Technical data

82 Brocade ServerIron ADX Advanced Server Load Balancing Guide
53-1003441-01
Content-aware cache switching
2
NOTE
As the diagram in Figure 21 illustrates, there is only one cache server in Server Group ID = 2. Even
so, the match command must refer to a server group rather than an actual cache server. Server
groups can consist of one or more cache servers.
NOTE
By default, if no cache server is found in the server group then the request is bypassed to the
Internet. To override this behavior, you need to enable 'group-failover' under the cache-group. Refer
to the section '“Configuring group-failover” on page 83 for further details.
Configuring the cache servers
The cache servers return the content to the requesting clients. When configuring content-aware
cache switching, you place the cache servers into logical server groups. CSW policies direct HTTP
requests to one of the cache servers in these logical groups.
A server group can contain one or more cache servers. 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. When configuring content-aware cache
switching, you establish the IP address of each cache server and specify the server group to which
it belongs.
To configure CacheServer1 in Figure 21 on page 79, enter commands such as the following
ServerIronADX(config)#server cache-name CacheServer1 192.168.1.101
ServerIronADX(config-rs-CacheServer1)#port http group-id 1 1
ServerIronADX(config-rs-CacheServer1)#exit
Syntax: port http group-id server-group-id-pairs
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 21. 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