Product Documentation

A Typical Load Balancing Scenario

Aug 23, 2013

In a load balancing setup, the NetScaler appliances are logically located between the client and the server farm, and they manage traffic flow to the servers.

The following figure shows the topology of a basic load balancing configuration.

Figure 1. Basic Load Balancing Topology


The virtual server selects the service and assigns it to serve client requests. Consider the scenario in the preceding figure, where the services service-HTTP-1 and service-HTTP-2 are created and bound to the virtual server named virtual server-LB-1. Virtual server-LB-1 forwards the client request to either service-HTTP-1 or service-HTTP-2. The system selects the service for each request by using the Least Connections load balancing method. The following table lists the names and values of the basic entities that must be configured on the system.

Table 1. LB Configuration Parameter Values
Entity Type Required parameters and sample values
Name IP Address Port Protocol
Virtual Server vserver-LB-1 10.102.29.60 80 HTTP
Services service-HTTP-1 10.102.29.5 8083 HTTP
service-HTTP-2 10.102.29.6 80 HTTP
Monitors Default None None None

The following figure shows the load balancing sample values and required parameters that are described in the preceding table.

Figure 2. Load Balancing Entity Model

The following tables list the commands used to configure this load balancing setup by using the command line interface.

Table 2. Initial Configuration Tasks
Task Command
To enable load balancing enable feature lb
To create a service named service-HTTP-1 add service service-HTTP-1 10.102.29.5 HTTP 80
To create a service named service-HTTP-2 add service service-HTTP-2 10.102.29.6 HTTP 80
To create a virtual server named vserver-LB-1 add lb vserver vserver-LB-1 HTTP 10.102.29.60 80
To bind a service named service-HTTP-1 to a virtual server named vserver-LB-1 bind lb vserver vserver-LB-1 service-HTTP-1
To bind a service named service-HTTP-2 to a virtual server named vserver-LB-1 bind lb vserver vserver-LB-1 service-HTTP-2

For more information about the initial configuration tasks, see "Enabling Load Balancing" and "Configuring Services and a Vserver."

Table 3. Verification Tasks
Task Command
To view the properties of a virtual server named vserver-LB-1 show lb vserver vserver-LB-1
To view the statistics of a virtual server named vserver-LB-1 stat lb vserver vserver-LB-1
To view the properties of a service named service-HTTP-1 show service service-HTTP-1
To view the statistics of a service named service-HTTP-1 stat service service-HTTP-1
To view the bindings of a service named service-HTTP-1 show service bindings service-HTTP-1
Table 4. Customization Tasks
Task Command
To configure persistence on a virtual server named vserver-LB-1 set lb vserver vserver-LB-1 -persistenceType SOURCEIP -persistenceMask 255.255.255.255 -timeout 2
To configure COOKIEINSERT persistence on a virtual server named vserver-LB-1 set lb vserver vserver-LB-1 -persistenceType COOKIEINSERT
To configure URLPassive persistence on a virtual server named vserver-LB-1 set lb vserver vserver-LB-1 -persistenceType URLPASSIVE
To configure a virtual server to redirect the client request to a URL on a virtual server named vserver-LB-1 set lb vserver vserver-LB-1 -redirectURL http://www.newdomain.com/mysite/maintenance

To set a backup virtual server on a virtual server named vserver-LB-1 set lb vserver vserver-LB-1 -backupVserver vserver-LB-2

For more information about configuring persistence, see "Choosing and Configuring Persistence Settings." For information about configuring a virtual server to redirect a client request to a URL and setting up a backup virtual server, see "Configuring Features to Protect the Load Balancing Configuration."