Nortel Web OS 10.0, Application Manual

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Web OS 10.0 Application Guide
Chapter 6: Server Load Balancing
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How Server Load Balancing Works
In an average network that employs multiple servers without server load balancing, each server
usually specializes in providing one or two unique services. If one of these servers provides
access to applications or data that is in high demand, it can become overutilized. Placing this
kind of strain on a server can decrease the performance of the entire network as user requests are
rejected by the server and then resubmitted by the user stations. Ironically, over-utilization of
key servers often happens in networks where other servers are actually available.
The solution to getting the most from your servers is SLB. With this software feature, the
switch is aware of the services provided by each server. The switch can direct user session traf-
fic to an appropriate server, based on a variety of load-balancing algorithms.
Figure 6-1 Traditional Versus SLB Network Configurations
To provide load balancing for any particular type of service, each server in the pool must have
access to identical content, either directly (duplicated on each server) or through a back-end
network (mounting the same file system or database server).
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