Diagram of listener clustering

This diagram illustrates a three-node listener cluster configuration.

Note: The following summary provides a high-level overview of the components. Details are provided in separate topics.

A cluster consists of multiple listener nodes. Each node (unica_aclsnr) is on a separate physical machine, and each node has a native ODBC connection to the Unica Campaign system database. As with a single-node configuration, each unica_aclsnr process spawns additional back-end processes for logins and flowcharts.

Each node also has a connection to a back-end user database (not shown in diagram).

In a clustered configuration, one node acts as the master listener. The job of the master listener is to perform load balancing by distributing incoming requests to each node. The Unica Campaign web application sends client requests over TCP/IP, and the load balancer component communicates with clustered nodes over TCP/IP. All nodes share a network file system, so they can access shared files. Additionally, each node has its own local tmp folder and its own set of files that are not shared.

Diagram of 3-node listener cluster configuration explained in text