IBM User Guide for Java V7 on Windows > Troubleshooting and support > Using diagnostic tools > Tracing Java applications and the JVM > Controlling the trace > Detailed descriptions of trace options

buffers=nnnk|nnnm[,dynamic|nodynamic]

You can modify the size of the buffers to change how much diagnostics output is provided in a snap dump. This buffer is allocated for each thread that makes trace entries.

The trace option can be specified in two ways:

• buffers=dynamic|nodynamic
• buffers=nnnk|nnnm[,dynamic|nodynamic]

If external trace is enabled, the number of buffers is doubled; that is, each thread allocates two or more buffers. The same buffer size is used for state and exception tracing, but, in this case, buffers are allocated globally. The default is 8 KB per thread.

The dynamic and nodynamic options have meaning only when tracing to an output file. If dynamic is specified, buffers are allocated as needed to match the rate of trace data generation to the output media. Conversely, if nodynamic is specified, a maximum of two buffers per thread is allocated. The default is dynamic. The dynamic option is effective only when you are tracing to an output file.

Note: If nodynamic is specified, you might lose trace data if the volume of trace data that is produced exceeds the bandwidth of the trace output file. Message UTE115 is issued when the first trace entry is lost, and message UTE018 is issued at JVM termination.

Examples

• Dynamic buffering with increased buffer size of 2 MB per thread:

  -Xtrace:buffers=2m

  or in a properties file:

  buffers=2m

• Trace buffers limited to two buffers per thread, each of 128 KB:

  -Xtrace:buffers={128k,nodynamic}

  or in a properties file:

  buffers=128k,nodynamic

• Trace using default buffer size of 8 KB, limited to two buffers per thread:

  -Xtrace:buffers=nodynamic

  or in a properties file:

  buffers=nodynamic

Parent: Detailed descriptions of trace options

Error 404 - Not Found

The document you are looking for may have been removed or re-named. Please contact the web site owner for further assistance.