Investigating the logging and tracing output for the application
server is an excellent way to observe performance, diagnose problems,
and gain a general understanding of how the application server is
working within your environment. The expected output locations for
logging and trace information can be different depending on the operating
system on which the application server is running.
![[AIX Solaris HP-UX Linux Windows]](../../dist.gif)
Logging and tracing output streams are
directed as follows for distributed and IBM i operating systems:
Table 1. Log and trace output for distributed and IBM i
Log or trace stream |
Expected output |
Java trace |
Trace.log. You must have tracing enabled. |
Java logs |
- Trace.log, when you enable tracing.
- Activity.log. The Activity.log file is also directed to the Showlog
output.
- SystemOut.log
|
System.out stream |
|
System.err stream |
SystemErr.log |
cout (the C or C++ output stream) |
Native stdout |
cerr (the C or C++ error stream) |
Native stderr |

![[z/OS]](../../ngzos.gif)
When the application server is installed on z/OS,
the logging and output streams are directed as follows:
Table 2. Log and trace output for z/OS
Log or trace stream |
Expected output |
Tracing (both native trace and Java tracing) |
SYSPRINT Avoid trouble: Trace information,
which includes events at the Fine, Finer and Finest levels, will be
written only to this output. If you do not enable diagnostic trace,
setting the log detail level to Fine, Finer, or Finest does not effect
the logged data. gotcha
|
Tracing level equal to the Audit level |
Transformed into write-to-operator (WTO) output
to the hard copy logging stream |
Tracing level equal to or above the Detail level |
SYSOUT or your configured error stream |
Messages, including native messages and most
trace messages |
SYSOUT or your configured error stream |
System.out |
SYSPRINT |
System.err |
SYSPRINT |
When considering the direction of log and trace streams, keep
in mind the following acronyms and abbreviations:
- cerr
- C or C++ error steam
- cout
- C or C++ output steam
- DD
- Data Description statements
- HFS
- HTTP File Server
- JCL
- Java Control Language
- JES
- Java error stream
- MVS
- Multiple Virtual Storage
- WTO
- Write-to-operator
- WTOR
- Write-to-operator with reply
