Enabling dynamic tracing for the Data Streamer

For the Data Streamer, you can enable dynamic tracing by using the MVS MODIFY command.

About this task

Trace settings that are changed by using the MVS MODIFY command are not persistent and therefore have no effect when the Data Streamer is restarted.

Procedure

To enable dynamic tracing, IBM® Software Support might require you to run one or more of the following commands:

Table 1. Commands and description
Option	Description
Set trace	To set the trace level for a specific Data Streamer, run the following system command: `F HBODSPRO,APPL=SET,TRACE,level` To set the trace level for specific data streams, run the following system command: `F HBODSPRO,APPL=SET,TRACE,level,DS,loggerName` To set the trace level for a specific component of the Data Streamer, run the following system command: `F HBODSPRO,APPL=SET,TRACE,level,PKG,loggerName` Tip: To enable performance tracing, set `level` to be `PERF` For more information about the values for `level`, `loggerName`, refer to the instructions below this table.
Display trace	To display the root trace level for the Data Streamer, run the following system command: `F HBODSPRO,APPL=DISPLAY,TRACE` To display the trace level for a specific data stream, run the following system command: `F HBODSPRO,APPL=DISPLAY,TRACE,DS,loggerName` If the level is set for the `loggerName`, the Data Streamer prints the trace level directly, otherwise it prints the inherited value for the `loggerName`. To display the trace level for a specific component of the Data Streamer, run the following system command: `F HBODSPRO,APPL=DISPLAY,TRACE,PKG,loggerName` If the level is set for the `loggerName`, the Data Streamer prints the trace level directly, otherwise it prints the inherited value for the `loggerName`. For more information about the values for `loggerName`, refer to the instructions below this table.
Clear trace	To clear all the trace settings of the Data Streamer, run the following system command: `F HBODSPRO,APPL=CLEAR,TRACE` This command sets the value of the root logger level to `EVENT`. It also clears the values for all other loggers so that they inherit their level from the root logger. After the enabled trace settings are no longer needed, use this command to return to the default tracing state. Partial clear is not provided because of the inheritable level for logger. You can override a previous trace value you have set. For example, from the previous `DEBUG` to `EVENT`. After you use the dynamic tracing, you can clear all the tracing settings.

Level

EVENT
The default tracing level. This level provides limited tracing that shows detailed error and warning responses from other applications.
PERF
This level provides some performance information besides event level.
Important: For the Data Streamer, performance tracing data shows the data flow of packets between Threads including Listener, Hopper, Worker and Sender. From the tracing data, you can see the activities of packets between Threads and the size of packets. Performance tracing is not as heavy as regular tracing, but usually it is sufficient to determine an issue.
DEBUG
This level provides moderate tracing that shows values of significant variables at key points in the code path.

LoggerName

If the logger type is DS for a specific data stream, the loggerName can be
- dataSourceType
- dataSourceType, dataSourceName
The dataSourceType and the dataSourceName have the same meanings as that of a data stream in the Configure data stream window in the Configuration Tool.
The following example shows how to set debug on CICS® User Messages:
```
F HBODSPRO,APPL=SET,TRACE,DEBUG,DS,zOS-CICS-MSGUSR
```
The following example shows how to set debug on a CICS User Messages data stream named GLASCICS:
```
F HBODSPRO,APPL=SET,TRACE,DEBUG,DS,zOS-CICS-MSGUSR,GLASCICS
```
If there are multiple data streams of one data source type in the policy. The dataSource Type affects all the data streams with this data source type. The dataSourceType, dataSourceName only affects specific data stream.
If the logger type is PKG for a specific component, the loggerName is provided by IBM Software Support.