Processing a dump using the IBM MQ for z/OS dump
display panels
We can use commands available through IPCS panels to process dumps. Use this topic to
understand the IPCS options.
IBM MQ for z/OS provides a set of panels to help you
process dumps. The following section describes how to use these panels:
From the IPCS PRIMARY OPTION MENU, select ANALYSIS - Analyze dump
contents (option 2).
The IPCS MVS ANALYSIS OF DUMP CONTENTS panel is displayed.
Select COMPONENT - MVS component data (option 6).
The IPCS MVS DUMP
COMPONENT DATA ANALYSIS panel is displayed. The appearance of the panel depends on the products
installed at your installation, but will be similar to the panel shown in IPCS MVS Dump Component Data Analysis
panel:
Figure 1. IPCS MVS Dump Component Data Analysis panel
---------------- IPCS MVS DUMP COMPONENT DATA ANALYSIS -------------
OPTION ===> SCROLL ===
To display information, specify "S option name" or enter S to the
left of the option required. Enter ? to the left of an option to
display help regarding the component support.
Name Abstract
ALCWAIT Allocation wait summary
AOMDATA AOM analysis
ASMCHECK Auxiliary storage paging activity
ASMDATA ASM control block analysis
AVMDATA AVM control block analysis
COMCHECK Operator communications data
CSQMAIN WebSphere MQ dump formatter panel interface
CSQWDMP WebSphere MQ dump formatter
CTRACE Component trace summary
DAEDATA DAE header data
DIVDATA Data-in-virtual storage
Select CSQMAIN IBM MQ dump formatter
panel interface by typing s next to the line and pressing Enter.
If
this option is not available, it is because the member CSQ7IPCS is not present; we should see Configure z/OS
for more information about installing the IBM MQ for z/OS dump formatting member.
Note: If we have already used the dump to do a preliminary analysis, and we want to reexamine it,
select CSQWDMP IBM MQ dump
formatter to display the formatted contents again, using the default options.
The IBM MQ for z/OS - DUMP ANALYSIS menu is displayed.
Use this menu to specify the action that we want to perform on a system dump.
---------------IBM WebSphere MQ for z/OS - DUMP ANALYSIS----------------
COMMAND ===>
1 Display all dump titles 00 through 99
2 Manage the dump inventory
3 Select a dump
4 Display address spaces active at time of dump
5 Display the symptom string
6 Display the symptom string and other related data
7 Display LOGREC data from the buffer in the dump
8 Format and display the dump
9 Issue IPCS command or CLIST
(c) Copyright IBM Corporation 1993, 2020. All rights reserved.
F1=Help F3=Exit F12=Cancel
Before we can select a particular dump for analysis, the dump you require must be present in
the dump inventory. To ensure that this is so, perform the following steps:
If we do not know the name of the data set containing
the dump, specify option 1 - Display all dump titles xx through xx.
This
displays the dump titles of all the dumps contained in the SYS1.DUMP data sets (where xx is a number
in the range 00 through 99). We can limit the selection of data sets for display by using the xx
fields to specify a range of data set numbers.
To see details of all available dump data sets, set these values to 00 and 99.
Use the information displayed to identify the dump we want to analyze.
If the dump has not been copied into another data set (that is, it is in one of the SYS1.DUMP
data sets), specify option 2 - Manage the dump inventory
The dump inventory contains the dump data sets that we have used. Because the SYS1.DUMP data
sets are reused, the name of the dump that you identified in step 5.a
might be in the list displayed. However, this entry refers to the previous dump that was stored in
this data set, so delete it by typing DD next to it and pressing Enter. Then press F3 to return to
the DUMP ANALYSIS MENU.
Specify option 3 - Select a dump, to
select the dump that we want to work with. Type the name of the data set containing the dump in the
Source field, check that NOPRINT and TERMINAL are specified in the Message Routing field (this is to
ensure that the output is directed to the terminal), and press Enter. Press F3 to return to the DUMP
ANALYSIS MENU.
Having selected a dump to work with, we can now use the other options on the menu to analyze
the data in different parts of the dump:
To display a list
of all address spaces active at the time the dump was taken, select option 4.
To display the symptom string and other
serviceability information, including the variable recording area of the system diagnostic work area
(SDWA), select option 6.
To format and display the data
contained in the in-storage LOGREC buffer, select option 7.
