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Use Monitor III to easily identify problems related to data sets.
A key requirement of many RMF users is to help them to identify problems on a data set level. When many address spaces use or wait for a device, or when a job shows high device delays, you might want to know which data sets are the reason for these delays or the cause for potential problems in the system. OS/390 V2R4 RMF now provides three new Monitor III reports which help you to answer these questions. The reports let you examine:
- all data sets and the jobs using the data sets for a selected volume,
- all data sets used by a selected job,
- a set of selected data sets and the jobs using these data sets.
The reports give you the ability to view data set usage from these angles and they are named respectively:
Your Feedback Is Important to Us
The Data Set Delays - Volume (DSNV) Report is the logical step for further investigation of device usage after you identified devices with an interesting amount of jobs using or being delayed for the device. You can directly navigate to the report from the Device Resource Utilization (DEVR) report through cursor-sensitive control from the volume serial number of the device.
Figure 1 shows the DSNV report. The first part of the report provides a general overview on important activity and delay data for the volume. The second part displays a list of all data sets on this volume and the jobs using and being delayed for the data sets.
Figure 1. DSNV Report
RMF 2.4.0 Data Set Delays - Volume Line 1 of 10
Command ===> Scroll ===> HALF
Samples: 100 System: MVS1 Date: 08/20/97 Time: 10.03.20 Range: 100 Sec
-------------------------- Volume EDSS99 Device Data --------------------------
Number: 0B4A Active: 84% Pending: 22% Average Users
Device: 3380E Connect: 10% Delay DB: 22% Delayed
Shared: Yes Disconnect: 52% Delay CU: 0% 0.4
Delay DP: 0%
-------------- Data Set Name --------------- Jobname ASID DUSG% DDLY%
RMF.R430.NLS.OLDENG.ERBFMTS3.SEQ BSDSPD58 0022 3 20
BGGEETEO 0201 2 16
BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK BOECL2 003C 20 15 >
BGGEETEO 0201 15 10
BDA.CTT.MSPCT.SP41XCTT.GUIDE BOECL2 003C 13 10
BGGEETEO 0201 10 8
-- N/A -- *MASTER* 0001 0 10
RMF.R430.NLS.OLDENG.ERBCOPS3.SEQ BOECL2 003C 3 8
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You can use this report as base for further investigation. In our example, we want to take a look at all data sets used by job BOECL2. By simply selecting the job (highlighted in Figure 1) with the cursor and pressing Enter we can continue with the "Data Set Delays - Job Report" (DSNJ).
The DSNJ report presents information about the data set utilization for a specific job:
- The EXCP Rate and the percentage of time when data transfer for this job took place.
- A list of all data sets being utilized by the job.
You can continue your examination from the DSNJ report by selecting a specific data set name to display the Data Set Delays (DSND) report via cursor-sensitive control.
Figure 2. DSNJ Report
RMF 2.4.0 Data Set Delays - Job Line 1 of 5
Command ===> Scroll ===> HALF
Samples: 100 System: MVS1 Date: 08/20/97 Time: 10.03.20 Range: 100 Sec
Jobname: BOECL2 EXCP Rate: 123.5 Connect: 41%
ASID -------------- Data Set Name --------------- Volume Num DUSG% DDLY%
003C BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK EDSS99 0312 20 15
BDA.CTT.MSPCT.SP41XCTT.GUIDE EDSS99 0312 13 10
RMF.R430.NLS.OLDENG.ERBCOPS3.SEQ EDSS09 0312 3 8
-- N/A -- ------ ---- 1 7
BHEW.IGX00022.LST90514 DATA38 0122 1 6
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In our example, we will use a different way. By examining the DSNV and DSNJ report, we found that job BOECL2 used data sets starting with BDA.CTT* most often. We will now look at all data sets starting with this prefix. In order to do this, we simply enter DSND BDA.CTT* on the command line. As a result the "Data Set Delays Report" is displayed.
Figure 3. DSND Report
RMF 2.4.0 Data Set Delays Line 1 of 6
Command ===> Scroll ===> HALF
Samples: 100 System: MVS1 Date: 08/20/97 Time: 10.03.20 Range: 100 Sec
Input Data Set Name: BDA.CTT*
-------------- Data Set Name --------------- Volume Jobname ASID DUSG% DDLY%
BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK EDSS99 BOECL2 003C 20 15
BGGEETEO 0201 15 10
BDA.CTT.MSPCT.SP41XCTT.GUIDE EDSS99 BOECL2 003C 13 10
BGGEETEO 0201 10 8
BDA.CTTX.TEST DATA94 BSHR 0022 3 16
BDA.CTT0.INFORM.SEQ DATA67 BSHR 0074 3 8
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The DSND report completes the set of new reports for data set level analysis. The report lists the volume for the data set or group of data sets displayed in the report and the jobs using or waiting for them.
