4.5.2 Collocated servers
Load Balancer can reside on the same machine as a Web server to which it is distributing incoming requests. This is commonly referred to as collocating a server. Collocated servers keep initial costs down but allow evolving to a more complex configuration, such as a dedicated server for Dispatcher or even a high availability solution. Collocation is also supported for CBR.
Collocation applies to the Dispatcher and Site Selector components.
WebSphere Edge Components V6 added support for collocation on Windows systems for the MAC forwarding method, as mentioned in 4.9, WebSphere Edge Components V6 new features.
To use collocated servers in a Linux environment, apply an arp patch which varies for the different kernel versions of Linux. This patch is also necessary for non-collocated balanced servers.
A collocated Web server competes for resources with Load Balancer during times of high traffic. However, in the absence of overloaded machines, using collocated servers offers a reduction in the total number of machines necessary to set up a load-balanced site.
See also...
Load Balancer Administration Guide v6, GC31-6858
