Technical data

80 ServerIron ADX Advanced Server Load Balancing Guide

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Cache persistence using URL hashing

ServerIronADX# clear server keep-alive statistics

Syntax: clear server keep-alive statistics

Cache persistence using URL hashing

The ServerIron ADX enables traffic distribution among cache servers in a TCS setup after

inspecting and hashing based on the request URL. This enables cache persistence based on the

requested URL and minimizes duplication of content among multiple cache servers.

The hashing can be done on a complete URL or a portion of the URL. The following choices are

available:

• Complete URL

• Path only

• Path and parameters only

• Host only

• Host and path only

Additionally, you can identify a sub-portion of either the complete URL or the host portion of the

URL to perform the hashing on.

The hashing method is specified within a CSW policy definition as an action to be taken when a

match is made.

NOTE

In previous versions of the ServerIron ADX software, this feature was configured using the csw-hash

url command within the server cache-group configuration. This command is no longer available.

The following example directs the ServerIron ADX to hash on the complete URL when the conditions

in the “r1” CSW rule is met.

NOTE

Because hash-persist action is a secondary action, you must add a forward action as shown in the

following example, before adding a hash-persist action.

ServerIronADX(config)# csw-policy p1

ServerIronADX(config-csw-p1)# match r1 forward 1

ServerIronADX(config-csw-p1)# match r1 hash-persist url complete

Syntax: [no] hash-persist url <method>

The <method> variable can be one of the following:

• complete

• path-only

• path-and-parameters - default value

• host-only

• host-and-path

For example, when a client tries to connect to http://login.yahoo.com/config/mail?.src=ym, the

http requests can come in two different ways: