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.