The trace formatter is a Java™ program
that converts binary trace point data in a trace file to a readable
form. The formatter requires the J9TraceFormat.dat file,
which contains the formatting templates. The formatter produces a
file containing header information about the JVM that produced the
binary trace file, a list of threads for which trace points were produced,
and the formatted trace points with their timestamp, thread ID, trace
point ID and trace point data.
To use the trace formatter on a binary trace file type:
java com.ibm.jvm.format.TraceFormat -Xgcpolicy:metronome <input_file> [<output_file>] [options]
where
<input_file> is
the name of the binary trace file to be formatted, and
<output_file> is
the name of the output file.
If you do not specify an output file, the output file is called <input_file>.fmt.
The size of the heap needed to format the trace is directly proportional
to the number of threads present in the trace file. For large numbers
of threads the formatter might run out of memory, generating the error OutOfMemoryError.
In this case, increase the heap size using the -Xmx option.
Available options
The following options are available with the trace formatter:
- -datdir <directory>
- Selects an alternative formatting template file directory. The
directory must contain the J9TraceFormat.dat file.
- -help
- Displays usage information.
- -indent
- Indents trace messages at each Entry trace point and outdents
trace messages at each Exit trace point. The default is not to indent
the messages.
- -overridetimezone <hours>
- Add <hours> hours to formatted tracepoints,
the value can be negative. This option allows the user to override
the default time zone used in the formatter (UTC).
- -summary
- Prints summary information to the screen without generating an
output file.
- -thread: <thread id>[,<thread
id>]...
- Filters the output for the given thread IDs only. thread
id is the ID of the thread, which can be specified in decimal
or hex (0x) format. Any number of thread IDs can be specified, separated
by commas.
- -uservmid <string>
- Inserts <string> in each formatted tracepoint.
The string aids reading or parsing when several different JVMs or
JVM runs are traced for comparison.