Technical data

42 ServerIron ADX Advanced Server Load Balancing Guide

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Other transparent cache switching options

Removing an interface from a cache group

You can remove an interface from a cache group to assign it to another cache group or to bias its

traffic away from cache servers entirely.

ServerIronADX(config)# interface ethernet 3

ServerIronADX(config-if-3)# no cache-group 1

Syntax: [no] cache-group <group-#>

Assigning an interface to a cache group

To assign an interface to cache group, enter the following command.

ServerIronADX(config)# interface ethernet 3

ServerIronADX(config-if-3)# cache-group 1

NOTE

You must use cache-group 1 to remove no cache-group command.

NOTE

You must create the cache group before you can assign an interface to the group.

Controlling traffic distribution among cache servers

To define how requests are distributed among multiple cache servers within a cache group, you can

use the hash-mask <destination-ip-mask> <source-ip-mask> CLI command at the transparent

cache level.

The ServerIron ADX uses the source and destination IP addresses as hash values. By default, the

destination IP mask is 255.255.255.0, and the source IP mask is 0.0.0.0 which means only first

three octets of destination IP are used to calculate the hash. All other services (known or unknown

port) including SSL uses the predictor which is by default least connection.

The hash mechanism minimizes duplication of content on the cache servers by ensuring that a

particular website is always cached on the same cache server.

NOTE

This is the default mechanism while performing Layer-4 TCS.

NOTE

If you configure the ServerIron ADX for server load balancing in addition to TCS, and the SLB

configuration provides load balancing for your cache servers, then content will be duplicated on the

cache servers as a result of the SLB predictor (load balancing metric). The SLB predictor works

differently from the TCS hash mechanism and assumes that content is duplicated across the load

balanced server.

NOTE

Traffic controlled by policy-based caching on an individual server level is load balanced, whereas

traffic for the other cache servers is partitioned according to the hash feature. Refer to “Policy-based

caching” on page 99.