Sun Java System Web Server 6.1 SP11 Performance Tuning, Sizing, and Scaling Guide

Library configuration

To enable the plugin, you must modify magnus.conf manually. This should look something like this:

Init fn="load-modules" funcs="init-resonate"
shlib="server_root/bin/https/lib/libloadbal.so"
Init fn="init-resonate" ThreadPool="sleep" 
EventExePath="/tools/ns/bin/perl5" LateInit="yes" 
CmdLow="/opt/SUNWwbsvr/plugins/loadbal/CmdLow.pl" 
CmdHigh="/opt/SUNWwbsvr/plugins/loadbal/CmdHigh.pl"

The init-resonate function can take the following parameters:

Table 3–1 init-resonate Parameters

Parameter  

Description  

ThreadPool

Name of the thread pool to monitor. 

Aggressive

If set to TRUE, this argument causes the plugin to use the pool thread count rather than the queue thread count.

PollTime

How frequently to check the thread status. The default is 2000 milliseconds. 

HighThreshold

Defines the queue size/# of threads where HighCmd is executed to increase load on the server. The default is 4096.

LowThreshold

Defines the queue size/# of threads where the LowCmd is executed to decrease load on the server. The default is 1.

EventExePath

Pointer to the script program you want to run (for instance, /usr/bin/perl or /bin/sh). Defaults to perl or perl.exe, depending on the platform.

CmdLow

Pointer to the script to be run when the LowThreshold is met.

ArgsLow

Arguments to send to CmdLow.

CmdHigh

Pointer to the script to be run when the HighThreshold is met.

ArgsHigh

Arguments to send to CmdHigh.


Note –

You must specify LateInit="yes" when loading this module. The module creates a monitoring thread, and this monitoring thread must start after ns-httpd has started.


If you set LogVerbose on in magnus.conf, the error log contains information on how the plugin is configured and when it is invoked.

A sample of the information in the error log is shown below:

[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin watching 
thread pool sleep
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin 
aggressive setting is FALSE
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin poll time 
set to 2000
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin 
HighThreshold set to 5
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin 
LowThreshold set to 1
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin event 
executable path set to /tools/ns/bin/perl5
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin low 
command set to /opt/SUNWwbsvr/plugins/loadbal/CmdLow.pl
[12/Jun/2003:09:36:35] verbose (20685): Resonate plugin high 
command set to /opt/SUNWwbsvr/plugins/loadbal/CmdHigh.pl

This is what the log entries will look like when LogVerbose on is set and the plugin is activated:

[12/Jun/2003:09:40:12] verbose (20699): Resonate plugin reducing load.
 [12/Jun/2003:09:40:14] verbose (20699): Resonate plugin reducing load.
 [12/Jun/2003:09:40:16] verbose (20699): Resonate plugin reducing load.
 [12/Jun/2003:09:40:18] verbose (20699): Resonate plugin reducing load.
 [12/Jun/2003:09:40:20] verbose (20699): Resonate plugin reducing load.
 [12/Jun/2003:09:40:30] verbose (20699): Resonate plugin increasing load.