Dynamic application placement is the process by which the
features of the dynamic operations of WebSphere Virtual Enterprise 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 you begin
- Before configuring application placement, create an on demand
router and configure the autonomic request flow manager. See Configuring the autonomic request flow manager
.
- Create a service policy. See Defining a service policy
.
- Verify that you have the correct administrative role. If you want
to change the configuration of the application placement controller,
you must have a Configurator or Administrator administrative role.
If you want to change runtime settings, you must have an Operator
or Administrator administrative role.
Procedure
- Creating dynamic clusters
Dynamic
clusters are the deployment target for your applications. When you
create 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 your defined service policies.
- Monitoring and tuning the application placement controller
You
can 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.
- Configuring application placement for cells that share the
same nodes
If
you have multiple cells that use the same set of nodes, you must configure
the application placement controller on each cell so that the cells
can communicate with each other about their memory use. This configuration
prevents overuse of memory on the nodes.