Configuring a Weighted Load Balancing Mechanism for the v4.0 HTTP Plugin
 Technote (FAQ)
 
Problem
The WebSphere® Application Server v4.0 HTTP Plugin supports two clone selection policies; round robin and random. This document describes a technique that will cause the HTTP Plugin to select one clone more often than others, giving the clone a higher weight in the clone selection phase of request handling.
 
Cause
You can cause the Web server plug-in to route more requests to a particular clone in your configuration than it does to others.
 
Solution
The v4.0 HTTP Plugin will use the server group list defined in the plugin-cfg.xml to route requests. With a round robin selection policy defined, the plugin will simply route the current request to the next server defined in the server group list. The plugin will not load-balance across transports defined for a single server. If you would like one clone or transport selected more often than others, simply define the clone or transport multiple times. The transport or clone will naturally be selected more often.

For example the ServerGroup could look like this:

<ServerGroup name="Servers">

<Server name="Server1">
<Transport Hostname="Host_A" Port=9081 Protocol=HTTP/>
</Server>

<Server name="Server2">
<Transport Hostname="Host_A" Port=9081 Protocol=HTTP/>
</Server>

<Server name="Server3">
<Transport Hostname="Host_A" Port=9081 Protocol=HTTP/>
</Server>

<Server name="Server4">
<Transport Hostname="Host_B" Port=9081 Protocol=HTTP/>
</Server>

</ServerGroup>
   

This requires that the plugin-cfg.xml be manually maintained in order to keep the configuration in tact.
                                                           
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Plug-in
Operating system(s): HP-UX
Software version: 4.0.7
Software edition:
Reference #: 1104515
IBM Group: Software Group
Modified date: Jul 30, 2004