The lazy start controller monitors the workload for dynamic clusters
that you explicitly mark for deactivation. This controller triggers the placement
controller to run off cycle and activate an inactive dynamic cluster when
workload is detected. The lazy start controller also informs the placement
controller when it is appropriate to deactivate these clusters.
The lazy start controller maintains the following information for each
dynamic cluster that can be deactivated:
- Deactivation timeout
- Specifies the minimum idle time before the deactivation of a dynamic cluster,
which can be deactivated. Deactivation stops all instances of a dynamic cluster.
The lazy start controller deactivates a cluster only if it perceives a condition
of memory contention on the node that is running an idle application server.
- Time of last activity
- Specifies the time at which the cluster was last active. The lazy start
controller compares the time of last activity to the current time to determine
how long the cluster has been inactive. This value is then compared to the
deactivation timeout value to determine if the dynamic cluster should be deactivated
if another dynamic cluster needs resources.
- State
- Specifies if the dynamic cluster is in Active, Inactive, and Unknown state.
A dynamic cluster state is initially Unknown. If queue activity or active
instances are detected, then the state is changed to Active. If the cluster
is idle for a sufficient time, according to the deactivation timeout property,
the state is switched to Inactive.