Step 5: Configure the dynamic cluster properties

Specifies the minimum number of running instances for the dynamic cluster. If a minimum value is excessive, performance degradation might occur.

• If you want to stop instances when no activity exists, click Stop all instances during periods of inactivity. If you select this option, enter the Time to wait before stopping instances value in minutes.
  Restriction: If you are routing Session Initiation Protocol (SIP) traffic to the dynamic cluster, do not use the If other dynamic clusters need resources, stop all instances of this cluster during periods of inactivity option. Use one of the options that keep at least one cluster member active at all times.
• If you want one cluster instance started at all times, click Keep one instance started at all times. This option is the default.
• If you want more than one cluster instance started at all times, click Keep multiple instances started at all times. If you select this option, enter the Number of instances that you want started at all times.

Specifies the maximum number of cluster instances that can start.

• If you want to limit the number of cluster instances, click Limit the number of instances that can start, and enter the maximum Number of instances.
• If you do not want to limit the number of cluster instances, click Do not limit the number of instances that can start.

Specifies if more than one instance can start on a single node. By configuring vertical stacking, the application placement controller can start more than one instance of the dynamic cluster on the node when a large workload exists.

Use vertical stacking to improve bottleneck conditions between applications. Select Allow more than one instance to start on the same node, and type the Number of instances value. The number of instances is the number of application servers for a cluster that are needed to use all the power of a node. Also, the number you choose for vertical stacking is the number of servers that are automatically created.

If you use target nodes for vertical stacking that are at an older product version than the deployment manager version, adding new members on the same node is disabled. Vertical stacking is available only on application servers, WebSphere® Application Server Community Edition servers, and PHP servers that have cluster members that are automatically defined by rules.

Specifies if you want the dynamic cluster to run on the same nodes as other instances of dynamic clusters, or if you want the dynamic cluster to be the only dynamic cluster that is running on a node. This option is available if you choose to automatically define your cluster members with rules. If you manually define your cluster members, you do not have the option to enable dynamic cluster isolation.

• Select No isolation requirements if cluster instances in this dynamic cluster can run on the same node as other instances from different dynamic clusters. This option is the default.
• Select Strict isolation if cluster instances in this dynamic cluster can run only with other instances of the same dynamic cluster on the same node.
• Select Associate with an isolation group if the cluster instance can run with any other instance of a dynamic cluster that is in the same shared group on the same node. Specify an Isolation group name value. To create a new isolation group for this dynamic cluster, type a unique name. To select from a list of the existing isolation groups, click Browse. A topology of the current isolation groups is displayed. Click an isolation group name to select the group.