Basic mode and HPEL mode

Two modes of logging and tracing exist in WAS v9: basic mode and High Performance Extensible Logging (HPEL) mode. IBM recommends using the HPEL log and trace infrastructure.

We view HPEL log and trace information using the logViewer.

Once HPEL mode is enabled the JVM logs (SystemOut.log and SystemErr.log), the trace log (trace.log), and the service log (activity.log) are no longer written to. Instead, log and trace content is written to a log data or trace data repository in a proprietary binary format and, if configured, to a text log file. Disabling the writing of the text log file results in the largest possible performance benefit of HPEL.

Source	Basic mode	HPEL mode	To view
System.out	SystemOut.log trace.log	logdata/*.wbl TextLog_<timestamp>.log	For logdata use logViewer, with optional filtering, to render log data repository as readable text, then use any text editor. TextLog available only if enabled. Use any text editor
System.err	SystemErr.log	Same as System.out	Same as System.out
java.util.logging	SystemOut.log activity.log trace.log	Same as System.out	For levels DETAIL and above. Same as System.out
java.util.logging	trace.log	tracedata/*.wbl TextLog_<timestamp>.log	For levels below DETAIL. For tracedata use logViewer, with optional filtering, to render trace data repository as readable text, then use any text editor. TextLog available only if enabled. Use any text editor
native cout	native_stdout.log	native_stdout.log	Any text editor
native cerr	native_stderr.log	native_stderr.log	Any text editor

The following table describes the MBean services:

Basic mode MBeans	HPEL mode MBeans	HPEL MBean Descriptions
RasLoggingServiceMBean	RasLoggingServiceMBean	Provide JMX Notification
	HPELLogDataServiceMBean	Configure the log repository such as location, retention policy, out of space behavior, buffering, and file switching
	HPELTraceDataServiceMBean	Configure the trace repository such as location, retention policy, out of space behavior, buffering, and file switching
	HPELTextLogServiceMBean	Configure the text log such as location, retention policy, out of space behavior, buffering, file switching, and SystemErr or SystemOut format
TraceServiceMBean	HPELControlServiceMBean	Configure trace specification levels, and provides access to log and trace repository content