BEA WebLogic Server Tuning Guide

3.17 Reducing the Minimum Listen Queue Size and Acknowledgement Delay

Interval

By default, the listen queue sizes for the TCP/IP V6 stack is set to128 and the acknowledgement delay interval is set

to 20 milliseconds.

Here is an extract from the SCF command output that shows this. The TCP6SAM process name is $ZZTCP by

default.

1-> info mon $ZZTCP.#ZPTM0,detail

TCPIPV6 Detailed Info MON \HOST.$ZZTCP.#ZPTM0

*TCP Send Space......... 61440D *TCP Receive Space...... 61440D

*UDP Send Space......... 9216D *UDP Receive Space...... 42080D

*Delay Ack Time......... 20 *Delay Ack.............. ON

*Keep Alive Idle........ 75 *Keep Alive Retry Cnt... 8

*Keep Alive Interval.... 75 QIO Limit.............. 100%

*Host ID ............... 0.0.0.0

*Host Name ............. host.domain

Program Filename ...... \HOST.$SYSTEM.SYSnn.TCP6MON

*Debug.................. OFF

*Full Dump.............. ON

*All Nets Are Local..... OFF

*TCP Compat 42.......... ON

*EXPAND Security........ OFF

*TCP Path MTU........... ON

*TCP Time Wait.......... 60

Trace Status........... OFF

Trace Filename ........

*RFC1323 Enable ........ ON

*TCP Init Rexmit Timeout 1000 ms

*TCP Min Rexmit Timeout. 1000 ms

*TCP Listen Queue Min... 128

*Initial TTL............ 60

*Min-Ephemeral-Port..... 49151

*Max-Ephemeral-Port..... 65535

*Max-Priv-Port.......... 1023

*TCPCWNDMULTIPLIER...... 2

*TCP SACK............... OFF

*NONSHAREDOUTDIST....... OFF

*Family................. INET

Total LNPs Configured.. 0

*TCP Max Rexmit Time.... 64000 ms

*TCP Max Rexmit Count... 12

The two highlighted values show the defaults. It is suggested that both these values be set to 5. For details on

altering these values, refer to the TCP/IP V6 configuration manuals.