Sun GlassFish Enterprise Server v2.1.1 Performance Tuning Guide

Tuning LogBufferSize

Begin with the default value. Look for HIGH LOAD informational messages in the history files. All the relevant messages will contain tuple log or simply log, and a description of the internal resource contention that occurred.

Under normal operation the log is reported as 70 to 80% full. This is because space reclamation is said to be “lazy.” HADB requires as much data in the log as possible, to recover from a possible node crash.

Use the following command to display information on log buffer size and use:

hadbm resourceinfo --logbuf

For example, output might look like this:

Node No.     Avail         Free Size
0            44            42
1            44            42

The columns in the output are: