REGION OCCUPANCY
______ _________
**REGION 1 100.0%
**REGION 2 100.0%
**REGION 3 100.0%
**REGION 4 100.0%
**REGION 48 100.0%
**REGION 49 100.0%
**REGION 50 100.0%The following example shows a region wait report.
IMS MONITOR ****REGION IWAIT**** TRACE START 1993 130 5:55:15 TRACE STOP 1993 130 5:59:49 PAGE 0023
.........IWAIT TIME.......... DISTRIBUTION
**REGION 5 OCCURRENCES TOTAL MEAN MAXIMUM FUNCTION MODULE NUMBER
______ ___________ _____ ____ _______ ________ ______ ______
SCHEDULING + TERMINATION
__________ ___________
SUB-TOTAL
_________
TOTAL
_____
DL/I CALLS
____ _____
11 181816 16528 24375 DD=IMMSTR2A DBH 117
1 1667 1667 1667 PSB=BMPFPE06 BLR-64BIT 11
1 1635 1635 1635 INT=BMPFPE06 BLR-64BIT 12
8 112831 14103 17846 DD=IMMSTR1A DBH 118
5 85460 17092 33717 DD=IMMSTR3A DBH 119
5 58420 11684 14643 DD=IMINDEXA VBH 120
12 173866 14488 22152 DD=PRODCNTA VBH 121
3 100576 33525 68373 DD=IMMSTR2B DBH 428
1 17921 17921 17921 DD=IMMSTR3B DBH 429
1 17195 17195 17195 DD=IMMSTR1B DBH 430
1 13577 13577 13577 DD=IMINDEXB VBH 431
3 49928 16642 20396 DD=PRODCNTB VBH 432
4 10973 2743 2787 DD=ITEMACTB DBH 453
2 37680 18840 27664 DD=IAINDEXB VBH 454
49 1500067 30613 138284 DD=INVENTRA DBH 472
23 345595 15025 27613 DD=VENDORDA VBH 473
1 342952 342952 342952 PI=VENDORDA...1 498
1 14612 14612 14612 PI=VNSINDXA...1 499
6 69203 11533 19492 DD=VNSINDXA VBH 500
TOTAL
_____ 136 3132672 23034The following example shows a programs-by-region report.
IMS MONITOR ****PROGRAMS BY REGION**** TRACE START 1993 130 5:55:15 TRACE STOP 1993 130 5:59:49 PAGE 0069
(A) (B)
ELAPSED EXECUTION TIME SCHEDULING END TO FIRST CALL DISTRIBUTION
OCCURRENCES TOTAL MEAN MAXIMUM TOTAL MEAN MAXIMUM NUMBER
___________ _____ ____ _______ _____ ____ _______ ______
**REGION 1
________ _ 1
PROGSC6D 1 290146255 290146255 290146255 15479797 15479797 15479797 885A,B
REGION TOTALS 1 290146255 290146255 15479797 15479797
**REGION 2
________ _ 2
PROGIT8C 1 252290108 252290108 252290108 22376350 22376350 22376350 889A,B
REGION TOTALS 1 252290108 252290108 22376350 22376350
**REGION 3
________ _ 3
PROGTS1C 1 259496970 259496970 259496970 15169488 15169488 15169488 893A,B
REGION TOTALS 1 259496970 259496970 15169488 15169488
**REGION 4
________ _ 4
PROGPS3D 1 322812716 322812716 322812716 48146258 48146258 48146258 897A,B
REGION TOTALS 1 322812716 322812716 48146258 48146258
**REGION 5
________ _ 5
PROGPS3A 2 62893103 31446551 40693590 5435 2717 2862 901A,B
PROGTS1B 1 61794787 61794787 61794787 2790 2790 2790 1271A,B
PROGPS3B 1 18294458 18294458 18294458 3104 3104 3104 1350A,B
PROGIT2B 1 36095342 36095342 36095342 2731 2731 2731 1363A,B
PROGSC2A 1 93902771 93902771 93902771 1667791 1667791 1667791 1401A,B
REGION TOTALS 6 272980461 45496743 1681851 280308
**REGION 6
________ _ 6
PROGIT1B 2 39000315 19500157 23703429 5286 2643 2801 905A,B
PROGTS1B 1 34293636 34293636 34293636 3136 3136 3136 1207A,B
PROGPS3A 1 51887767 51887767 51887767 2534 2534 2534 1278A,B
PROGPS3B 2 67375031 33687515 40291430 17210570 8605285 17213287 1328A,B
PROGIT8A 1 69132416 69132416 69132416 3291 3291 3291 1359A,B
PROGSC4A 1 30165017 30165017 30165017 2571 2571 2571 1433A,B
REGION TOTALS 8 291854182 36481772 17193752 2149219
**REGION 7
________ _ 7
PROGSC2B 1 269618583 269618583 269618583 5047875 5047875 5047875 909A,B
REGION TOTALS 1 269618583 269618583 5047875 5047875
**REGION 8
________ _ 8
PROGIT8A 1 5181039 5181039 5181039 2928 2928 2928 913A,B
PROGPS3A 1 27304257 27304257 27304257 3350 3350 3350 1132A,B
PROGSC4B 1 37286872 37286872 37286872 3009 3009 3009 1255A,B
PROGIT2A 1 36902995 36902995 36902995 2850 2850 2850 1298A,B
PROGIT1B 1 30407479 30407479 30407479 2565 2565 2565 1336A,B
PROGIT1A 3 109875360 36625120 45190114 4279008 1426336 4272096 1357A,B
PROGIT8B 1 23405220 23405220 23405220 2679 2679 2679 1395A,B
REGION TOTALS 9 270363222 30040358 4296389 477376Detecting database processing intent conflicts
The IMS Monitor records the intervals when a region is in an idle state waiting to update a database owned exclusively by another already scheduled application program.
You can see the total, maximum, and average idle times in IDLE FOR INTENT following the DL/I calls. The elapsed time during the unsuccessful scheduling of a program in that region is included in the summary line times for that region.
The region can fail to be scheduled even when ownership of that database is released. The number of times processing is held up by intent failure is separately tallied under the title INTENT FAILURE SUMMARY. The report is illustrated in Detecting database processing intent conflicts. This report shows which PSBs are in conflict because of exclusive intent for a segment type and the database name in question.
Examining the effects of checkpoints
The checkpoint line of the Region Summary report at the end of the region 0 summary, shows the following:
- The number of times that a system checkpoint is taken during the monitor interval
- The elapsed times
- The not-wait times
Checkpoint processing can be initiated by the control program at a specified frequency determined by the number of records placed on the system log. Other checkpoints can be caused by operator commands.
The wait time experienced during checkpoints is reported at the end of the first region summary on the Region Wait report. You can detect delays for each combination of DD name and module code. Typical entries here are for the message queue data sets and the restart data set. If a wait for storage is the cause, the entry under the FUNCTION column is STG.= followed by the identification of the pool.
Measuring region occupancy
Region occupancy shows the ratio of elapsed time a PST spent processing UORs to the total time of the monitor interval.