Trace logging

All trace log data sets are tracked in an online trace directory. The HT view displays these data sets and allows online access with a simple line command, whether the trace was written the same day, last night, a year ago, or even on another system. This provides these benefits:

• Data from completed traces is saved in the trace logs so that no data is lost during system interruptions.
• The older data from an active trace with multiple log data sets can be accessed through this application.
• Online administration of the trace logs simplifies the tracking of which traces are valuable enough to keep for later reporting and which should be deleted after review. An additional option allows the submission of a batch job to print any trace.
• Traces can be kept as transaction profiles for later comparisons after application or system changes that may affect performance. A trace of an application on the development system can be compared to the same trace on production to easily spot access path changes or performance degradation.
• Very large applications can be traced.

The logging facility also enables tracing of long-running applications without loss of data because of online buffer limitations. However, be aware that data might be lost if wrapping is on and there are not enough preallocated log data sets to hold all the data.