The SpringSource dm Server’s logging (trace) support serves two main purposes:
System.out and System.err.
These files are
intended for use by application developers and system administrators.
By default, the dm Server trace file is called
$SERVER_HOME/serviceability/logs/dm-server/log_i.log,
and, again by default, the application trace files are called
$SERVER_HOME/serviceability/logs/application_name/log_i.log,
where application_name is automatically set by dm Server for each application artifact installed and run
(it is a combination of the artifact name and the version).
The index i varies from 1 to 4, on a rolling basis, as each log file exceeds 10Mb.
Entries in trace files are by default of the form <timestamp> <thread-name> <source> <level> <entry-text>. For example:
[2008-05-15 09:09:46.940] server-dm-2 org.apache.coyote.http11.Http11Protocol I Initializing Coyote HTTP/1.1 on http-48080
although this format is completely determined by the Logback configuration file serviceability.xml.
SpringSource dm Server provides advanced support for capturing and tracing application-generated output by automatically separating trace output on a
per-application basis and will also capture any System.out and System.err output.
SpringSource dm Server uses SLF4J interfaces to Logback, and the root logger (by default) captures all logging output
and appends it to the application-specific trace files as described above.
To modify this, define application-specific loggers in the serviceability.xml file in the normal way.
System.out and System.err output from applications is, by default, captured in the
application’s trace file.
This happens because the output streams are intercepted and written to the loggers named
System.out at INFO level
and System.err at ERROR level respectively.
Since there are no explicit loggers defined with these names in the serviceability.xml file,
this output is logged by the root logger (which captures INFO level and above).
The trace entries for System.out and System.err
output are of the form:
[2008-05-16 09:28:45.874] server-tomcat-thread-1 System.out I Hello world! [2008-05-16 09:28:45.874] server-tomcat-thread-1 System.err E Hello world!
The third column indicates where the output came from (System.out or System.err)
and, as indicated by the fourth column, System.out is traced at the info level, and System.err is
traced at the error level.
To over-ride this behaviour, simply define explicit loggers named System.out
and/or System.err in the configuration file to send this output to an appender of your choice.
Be aware that all applications’ output streams will be caught by these loggers, and that a sifting appender might be useful to separate them.