Nortel Networks WEB OS 212777 - Manual (Page 383)

Web OS 10.0 Application Guide
Chapter 15: Content Intelligent Switching n 383
212777-A, February 2002
Cookie-Based Preferential Load Balancing
Cookies can be used to provide preferential services for customers, ensuring that certain users
are offered better access to resources than other users when site resources are scarce. For
example, a Web server could authenticate a user via a password and then set cookies to identify
them as “Gold,” “Silver,” or “Bronze” customers. Using cookies, you can distinguish individu-
als or groups of users and place them into groups or communities that get redirected to better
resources and receive better services than all other users.
N OTE – Cookie-based persistent load balancing is described in Chapter 16, “Persistence .”
Cookie-based preferential services enable the following support:
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Redirect higher priority users to a larger server or server group.
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Identify a user group and redirect them to a particular server.
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Serve content based on user identity.
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Prioritize access to scarce resources on a Web site.
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Provide better services to repeat customers, based on access count.
Clients that receive preferential service can be distinguished from other users by one of the fol-
lowing methods:
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Individual User
Specific individual user could be distinguished by IP address, login authentication, or per-
manent HTTP cookie.
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User Communities
Some set of users, such as “Premium Users” for service providers who pay higher mem-
bership fees than “Normal Users” could be identified by source address range, login
authentication, or permanent HTTP cookie.
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Applications
Users could be identified by the specific application they are using. For example, priority
can be given to HTTPS traffic that is performing credit card transactions versus HTTP
browsing traffic.
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Content
Users could be identified by the specific content they are accessing.
Based on one or more of the criteria above, you can load balance requests to different server
groups.