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Basic load balancing configuration

Basic load balancing configuration

Consider a company that has a basic social community website where users can register for an account that requires no sensitive information. The user can then log in and post pictures of their pets. The company has three web/application servers, and one database server to back them up. The domain and DNS are hosted with IBM Cloud, and because they have a small environment, the NetScaler and web/app servers are all in the same VLAN. This arrangement simplifies things, because no further configuration is needed for the NetScaler to set up a basic load balancing policy.

The following procedure is an oversimplified explanation of the traffic flow in this instance:

  1. A user enters the URL into their browser.
  2. The URL's DNS record points to one of the public VIPs on the NetScaler.
  3. The NetScaler receives the traffic on that VIP, and makes note of the traffic's protocol being used (HTTP port 80 traffic).
  4. The NetScaler then passes that traffic to one of the servers in the server pool, based on the balancing method defined (round robin, persistence IP, and so on).
  5. The server then accepts the traffic and the user connects and logs in.

To accomplish this, you must configure the NetScaler to handle this traffic. Because the VIP, the DNS server's IP, and the SNIP are already configured, this simplifies the configuration.

Creating servers

In the NetScaler GUI, on the Configuration screen, expand Traffic Management on the left side. Expand the subsection titled Load Balancing. Then tell the NetScaler what target servers to include in the load balancing policy, by following this procedure:

  1. In Load Balancing, click Servers.
  2. Click Add.
  3. Enter the name of the server (for example, Web1).
  4. Enter the IP address of the server.
  5. Leave the Traffic Domain field blank, because you are only concerned with using the default traffic domain in this scenario.
  6. Enter any comments that you want about this server.
  7. Click Create.

Repeat this procedure for all servers in the pool.

To keep servers easily identifiable, use a similar naming convention for servers within the same pool (for example, Web1, Web2, Web3, and so on).

Creating services

Next, create your services. You are creating a service for each server that you just entered. The service is what configures the connection between the NetScaler and the servers in the pool. Each service has a name and specifies an IP address, a port, and the type of data that is served.

  1. Click Traffic Management > Load Balancing > Services.
  2. Click Add.
  3. Create a service for each server that you created earlier, by using the same information.

Next, create a virtual server. The virtual server is a virtual connection between the VIP used for the load-balanced servers and services that you created earlier.

  1. Click Traffic Management > Load Balancing > Virtual Servers.
  2. Click Add.
  3. Name the virtual server.
  4. Designate the protocol that you are balancing (HTTP).
  5. Leave the IP address type as the default (IP address). The IP address field is where you enter the VIP that you are using as the entry point for all of your users.
  6. Designate the port. The default is port 80.
  7. Click OK.

Binding services

Now, bind the services that you created to your virtual server.

  1. On the Virtual Servers screen, click the No Load Balancing Virtual Server Service Binding link.
  2. Bind each of the previously created services to the virtual server.
  3. Click Done.
  4. Click the Refresh button. The State and Effective State show as green.

You have created a load balancing pool and policy for your website.

To learn more about the configuration of the Citrix Netscaler VPX device, see the Citrix documentation page. For further assistance, contact the IBM Cloud Support and sales.