First Failure Data Capture (FFDC) records are stored in human readable text files with names that start with the prefix xmsffdc. Trace files are binary and can be formatted. Trace file names start with the prefix xms.
XMS creates FFDC records and trace files in the current working directory, unless you specify an alternative location by configuring an XMS environment variable as described below.
To configure trace for an XMS C or C++ application, set the following XMS environment variables before running the application:
Environment variables | Default | Settings | Meaning |
---|---|---|---|
XMS_TRACE_ON | Not applicable | normal | Selected components are traced. |
full | All components are traced. | ||
partial | A comma separated list of component identifiers to trace. For example, "partial,osa,cal" only traces XMS components gxiosa and gxical. Use full trace to show the components that can be traced. | ||
XMS_TRACE_FILE_PATH | Current working directory | /dirpath/ | The directory path that trace and FFDC records
are written to. XMS creates FFDC and trace files in the current working directory, unless you specify an alternative location by setting the environment variable XMS_TRACE_FILE_PATH to the fully qualified path name of the directory where you want XMS to create the FFDC and trace files. You must set this environment variable before you start the application that you want to trace, and you must make sure that the user identifier under which the application runs has the authority to write to the directory where XMS creates the FFDC and trace files. |
XMS_TRACE_FILE_SIZE | 200000 | integer | The maximum size that XMS product trace can grow to (in kilobytes), that is, 10 represents 10,000 bytes. |
XMS_TRACE_FILE_NUMBER | 4 | integer | The number of files that can be used to store trace records. (200000 / 4 = 50000 bytes per file.) |
To configure trace dynamically, use the executable gxisc. You can use gxisc to enable and disable trace in a running XMS C or C++ application, and to modify the trace size. You must run gxisc on the same machine as the XMS application.
To invoke gxisc, use the process id of the XMS application for which you want to alter the trace configuration, as shown in the example below.
gxisc 1234 <enter> display all <enter> alter trace(enabled) tracesize(100) <enter> help <enter> alter trace(disabled) <enter> alter <enter> end gxisc <enter> alter pid(1234) trace(enabled) <enter> end cat a.file <enter> alter pid(1234) trace(enabled) end cat a.file | gxisc <enter> cat b.file <enter> alter trace(disabled) tracesize(1000) end cat b.file | gxisc 1234 <enter>
To minimize processing and disk overheads at runtime, XMS outputs trace in a binary format into one or more trace files with the extension .trc. You can format trace files by using the executable gxitrcfmt, as shown in the following example:
gxitrcfmt xms01234.trc
A formatted file has the suffix txt, for example:
cat xms01234.trc.txt