Configure elasticity mode

Overview

Configure elasticity mode to allow the application placement controller to minimize the number of used nodes, and to remove nodes that are not needed, while still meeting service policy goals. Additionally, we can configure elasticity mode so that if the controller recognizes that a particular dynamic cluster is not meeting service policies although all possible servers are in use, the controller adds a node.

• For optimal performance, ensure that our dynamic clusters are running in supervised mode or automatic mode.

  It is not recommended to have elasticity mode enabled when dynamic clusters are running in manual mode. However, if the dynamic clusters are running in manual mode with elasticity enabled, consider the following items:

  • The controller does not add nodes to dynamic clusters in manual mode.
  • The controller does not remove nodes from dynamic clusters in manual mode when a server is started on the specific nodes.
  • The controller does remove nodes from dynamic clusters in manual mode when a server is not started on the specific nodes.

• It is not recommended to enable elasticity mode when the following option is set in the administrative console for one or more dynamic clusters:
  If other dynamic clusters need resources, stop all instances of this cluster during periods of inactivity.

  

  If we have elasticity mode enabled and the option set, the application placement controller can remove all of the custom nodes in the cell.

Configure elasticity mode

1. Configure the application placement controller to start on the deployment manager:

   1. In the administrative console, select...
      System administration | Deployment manager | Java and process management | Process definition | Java virtual machine | Custom properties

   2. Enter the name of the custom property as...
      HAManagedItemPreferred_apc

   3. Set the value of the custom property to true.

   4. Click Apply, and save the changes.

   5. Restart the current process in which the application placement controller is running.

   Alternatively, configure the application placement controller to start on the node:

   1. In the administrative console, select...
      System administration | Nodes | node | node_agent_name | Java and process management | Process definition | Java virtual machine | Custom properties

   2. Enter the name of the custom property as...
      HAManagedItemPreferred_apc

   3. Set the value of the custom property to true.

   4. Click Apply, and save the changes.

   5. Restart the current process in which the application placement controller is running.

2. Configure the controllers to start on the deployment managers of the center cell and the point cells when we enable elasticity mode in an environment in which multi-cell performance management is configured by setting the custom properties...
   • HAManagedItemPreferred_apc
   • HAManagedItemPreferred_cellagent

   Configure the application placement controller to start on the deployment manager of the center cell:

   1. In the administrative console, select...
      System administration | Deployment manager | Java and process management | Process definition | Java virtual machine | Custom properties

   2. Enter the name of the custom property as HAManagedItemPreferred_apc.

   3. Set the value of the custom property to true.

   4. Click Apply, and save the changes.

   5. Restart the current process in which the application placement controller is running.

   Configure the cell agent to start on the deployment managers of the point cells:

   1. In the administrative console, select...
      System administration > Deployment manager > Java and process management > Process definition > Java virtual machine > Custom properties

   2. Enter the name of the custom property as HAManagedItemPreferred_cellagent.

   3. Set the value of the custom property to true.

   4. Click Apply, and save the changes.

   5. Restart the current process in which the application placement controller is running.

3. Enable elasticity mode
   Operational policies | Autonomic controllers | Application placement controller

   

   1. Select the check box...
      Enable elasticity operation

   2. Set elasticity to either supervised or automatic mode.

   3. Set the timeout value.

      This value defines the allotted period of time that the application placement controller allows the task to complete. If the task does not complete within the specified amount of time, the application placement controller marks the task as failed. Specify the value in minutes. The default is 10.

      If we change the elasticity operations timeout value in the WAS administrative console or using a wsadmin command, make the same change in the pattern as well. When a new On-Demand Router (ODR) is requested by the Application Placement Controller (APC), the updated elasticity operations timeout value is not overwritten by the timeout value specified in the pattern.

   4. Click Apply, and save the changes.

4. Define the actions of the elasticity operations.

   An elasticity operation defines the runtime behaviors to monitor, and the corrective actions to take when the behaviors are present. Select...

   Operational policies | Autonomic controllers | Application placement controller | Elasticity operation | operation

   1. To add additional actions to the add operation, click Add Action....

      Select the custom action from the list of custom elasticity operation actions. If no custom actions are defined, select...

      Operational policies | Autonomic controllers | Application placement controller | Elasticity custom actions | New

   2. To add additional actions to the remove operation, click Add action...

      Select the custom action from the list of custom elasticity operation actions. If no custom actions are defined, select...

      Operational policies | Autonomic controllers | Application placement controller | Elasticity custom actions | New

Subtopics

• Elasticity mode
  

Configure multi-cell performance management: Star Topology

Create dynamic clusters

Intelligent Management: custom properties