Url hashing for web cache redirection, Url hashing for web cache redirection 406 – Nortel Networks WEB OS 212777 User Manual

Page 406

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Web OS 10.0 Application Guide

406

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Chapter 15: Content Intelligent Switching

212777-A, February 2002

7.

Add the defined string IDs to configure the real server(s) to handle the appropriate load
balance string(s).

where ID is the identification number of the defined string.

N

OTE

If you don’t add a defined string (or add the ID 1), the server will handle any request.

URL Hashing for Web Cache Redirection

By default, hashing algorithms use the source IP address and/or destination IP address
(depending on the application area) to determine content location. For example, firewall load
balancing uses both source and destination IP addresses, WCR uses only the destination IP
address, and SLB uses only the source IP address.

Hashing is based on the URL, including the HTTP Host header (if present), up to a maximum
of 255 bytes. You can optimize “cache hits” by using the hashing algorithm to redirect client
requests going to the same page of an origin server to a specific cache server.

For example the switch could use the string “nortelnetworks.com/products/180/” for hashing
the following request:

GET http://products/180 / HTTP/1.0

HOST:www.nortelnetworks.com

To configure the switch for WCR based on a hash key, use the following procedure:

1.

Configure basic SLB.

Before you can configure header-based cache redirection, ensure that the switch has already
been configured for basic SLB (see

“Server Load Balancing” on page 117

) with the following

tasks:

n

Assign an IP address to each of the real servers in the server pool.

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Define an IP interface on the switch.

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Define each real server.

n

Assign servers to real server groups.

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Define virtual servers and services.

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Configure the load-balancing algorithm to

hash

or

minmiss

.

>> # /cfg/slb/real 2/layer7/addlb

<ID>

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