Examine a user application with transaction tracing
Use transaction tracing to identify problem trends occurring with a user application, transaction, or program. Transaction tracing consists of data collection and views.
Transaction tracing overview
Views and commands are provided with which you can start, stop, and manage traces; query and view trace data; and manage trace logs.
When you trace a transaction, you can:
Define common detail-trace filtering parameters
The filters are applied to every detail trace instance for a given IMS environment. Filters can limit which DL/I calls are traced by basing the trace on the elapsed time of the call, status code, or return codes. This can:
- Ensure that problematic calls are traced (and not lost due to a full buffer)
- Limit the volume of DL/I call details to review
- Reduce detail buffer size requirements
- Qualify a specific by workload selection or by exception filters to limit the trace (for example, by database name or high elapsed time)
- Set automatic start and stop times for the trace when you think the most activity will occur
- Use views to:
- Query a trace to find problematic transactions
- See transaction trace entries
- Expand to see summarized trace data or detailed trace events for a selected transaction
There are different types of transaction traces and different types of transaction trace views.
When you request a trace, you can also ask for the trace data to be recorded to external VSAM data sets, called trace log data sets, for later viewing. Trace log data sets can store summary and detail traces.
Trace logging provides the following capabilities:
Log data sets for each trace request
Each trace request can be assigned its own log data sets, which allows dynamic application traces to be managed separately from system-wide, continuous workload traces, or system exception traces.
Flexible space management
Each trace can be logged to single or multiple data sets either manually preallocated or dynamically allocated and managed by the transaction trace administration views.
User-selected logging options
A trace can be logged by using option defaults or by specifying values for all of the options for complete control.
Viewing of active trace data online
The transaction trace information views (ITAL* and ITAS*) can be used to see the current data from an active trace or from one being logged to a data set.
Viewing of historical trace data at any time
The History Trace (HT) view displays the data sets tracked in the trace directory. You can view the data recorded in these data sets whether the trace was written the same day, last night, a year ago, or even on another system.
Tracing of very large applications
Long-running applications can be traced without loss of data because of online trace storage buffer limitations.
This section contains the following topics: