When the system logger address space hangs

The following commands can be useful as diagnostic aids when the system logger address space hangs. For a full description of these commands, see z/OS MVS System Commands.

To display couple data sets in use for system logger:
```
D XCF,COUPLE,TYPE=LOGR
```
To display the status of a structure:
```
D XCF, STR,STRNAME=structurename
```
To display the status of the system logger address space (IXGLOGR) on this system:
```
D LOGGER,STATUS
```
To display the connection status of logstreams and jobs on this system:
```
D LOGGER,CONNECTION,...
```
To display logstream activity from a sysplex view (for example, from the LOGR couple data set):
```
D LOGGER,LOGSTREAM,...
```
To display structure activity from a sysplex view (for example, from the LOGR couple data set):
```
D LOGGER,STRUCTURE,...
```
To see if there is any contention:
```
D GRS,C
```
To see if there is a logger resource serialization contention:
```
D GRS,RES=(SYSZLOGR,*)
```
To see what units of work are blocking GRS-managed resources:
```
D GRS,ANALYZE,BLOCK,SYSTEM=*,JOBNAME=IXGLOGR
```
To see what units of work are waiting for ownership of GRS-managed resources:
```
D GRS,ANALYZE,WAIT,SYSTEM=*,JOBNAME=IXGLOGR
```
To see the dependencies between units of work and resources that are in contention:
```
D GRS,ANALYZE,DEPEND,SYSTEM=*,JOBNAME=IXGLOGR,DETAIL
```

Run the IXCMIAPU utility and specify the following:

DATA TYPE(LOGR) REPORT(YES)
   LIST STRUCTURE NAME(structurename|*) DETAIL(YES)
   LIST STRUCTURE NAME(structurename|*) DETAIL(YES)

See Administrative data utility for a full description of the TYPE(LOGR) LIST options.

If there is a problem with a single application, attempt to stop and restart the application before stopping logger. If stopping the applications that have connections to log streams related to the difficulty, it may be necessary to force a log stream to be disconnected from a system using the SETLOGR FORCE,DISCONNECT command. See z/OS MVS System Commands.

If there is a problem with a structure, a rebuild may help resolve the problem. Issue the following command:

SETXCF START,REBUILD,STRNAME=structurename

If there is no logger (LOGR) couple data set, issue the following command to define the logger couple data set(s):

SETXCF COUPLE,TYPE=LOGR,PCOUPLE=(primarydataset,volser),
ACOUPLE=(alternatedataset,volser)

If there is a problem with the existing logger couple data sets(s),

Issue the following command to change to the logger alternate data set.
```
SETXCF COUPLE,TYPE=LOGR,ACOUPLE=(alternatedataset,volser)
```
Issue the following command to switch the current alternate logger couple data set to be the new primary couple data set.
```
SETXCF COUPLE,TYPE=LOGR,PSWITCH
```

If you are unable to resolve the problem at this point, it may be necessary to stop and restart logger. Before doing this, obtain a dump of logger on the systems that are impacted. See z/OS MVS Diagnosis: Tools and Service Aids for details on obtaining a logger dump.

Start of change See z/OS MVS Diagnosis: Reference for additional information on stopping and restarting the IXGLOGR address space. End of change

To terminate logger, issue the following command. Note that this will cause all active connections on the system to be terminated. Message IXG056I will be issued when the IXGLOGR address space has terminated.

FORCE IXGLOGR,ARM

It may also be necessary to Start of change

terminate

structure connections by issuing the following command. The system will no longer have any type of connection to the structure (strname). Start of change

If no other system has a connection to the structure, XES will deallocate it. End of change

SETXCF FORCE,CON,STRNAME=strname,CONNAME=ALL

Once logger has terminated, it can be restarted by issuing the command S IXGLOGRS. After doing this, it may be necessary to restart applications that were previously connected. Logger will issue an ENF signal to indicate when it is ready to start work.