To support a pool of Lotus Notes Traveler servers, a single connection URL for the end user devices is required. This can be accomplished by employing an IP sprayer or load balancer, allowing a device to connect to one URL and have the request routed to any of the Lotus Notes Traveler servers in the pool.
The minimal requirements for an IP sprayer or load balancer in a Lotus Notes Traveler implementation include:
- Provides a single URL and supports the proxy of device requests to two or more Lotus Notes Traveler servers.
- Round robin load balancing to spread the load evenly across the Lotus Domino® HTTP tasks as desired. Lotus Notes Traveler provides its own load balancing (within the HA pool) based on server load characteristics after it has received the requests from the Lotus Domino HTTP task.
- The ability to detect when a Lotus Notes Traveler server is no longer responding (to allow for failover).
- Session affinity for a device session is not required but is recommended for efficiency. A short timeout of less than 2 hours is recommended.
When configuring the HA pool, you need to set the Lotus Notes Traveler external URL to point the devices to the URL of the IP sprayer/load balancer through the Traveler tab of the Lotus Notes Traveler server document. All Lotus Notes Traveler servers within the same HA pool must use the same URL value.
When considering the function of load balancing, it is important to keep in mind that the Lotus Notes Traveler servers will be providing their own load balancing, independent of what the front end server does. After the front end server passes a request to a specific Lotus Notes Traveler server, that server will then determine which of the pool of servers should handle the request and forward it as appropriate. For further information on this process, see Load balancing considerations