Technical data

ServerIron ADX Advanced Server Load Balancing Guide 101
53-1002435-03
Sample configurations
2
You can override this behavior by enabling the FastCache feature. This feature configures the
ServerIron ADX to continue redirecting client requests to a cache server even though the ServerIron
ADX does not see responses from the cache server. You enable the feature individually for real
servers.
NOTE
Even when use the FastCache feature, the ServerIron ADX still performs a Layer 3 health check by
regularly pinging the cache server. In addition, you can continue to use HTTP health checking.
FIGURE 23 FastCache feature used for asymmetric topology
Here are the commands for configuring the ServerIron ADX for the topology shown in Figure 23. The
line that enables the FastCache feature is shown in bold.
NOTE
This example shows commands that are valid on the ServerIron ADX device only when it is running
the Layer 3 router image.
ServerIronADX(config)# server cache-name cacheserver3 209.157.22.205
ServerIronADX(config-rs-cacheserver3)# asymmetric
ServerIronADX(config-rs-cacheserver3)# exit
Internet
www.stockquotes.com
1.0.0.2
www.oldnews.com
1.0.0.1
www.livenews.com
1.0.0.3
Web Servers
Border Access
Router (BAR)
e18 (output port)
e17
Remote Access
Server (RAS)
Web Queries
208.95.6.3
208.95.7.3
208.95.8.3
Cache server3
209.157.22.205
Cache server4
209.157.22.215
Cache server5
209.157.22.225
The ServerIron uses cache
responses from cache server 4
and cache server 5 for health
checking.
However, cache server 3
responds directly to the
RAS. Therefore, the
direct cache-server return
feature is used to disable
health checking based on
cache responses from cache
server 3.
SI
Cache interface 209.157.22.140.
A default route on this
interface directly to the CAR
bypasses the ServerIron.