Collecting data about APPC-related DC problems

APPC problems that originate from IMS dependent regions and that make calls explicitly rely heavily on the dependent region dumps.

To diagnose an APPC-related IMS problem:

Procedure

Turn on the IMS LUMI trace for the external trace data set by issuing the following IMS /TRACE commands:
```
/TRACE SET ON TABLE LUMI OPTION LOG 
```
The LOG option can be set up to cause the output to be sent to the external trace data set with this /TRACE command:
```
/TRACE SET ON LUNAME XXXXXXX INPUT
```
```
TRACE SET ON LUNAME XXXXXXX OUTPUT
```
where XXXXXXX is the partner LU
Turn on the VTAM® buffer trace and VTAM internal trace to complement the IMS LUMI trace by issuing the following commands:
```
F NET,TRACE,TYPE=BUF,ID=luname
```
```
F NET,TRACE,TYPE=VTAM,MODE=EXT,
  OPT=(API,PIU,MSG)F
```
To capture these trace entries, GTF must be active with the USR option specified
Turn on the program trace to trace TPPCB DL/I calls, so that the APPC component trace can send its trace buffers to a SYS1.DUMP data set when it stops. Turn on the program trace by issuing the following command:
```
/TRACE SET ON PROGRAM pppppppp
```
where pppppppp is the program name of the application.
Turn on the z/OS® APPC component trace by issuing the following command:
```
TRACE CT,ON,200M,COMP=SYSAPPC
```
Note: If the command above fails, omit the ON keyword.
Start the recreate attempt after issuing an IMS /SWITCH OLDS command to have related data placed in a new OLDS. Save the IMS log tapes that are created during the error period. IMS log records are not as useful for explicit APPC applications as they are for implicit APPC applications because little information is logged about explicit APPC applications.
Reply to the z/OS outstanding reply with the following response:
```
nn,OPTIONS=(GLOBAL),END
```
When the problem has been recreated, stop the component trace with this command:
```
TRACE CT,OFF,COMP SYSAPPC
```
You can use the following IPCS commands to format the trace:
- For one-line entries:
```
CTRACE COMP SYSAPPC  SHORT 
```
- Summary of each entry:
```
CTRACE COMP SYSAPPC  FULL
```
Obtain a z/OS SVC dump of the IMS regions with this series of commands:
```
DUMP COMM=(dump title)
R id JOBNAME=(j1,j2,j3,j4,j5,j6),
SDATA=(CSA,PSA,RGN,SQA,SUM,TRT),END
```
In the previous example,

j1

is the IMS CTL or DBCTL region job name

j2

is the IMS DL/I region job name

j3

is the suspicious IMS dependent region job name, if any

j4

is the suspicious CCTL (CICS®) region name, if any

j5

is the IRLM region job name (if IRLM DB locking is used)

j6

is the DBRC region job name
Obtain a dump of the APPC, APPC Scheduler, and VTAM address spaces with this series of commands:
```
DUMP COMM=(dump title)
R id JOBNAME=(j1,j2,j3),SDATA=(CSA,PSA,RGN,SQA,SUM,TRT),END
```
In the previous example,

j1

is the APPC job name

j2

is the APPC scheduler job name

j3

is the VTAM job name