Setting Up a Group of Web Servers

You can configure a proxy service to service a “virtual” group of web servers, which adds load balancing and redundancy. Each web server in the group must contain the same material. When you create the proxy service, you set up the first server by specifying the URLs you want users to access and the rights the users need for each URL. When you add additional web servers to the proxy service, these servers automatically inherit everything you have configured for the first web server.

Figure 2-19 Adding Redundant Web Servers

For this configuration, you use a single reverse proxy and proxy service. To add multiple web servers to a host:

  1. Click Devices > Access Gateways > Edit > [Name of Reverse Proxy] > [Name of Proxy Service] > Web Servers.

  2. In the Web Server List section, click New.

  3. Specify the IP address or the fully qualified DNS name of another web server for the “virtual” group, then click OK.

  4. Repeat Step2 and Step3 to add additional web servers to the group.

  5. Click OK.

  6. To apply the changes, click the Access Gateways link, then click Update > OK.

Access Gateway uses the round robin algorithm by default. You can configure it to use the simple failover algorithm.

Simple failover sends all the traffic to the first web server as long as it is available. Traffic is sent to another web server in the list only when the first web server is no longer available. To configure this option, see Configuring TCP Connect Options for Web Servers.

Connection persistence is enabled by default. This allows Access Gateway to send multiple HTTP requests to the web server to be serviced before the connection is closed. To configure this option, see Configuring TCP Connect Options for Web Servers.

Session stickiness option is used if multiple web Servers are configured for a service. Selecting this option makes the proxy server to use the same web server for all fills during a session. This option is enabled by default. For more information about persistent connections, see Configuring Connection and Session Persistence.