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

Tuning TCP Buffering

If you are seeing unpredictable intermittent slowdowns in network response from a consistently loaded server, investigate setting the sq_max_size parameter by adding the following line to the /etc/system file:

set sq_max_size=512

This setting adjusts the size of the sync queue, which transfers packets from the hardware driver to the TCP/IP protocol driver. Using the value of 512 allows the queue to accommodate high volumes of network traffic without overflowing.