Programming Guides › Programming Guide for Java › Agent API › Server Clusters › Cluster Configuration

Cluster Configuration

You can configure a cluster through the Agent API or through a host configuration object using the Policy Server User Interface. If you configure a cluster through the Agent API, be sure that the configuration does not conflict with any cluster configuration information that may be defined in the host configuration object.

You configure the individual servers or clusters of servers that the agent is associated with through the InitDef and ServerDef classes.

Cluster failover occurs according to the following configuration settings:

• Failover threshold. The minimum percentage of servers within a cluster that must be available for Policy Server requests. If the number of available servers falls below the threshold, failover to the next cluster occurs.

  The failover threshold percentage applies to all clusters associated with the agent.

  To determine the number of servers that the percentage represents in any given cluster, multiply the threshold percentage by the number of servers in the cluster, rounding to the nearest integer. For example, with a 60-percent failover threshold for a cluster of five servers, failover to the next cluster occurs when the number of available servers in the currently active cluster falls below 3.

  Set through: InitDef constructor that contains the failOverThreshold parameter.

• Sequence of cluster failover. Each cluster is assigned a sequence number. When cluster failover occurs, SiteMinder sends subsequent Policy Server requests to the next cluster in the cluster sequence.

  Set through: ServerDef.clusterSeq().