We complete our journey now by looking at all data sets with prefix BDA.CTT.
The DSND Report Options panel is displayed when you enter the command DSND in the command line and no report option has been specified previously or the command RO from the DSND report.
The panel lists all data set names which have been found active during the reporting interval. You can select a data set name by placing S in front of the displayed data set name.
Figure 4. DSND Report Options Panel
RMF DSND Report Options Line 1 of 12
Command ===> Scroll ===> HALF
Select (S) or fill-in a data set name or a group of data set names
for the DSND report. To exit press END.
Selected Data Set Name: BDA.CTT*
Sel Data Set Name
_ BDA.CTT.MSPCT.SP41XCTT.CTTGUIDE.BOOK
_ BDA.CTT.MSPCT.SP41XCTT.GUIDE
_ BDA.CTT0.INFORM.SEQ
_ BDA.CTTX.TEST
_ BHEW.IGX00022.LST90514
_ BSHR.FIX.LINKLIB
_ RMF.R430.NLS.OLDENG.ERBCOPS3.SEQ
_ RMF.R430.NLS.OLDENG.ERBFMTS3.SEQ
_ RMF.R430X10.LPALIB
_ RMF.R430X10.SRMFCLS
_ RMF.R430X10.SRMFJPN
_ RMF.R530.FPFS
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The selected name is re-displayed in the header field Selected Data Set Name. This field is an input field, which can be used to enter the data set name directly.
In our example we see BDA.CTT* in the input field Selected Data Set Name, because we invoked the DSND report for all datasets starting with the prefix BDA.CTT.
The three new reports provide using and delay statistics for all jobs accessing the data sets during the report interval. The respective columns on the reports are named DUSG% and DDLY%. The DEVR report provides also using and delay information for jobs accessing the device. At a first glance you will see that the report column names on the DEVR report are named USG% and DLY%. The different names have been chosen intentionally. The RMF data gatherer collects device using and delay information in a multistate fashion, this means there may be several wait records for the same job to the same device.
On the DEVR report multiple using and delay counts for the same job are combined to one USG counter and one DLY counter.
On the Data Set Delays reports this is different. Several wait records referring to the same device are not treated as being the same because they may refer to different data sets. As a result, the sum of the USG% and DLY% values on the DEVR report can be different from the sum of the DUSG% and DDLY% values on the Data Set Delays reports.
In our journey exploring the new reports in the previous chapter, we used cursor-sensitive control and report command DSND to invoke the new reports. Figure 5 now gives a complete overview how the new reports are imbedded in the RMF Monitor III panel hierarchy.
The reports can be seen as an extension of the DEVR report. From the DEVR report, you can invoke the DSNV report via cursor-sensitive control. Cursor-sensitive control is also always available to switch between the three new reports if you want to look at the data from a different view point.
Figure 5. Invocation of New Reports
The dotted lines show the RMF Monitor III report hierarchy. The DSNV and DSND report can be invoked from the Resource Report Menu with the options 3A and 3B. The DSNJ report has been added to the Job Report Menu as option 1A. In addition you can invoke all reports with the immediate commands DSNV, DSNJ and DSND.
The new Data Set Level reports are a significant enhancement to analyze performance problems with RMF Monitor III. In order to exploit the new functionality you need OS/390 V2R4 with at least DFSMS 1.1.0. The RMF Monitor III is then able to collect the data set information if the SMS subsystem is active.
Looking at the DSNV report (see Figure 1) and the DSNJ report (see Figure 2) we see that sometimes the data set name can't be identified. If this is the case, -- N/A -- is printed instead of the data set name. This situation occurs for some data sets for which no measurements are available:
- IMS OSAM for erlier IMS versions then IMS 5.1
- IMS Fats Path for earlier IMS versions then IMS 5.1
- System data sets, like paging and spool data sets
- Data sets opened before the SMS subsystem has been activated
RMF Monitor III collects data set statistics only for DASD devices. For tape data sets which can also be examined via the DEVR report no data set information is available.
If you like the idea of the 'RMF Newsletters', or if you don't like it, or if you have suggestions for topics you want to hear about, please contact:
Robert Vaupel - in the Boeblingen Lab
Phone (49-7031-164239), Fax (49-7031-164240)
IBMMAIL.COM or IBMMAIL(DEIBMRMF)
© IBM Corp. 1997
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