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Basic Web Site and e-Commerce Configuraton

Basic web site and e-commerce configuration

The most common application of the BIG-IP Controller is to distribute traffic across an array of web servers that host standard web traffic, including e-commerce traffic.

The following sections provide you with a basic configuration example that can help you plan your installation. These examples can also help you understand how you can use some of the most popular BIG-IP Controller features to resolve specific issues or to enhance network performance in general.

A basic web site and e-commerce configuration

First, we start with a basic configuration where a BIG-IP Controller load balances two sites: www.MySite.com and store.MySite.com. The www.MySite.com site provides standard web content, and the store.MySite.com site is the e-commerce site that sells items to www.MySite.com customers. In this scenario, the BIG-IP Controller provides simple load balancing for both sites.

Setting up the topology

To set up load balancing for these sites, you need to create two pools that are referenced by two virtual servers, one for each site. Even though the sites are related and they may even share the same IP address, each requires its own virtual server because it uses a different port to support its particular protocol: port 80 for the HTTP traffic going to www.MySite.com, and port 443 for the SSL traffic going to store.MySite.com.

Figure 2.1 shows the topology for the sample configuration. Each site uses two of the three web servers to host its content. Both sites happen to share Server 2.

Note: Note that in this example, as in all examples in this guide, we use only non-routable IP addresses. In a real topology, the virtual server IP addresses would have to be routable on the Internet.

Figure 2.1 A basic configuration

The virtual servers that you define always include three basic elements:

• Virtual IP address
  This is the IP address that is registered with DNS and associated with your site's domain name. In our example, both www.MySite.com and store.MySite.com use the same IP address: 192.168.200.10. Both domain names would presumably have to be registered with DNS to resolve to that IP address.
• Port
  The port that hosts the specific service supported by your site. In our example, we have two different sites that support two different ports: port 80 and port 443.
• Pools of servers that host your site
  Pools contain the list of physical servers that actually host your site connections. For a given pool of servers, you list each IP address and port number pair, referred to as a member. Even though our example includes only three physical servers, it actually has four members:
  • Virtual Server 1 references the http_pool that contains two members: 192.168.100.1:80 and 192.168.100.2:80.
  • Virtual Server 2 references the ssl_pool that contains two members: 192.168.100.2:443 and 192.168.100.3:443.

The BIG-IP Controller distributes connections among the three servers according to a user-specified load balancing mode. The most common mode is Round Robin, which simply distributes each new connection to the next server in line, eventually distributing the connections equally among all the servers.

Using additional features

In this type of configuration, you might want to take advantage of the following BIG-IP Controller features:

• Extended Content Verification
  Verifies that the web servers are not only up and running, but also able to send valid content to clients. For example, you could use Extended Content Verification to make sure that www.MySite.com returns its home page rather than an HTTP 404 error.
• Persistence
  Allows returning e-commerce customers to bypass load balancing and connect to the back-end server to which they originally connected that may contain user-specific information. In our example, store.MySite.com provides the ability for users to fill a shopping cart, disconnect from the site, and then return up to 24 hours later to purchase the items. When the user returns to purchase the items, the user may need to go to the same back-end server, depending on how the e-commerce site is set up.
• Network Address Translation
  Allows you to make direct administrative connections to the web servers through the BIG-IP Controller. If your administrative workstation is on the network connected to the BIG-IP Controller's external interface, and administrative workstations frequently are, this feature is essential.
• Secure Network Address Translation (SNAT)
  Allows you to map internally routable IP addresses to an externally routable IP address. SNATs do not allow incoming connections.