WebSphere Application Server traces can be extremely helpful in detecting and diagnosing problems.
By properly setting trace options, you can capture the information needed to detect problems without significant performance overhead.
You should check your WebSphere for z/OS tracing options to ensure that ras_trace_defaultTracingLevel=0 or 1, and that ras_trace_basic and ras_trace_detail are not set.
The default settings of ras_trace_BufferCount=4 and ras_trace_BufferSize=1M should perform sufficiently for most applications.
com.ibm.ejs.*=all=disable com.ibm.ws390.orb=all=disableEnsure that both lines are set to =disable or delete the two lines altogether.