It could be that the abend that
caused the dump was not the original cause of the error, but was caused by an earlier problem. To
determine which LOGREC record relates to the cause of the problem, go to the end of the data set,
type FIND ERRORID: PREV, and press Enter. The header of the latest LOGREC record is
displayed, for example:
Note the program identifier (if it is not 5655R3600,
the problem was not caused by IBM MQ for z/OS and you could
be looking at the wrong dump). Also note the value of the TIME field. Repeat the command to find the
previous LOGREC record, and note the value of the TIME field again. If the two values are close to
each other (say, within about one or two tenths of a second), they could both relate to the same
problem.
To format and display
the dump, select option 8. The FORMAT AND DISPLAY THE DUMP panel is displayed:
---------IBM MQ for z/OS - FORMAT AND DISPLAY DUMP--------
COMMAND ===>
1 Display the control blocks and trace
2 Display just the control blocks
3 Display just the trace
Options:
Use the summary dump? . . . . . . . . . . . . . . __ 1 Yes
2 No
Subsystem name (required if summary dump not used) ____
Address space identifier or ALL. . . . . . . . . . ALL_
F1=Help F3=Exit F12=Cancel
Use this panel to format your selected system dump. We can choose to display control blocks,
data produced by the internal trace, or both, which is the default. Note: We cannot do this for
dumps from the channel initiator, or for dumps of coupling facility structures.
To display the whole of the dump, that is:
The dump title
The variable recording area (VRA) diagnostic information report
The save area trace report
The control block summary
The trace table
select option 1.
To display the information listed for option 1, without the trace table, select option 2.
To display the information listed for option 1, without the control blocks, select option 3.
We can also use the following options:
Use the Summary Dump?
Use this field to specify whether we want IBM MQ to
use the information contained in the summary portion when formatting the selected dump. The default
setting is YES.
Note: If a summary dump has been taken, it might include data from more than one address space.
Subsystem name
Use this field to identify the subsystem with the dump data we want to display. This is only
required if there is no summary data (for example, if the operator requested the dump), or if you
have specified NO in the Use the summary dump? field.
If we do not know the
subsystem name, type IPCS SELECT ALL at the command prompt, and press Enter to
display a list of all the jobs running at the time of the error. If one of the jobs has the word
ERROR against it in the SELECTION CRITERIA column, make a note of the name of that job. The job name
is of the form xxxx MSTR, where xxxx is the
subsystem name.
IPCS OUTPUT STREAM -------------------------
COMMAND ===>
ASID JOBNAME ASCBADDR SELECTION CRITERIA
---- -------- -------- ------------------
0001 *MASTER* 00FD4D80 ALL
0002 PCAUTH 00F8AB80 ALL
0003 RASP 00F8C100 ALL
0004 TRACE 00F8BE00 ALL
0005 GRS 00F8BC00 ALL
0006 DUMPSRV 00F8DE00 ALL
0008 CONSOLE 00FA7E00 ALL
0009 ALLOCAS 00F8D780 ALL
000A SMF 00FA4A00 ALL
000B VLF 00FA4800 ALL
000C LLA 00FA4600 ALL
000D JESM 00F71E00 ALL
001F MQM1MSTR 00FA0680 ERROR ALL
If no job has the word ERROR against it in the SELECTION CRITERIA column, select option 0 -
DEFAULTS on the main IPCS Options Menu panel to display the IPCS Default Values panel. Note the
address space identifier (ASID) and press F3 to return to the previous panel. Use the ASID to
determine the job name; the form is xxxx MSTR, where
xxxx is the subsystem name.
The following command shows which ASIDs are in the dump data set:
LDMP DSN('SYS1.DUMPxx') SELECT(DUMPED) NOSUMMARY
This shows the storage ranges dumped for each address space.
Press F3 to return to the FORMAT AND DISPLAY THE DUMP panel, and type this name in the
Subsystem name field.
Address space identifier
Use this field if the data in a dump comes from more than one address space. If you only want to
look at data from a particular address space, specify the identifier (ASID) for that address space.
The default value for this field is ALL, which displays information about all the address spaces
relevant to the subsystem in the dump. Change this field by typing the 4-character ASID over the
value displayed.
Note: Because the dump contains storage areas common to all address spaces, the information
displayed might not be relevant to your problem if we specify the address space identifier
incorrectly. In this case, return to this panel, and enter the correct address space identifier.