Configure dynamic application placement

Dynamic application placement is the process by which the features of the Intelligent Management dynamic operations work together to start and stop application instances to meet the fluctuating demand of work requests of varying service policy definitions. This set of actions is controlled by the application placement controller.

• Before configuring application placement, create an on demand router (ODR) and configure the autonomic request flow manager. For more information about configuration, read about configuring the autonomic request flow manager.

• Create a service policy. For more information, read about defining a service policy.

• Verify that we have the correct administrative role. To change the configuration of the application placement controller, you must have a Configurator or Administrator administrative role. To change runtime settings, you must have an Operator or Administrator administrative role.

Dynamic clusters are the deployment target for the applications. When creating a dynamic cluster, you define a minimum and maximum number of application instances, or cluster members. The application placement controller works to keep these numbers of instances available along with working to meet the demand of the defined service policies. For more information about dynamic clusters, read about creating dynamic clusters.

1. Enable or disable the application placement controller and adjust other settings such as the minimum amount of time between placement changes, the server operation timeout, and so on. For more information about enabling, disabling and adjusting settings, read about monitoring and tuning the application placement controller.

2. Configure and manage multi-cell performance in the environment to avoid overprovisioning resources, such as CPU and memory utilization. For more information, read about configuring multi-cell performance management.

3. enable the elasticity mode to add logic that causes the application placement controller to minimize the number of nodes used, as well as remove nodes that are not needed, while still meeting service policy goals. For more information about the elasticity mode, read about configuring elasticity mode.

Subtopics

• (dist)(zos) Overview of application placement
  Dynamic application placement for Internet InterORB Protocol (IIOP), Java Message Service (JMS), and HTTP request types is achieved through the cooperation of various product components. These components include dynamic clusters, the on demand router (ODR) and associated autonomic managers, and the application placement controller. The fluctuating volume of work requests for applications is dynamically met on the application server side by the application placement feature, which ensures the integrity of the defined business goals.

• (dist)(zos) Dynamic application placement
  Dynamic application placement is based on load distribution, service policy, and available resources. We can run applications at various levels within a Intelligent Management environment, ranging from changing relative weights of applications to expanding the Intelligent Management cell. As changes become more drastic and their impacts become more extreme, applications take more time to run.

• (dist)(zos) APCconfig.jacl script
  Use the APCconfig.jacl script to make persistent changes to the application placement controller configuration.

• (dist)(zos) PlacementControllerProcs.jacl script
  We can use the PlacementControllerProcs.jacl script to modify the application placement runtime configuration.

• (dist)(zos) Configure application placement for cells that share the same nodes
  When two cells share the same workstation, such as the same physical machine, the same blade in a blade center, and so on, overuse of memory can occur. We can configure a custom property so that the application placement controller does not overuse resources on the shared hosts.

• (dist)(zos) wve_encodePassword script
  We can use the wve_encodePassword script to encode a password value that you enter in the console. By encoding the password, we can prevent the password from being shared.

• (dist)(zos) Intelligent Management: application placement custom properties
  Custom properties modify the application placement controller configuration. We can use these settings to tune the application placement controller behavior beyond the settings that are in the console.

• (dist)(zos) Configure multi-cell performance management: Star Topology
  Configure and manage multi-cell performance in the environment to avoid overprovisioning resources, such as CPU and memory utilization. Adding or removing cells to a star topology is completely dynamic. However, the center cell has to be restarted after the CenterCell=true custom property is set.

• (dist)(zos) Configure multi-cell performance management: Peer-Cell Topology
  Configure and manage multi-cell performance in the environment to avoid overprovisioning resources, such as CPU and memory utilization.

• (dist)(zos) Manually disabling communication between multiple cells
  We can complete a set of steps to manually disable the overlay communication between multiple cells.

• (dist)(zos) linkCells|linkCellsZOS script
  When you set up a star topology, we can use the linkCells script to configure the overlay communication between multiple cells. On z/OS systems, use the linkCellsZOS script instead.

• (dist)(zos) unlinkCells|unlinkCellsZOS script
  We can use unlinkCells script to disable the overlay communication between multiple cells. On z/OS systems, use unlinkCellsZOS.

• (dist)(zos) importOverlayConfig.py script
  When setting up a star topology, we can use the importOverlayConfig.py script to configure the overlay communication between multiple cells.

• (dist)(zos) Configure elasticity mode
  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.

• (dist)(zos) Monitor and tune the application placement controller
  The application placement controller is designed to work with the default settings. However, there can be times when fine tuning the application placement controller becomes necessary to ensure the best results.

• (dist)(zos) Intelligent Management: application placement frequently asked questions
  Occasionally, you might encounter application placement behavior that is not expected. This topic describes some commonly asked questions and things to look for when application placement is not working as you expect.

• (dist)(zos) Intelligent Management: application placement controller logs
  We can use the log files to troubleshoot issues with the application placement controller, such as the placement of new instances.

• (dist)(zos)(v8550) Intelligent Management: application placement controller logs
  Use the log files to review the status of the application placement controller.

Related concepts

Overview of application placement

Related information:

Intelligent Management: application placement custom properties

Configure the autonomic request flow manager

Define a service policy

Create dynamic clusters