Technical data

ServerIron ADX Advanced Server Load Balancing Guide 73
53-1002435-03
Content-aware cache switching
2
The port http group-id command indicates the server groups to which the cache server belongs.
The server group is expressed as a pair of numbers, indicating a range of server group IDs. The first
number is the lowest-numbered server group ID, and the second is the highest-numbered server
group ID. For example, if a cache server belongs only to the server group with ID = 1, the last two
numbers in the port http group-id command would be 11. (Note the space between the two
numbers.) If a cache server belongs to server groups 1 through 10, the last two numbers in the
command would be 110. Valid numbers for server group IDs 0 through 1023.
To include a cache server in groups that are not consecutively numbered, you can enter up to four
server group ID pairs. For example, to include a cache server in groups 1 through 5 and 11 through
15, you would enter the following command.
ServerIronADX(config-rs-CacheServer1)# port http group-id 1 5 11 15
You can also specify the server group ID pairs on separate lines by entering commands such as in
the following example.
ServerIronADX(config-rs-CacheServer1)# port http group-id 1 5
ServerIronADX(config-rs-CacheServer1)# port http group-id 11 15
The following commands configure the remaining cache servers in Figure 19 is shown below.
These commands place CacheServer2 in server group ID = 1 (along with CacheServer1) and
CacheServer3 in server group ID = 2.
ServerIronADX(config)# server cache-name CacheServer2 192.168.1.102
ServerIronADX(config-rs-CacheServer2)# port http group-id 1 1
ServerIronADX(config-rs-CacheServer2)# exit
ServerIronADX(config)# server cache-name CacheServer3 192.168.1.103
ServerIronADX(config-rs-CacheServer3)# port http group-id 2 2
ServerIronADX(config-rs-CacheServer3)# exit
Assigning the cache servers to a cache group
To activate content-aware cache switching (as in Figure 19), you create a cache group, assign the
cache servers to that group, and specify a CSW policy to be active for the cache group, such as in
the following example.
ServerIronADX(config)# server cache-group 1
ServerIronADX(config-tc-1)# cache-name CacheServer1
ServerIronADX(config-tc-1)# cache-name CacheServer2
ServerIronADX(config-tc-1)# cache-name CacheServer3
ServerIronADX(config-tc-1)# csw
ServerIronADX(config-tc-1)# csw-policy p1
Syntax: csw
Syntax: csw-policy <policy-name>
Configuring group-failover
When CSW rules are enabled with TCS, the ServerIron ADX tries to select a cache server with a
'server group-id' as specified by the CSW policy. By default, if no cache server is found in the server
group then the request is bypassed to the Internet.
When the group-failover feature is enabled, the ServerIron ADX behaves in the following manner:
• If a cache server is found with the matching server group-id, then the HTTP request is
forwarded to that cache server.