Technical data

80 Brocade ServerIron ADX Advanced Server Load Balancing Guide
53-1003441-01
Content-aware cache switching
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The first time a client requests a URL that ends with "gif" (for example, /home/main/banner.gif) the
following events take place.
1. Because the URL ends with "gif", the CSW policy on the ServerIron ADX directs the request to
one of the cache servers in Server Group ID=1.
2. When a server group consists of more than one cache server, the ServerIron ADX uses a
hashing algorithm to select one of the cache servers, and directs the request to the selected
cache server.
3. Because this is the first time the content is requested, the selected cache server does not have
the content stored, so the cache server retrieves it from the Internet.
4. The cache server receives the content, caches it, and sends it to the requesting client.
The next time a client requests the content, the following events take place.
1. Because the URL begins with "gif", the CSW policy directs the request to one of the cache
servers in Server Group ID=1.
2. The ServerIron ADX hashes the URL string, selecting the same server it selected previously.
3. This time the cache server has the content and does not have to go to the Internet to get it; it
sends the cached content to the requesting client.
Setting up content-aware cache switching consists of the following steps.
1. Enabling TCS on the ServerIron ADX
2. Setting up CSW policies
3. Configuring the cache servers
4. Assigning the cache servers to a cache group
Enabling TCS
To enable TCS on all interfaces (globally) of the ServerIron ADX shown in Figure 21, enter the
following command.
ServerIronADX(config)#ip policy 1 cache tcp 80 global
Syntax: ip policy index cache | normal | high tcp | udp tcp/udp-portnum global | local