Sun Java System Web Server 7.0 Update 4 Performance Tuning, Sizing, and Scaling Guide

Tuning MMapSessionManager (UNIX/Linux)

The following example describes the effect on process size when configuring the persistence-type="mmap" using the manager-properties properties. For more information, see MMap Session Manager (UNIX Only) in Sun Java System Web Server 7.0 Update 4 Developer’s Guide to Java Web Applications.

maxSessions = 1000
maxValuesPerSession = 10
maxValueSize = 4096

This example creates a memory mapped file of size 1000 X 10 X 4096 bytes, or ~40 MB. As this is a memory mapped file, the process size will increase by 40 MB upon startup. The larger the values you set for these parameters, the greater the increase in process size.