Technical data

84 Brocade ServerIron ADX Advanced Server Load Balancing Guide
53-1003441-01
Content-aware cache switching
2
ServerIron(config)#server cache-name Cache1 10.1.1.12
ServerIron(config-rs-Cache1)#port http url "HEAD /"
ServerIron(config-rs-Cache1)#port http group-id 2 2
ServerIron(config)#server cache-name Cache1 10.1.1.13
ServerIron(config-rs-Cache1)#port http url "HEAD /"
ServerIron(config-rs-Cache1)#port http group-id 3 3
ServerIron(config)#server cache-group 1
ServerIron(config-tc-1)#cache-name cache1
ServerIron(config-tc-1)#cache-name cache2
ServerIron(config-tc-1)#cache-name cache3
ServerIron(config-tc-1)#spoof-support
ServerIron(config)#csw-policy policy1
Suppose the client sends an HTTP request to the remote host: “example2.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 “example2.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.
ServerIron(config)#server cache-group 1
ServerIron(config-tc-1)#group failover
When group-failover is enabled: if cache1 goes down, then the request is matched against the
default rule, and directed to 'cache2'. If cache2 was also down, then the request is sent to any
available cache server defined under 'cache-group 1' (such as 'cache3' in this example).
Configuring policies for dynamic content
For dynamic web pages such as Active Server Pages, it may be preferable not to cache the content.
You can configure CSW policies on the ServerIron ADX that cause requests for these kinds of pages
to bypass the cache servers and go directly to the Internet.
In addition, the ServerIron ADX examines directives in the HTTP 1.0 or 1.1 header to determine
whether a request should be sent to the cache servers or to the Internet. When this feature is
enabled (the default), a request is sent to the origin server regardless of the URL string if one of the
following is true:
• The request contains a pragma:no-cache header (HTTP 1.0 requests).
• The Cache-Control header in the request contains a no-cache directive (HTTP 1.1 requests).