Configuring and Managing Load Balancing

You can configure the load balancing service.

Manage a load-balanced group by managing each node. To be certain which appliance you are connecting to, you should connect directly to the real IP address of each node, not the virtual IP address.

To configure load balancing, select Services > Load Balancing. To configure the load balancing service, you need to know the primary IP address (from the eth0 interface) of all participating appliances, as well as an additional, unused IP for the virtual IP address. For each node, select the Role (one primary, all others are secondary), enter the same Virtual IP address, select a Heartbeat Interval, and enter the Appliance IP address for each of the other nodes.

When you are configuring the primary node, enter the IP addresses for all other nodes in the multi-line text box and separate those IP addresses by commas or new lines. When you are configuring a secondary node, an extra line appears for entering the IP address of the primary node with a Fetch config button that obtains the address and fills it in for you. The IP addresses for any other secondary nodes still go in the multi-line text box.

To avoid unnecessary switching of the current director node appliance, you should start the load balancing service on the primary first, and then start it on the secondaries. Likewise, if you are shutting down a load-balanced group, reverse the order: stop load balancing on the secondaries first, and then stop it on the primary.

Whenever a node becomes active, an email notification is sent to the address specified on the Configuring Mail window (System Menu > Mail).

While the load balancing service is running, the control panel header has an LB indicator to show the current status. If this indicator is not green, select it to obtain more information on the problem. You can also view the status information by selecting Status on the Configuration window. To see a log of the system messages about load balancing, select View Logs.

You can use other services, such as SFTP and SSL, with the group's virtual IP address. You must first create matching configurations on all appliances in the group. NextGen Healthcare recommends that you document all changes made to the primary so you can easily make the same changes on the secondaries. NextGen Healthcare recommends performing a test failover of the director role to ensure everything works on each secondary exactly as it does on the primary.