Server load balancing for applications

Load balancing efficiently distributes network traffic across a group of back end servers. A load balancer is piece of hardware (or virtual hardware) that distributes network and application traffic across different servers. It's used to increase the concurrent user capacity and overall reliability of applications. Enterprise Application Access can balance traffic load across a group of servers, monitor the health of each application server, and apply a variety of load balancing policies. Enterprise Application Access uses these advanced application settings to configure server load balancing:

• Metric. Enterprise Application Access distributes traffic across origin servers by either round-robin or IP hash metrics. For round-robin balancing, traffic is distributed across all available servers. For IP hash balancing, EAA takes a hash from a specified server and serves the session content from there. The default metric is round-robin.

• Enable session stickiness for applications. Session stickiness makes sure that a session uses the same connector when interacting with the application. When this is enabled, Enterprise Application Access uses sticky cookies which stay in place and do not change in order to maintain the same IP address for the session. In this way, the application always sees the same IP address for the session. This feature is needed for state maintenance of some applications.

• Refresh sticky cookies. Enterprise Application Access can refresh a sticky cookie to make sure that the content goes to the same connector (server) to prevent session lag or content loss in a session. Even after the session length has passed, the session does not go to a new connector. This feature is only available when you enable session stickiness.

Add Application IP/FQDN for application servers and configure server load balancing

Configure an application for load balancing using two or more application servers.

1. Log in to the Enterprise Center.

2. In the Enterprise Center navigation menu, select Application Access > Applications > Applications.

3. Select the application to open it.

4. In Settings > Server Settings in the Application server IP/FQDN enter the IP address or FQDN and port number for an application server.

5. Click Add server to add additional servers.

6. In Advanced > Server load balancing select one of the Metric parameters:

   • round-robin (default)
   • IP hash

7. To enable sticky cookies, select Enable Session Stickiness.

8. Choose either to Specify cookie age and enter a cookie age in seconds or Derive the age from the server cookie if you prefer to use the cookie lifetime set by the origin server. If you choose to derive the age from the server, type the server cookie name into the field.

9. Select Refresh sticky cookie.

10. Click Save and Deploy.