Using an IP sprayer with Domino® for HTTP and POP3 failover

Instead of using the ICM, you can use an IP sprayer to let HTTP clients access Domino® Web servers in a cluster. The client requests go through the IP sprayer, which distributes the requests to available cluster servers that have replicas of the requested databases. If a cluster server is unavailable, the IP sprayer directs the client request to a different cluster server that contains a replica of the requested database.

Using an IP sprayer gives you some distribution of the workload, but it does not use intelligent failover. In other words, the IP sprayer does not know what the load is on the Domino® servers so it does not redirect requests to the server with the smallest load. In addition, the IP sprayer cannot obtain information from the Cluster Database Directory. Therefore, you must configure the sprayer so that each server it looks on for a particular database contains a replica of that database.

For example, you can configure an IP sprayer to alternate between Web Server 1 and Web Server 2 when directing HTTP client requests. This helps to balance the workload. If either server becomes unavailable, the IP sprayer directs all requests to the server that is still available.

You can also use an IP sprayer for failover with POP3 clients.