Tracer — Adjusting the file buffer size

During Tracer operation, the system by default saves unprocessed events in a temporary file that is limited to 500 items. In some tracing situations, this can cause the display to lag behind the processing being traced, or cause the Tracer display to be incomplete or fail.

If the buffer overflows the limit of 500 items, Tracer processing ends. To avoid this condition, you can cause the system to save more events in the temporary file. (To prevent runaway or looping operations, the disk file mechanism also has a maximum size; the default is 50,000 unprocessed events.

How to configure

To adjust the size of the Tracer file buffer:

1. Edit the prconfig.xml file to contain two lines:

<env name="tracer/queue/type" value="file" />
<env name="tracer/queue/file/limit" value="nnnnn" />

where nnnnn is a non-negative integer. If you omit the second line, the default limit is 50,000 events.

2. Stop and restart (or redeploy if necessary) the server node to have the changes take effect. Each Tracer session on the node uses a separate file in the temporary file directory on the server.

To allow a file with no limit on the number of events, set the value in the second line to 0. Use this setting only when necessary, as an infinite loop in program execution might cause the file to consume all free space on the disk.

Benefits

This option has two benefits:

• When this option is configured, the buffer for unprocessed events is much larger. The Tracer is unlikely to fail because unprocessed events have caused the buffer to overflow.
• When you click the Save option () on the Tracer panel, the system saves processed Tracer output as a detailed XML file rather than a summary Comma-Separated-Values file.

Notes

1. To use an in-memory buffer rather than the file buffer, change the value for the type from "file" to "memory":

<env name="tracer/queue/type" value="memory" />

2. Ensure that the disk device holding temporary files has available space for this and other files produced by Process Commander operations. If the disk is full or the Tracer is unable to open a temporary file, the user may be prompted to restart the Tracer, which then falls back to the in-memory buffer.

	temporary file
	Troubleshooting — Tracer

Using the Tracer