Technical data

74 ServerIron ADX Advanced Server Load Balancing Guide

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Content-aware cache switching

• If a cache server with the matching server group-id is not found, but a default CSW rule with

forward action is specified, then the HTTP request is forwarded to a cache server defined

inside the default rule.

• If a cache server with the matching server group-id is not found, and a default CSW rule with

forward action is not specified, then the HTTP request is forwarded to any available cache

server within the cache-group.

This process is demonstated in the configuration described in: “group-failover example”.

To enable group failover, enter commands such as the following:

ServerIronADX(config)#server cache-group 1

ServerIronADX(config-tc-1)#group-failover

ServerIronADX(config-tc-1)#

Syntax: [no] group-failover

group-failover example

Given the following TCS configuration:

ServerIronADX(config)# csw-policy policy1

ServerIronADX(config-csw-policy1)# match rule1 forward 1

ServerIronADX(config-csw-policy1)# default forward 2

ServerIronADX(config-csw-policy1)# exit

ServerIronADX(config)# server cache-name Cache1 10.1.1.11

ServerIronADX(config-rs-Cache1)# port http url "HEAD /"

ServerIronADX(config-rs-Cache1)# port http group-id 1 1

ServerIronADX(config)# server cache-name Cache1 10.1.1.12

ServerIronADX(config-rs-Cache1)# port http url "HEAD /"

ServerIronADX(config-rs-Cache1)# port http group-id 2 2

ServerIronADX(config)# server cache-name Cache1 10.1.1.13

ServerIronADX(config-rs-Cache1)# port http url "HEAD /"

ServerIronADX(config-rs-Cache1)# port http group-id 3 3

ServerIronADX(config)#server cache-group 1

ServerIronADX(config-tc-1)# cache-name cache1

ServerIronADX(config-tc-1)# cache-name cache2

ServerIronADX(config-tc-1)# cache-name cache3

ServerIronADX(config-tc-1)# spoof-support

ServerIronADX(config)# csw-policy policy1

Suppose the client sends an HTTP request to the remote host: “abc.com”. The ServerIron ADX will

then forward the request to 'cache1' due to the configured csw-policy: 'policy1'. If cache1 goes

down, subsequent requests to “abc.com” will then be directed to the Internet. The default rule will

not be evaluated here since a csw-rule match was already found. The default rule will only be

evaluated when the incoming request does not match against any configured csw-rule.

ServerIronADX(config)# server cache-group 1

ServerIronADX(config-tc-1)# group failover