16.4 Maximizing scheduling efficiency
Context
When considering whether to power a node on or off, Moab can take into account the amount of time that it takes to power on or power off the node. With this information, Moab can keep an idle node powered on if it knows that workload in the queue will be ready for the node in less time that it takes to power off/power on the node.
Moab can also wait to shut down nodes after they've been idle for a specific amount of time.
To specify node power on/power off duration
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Modify the NODEPOWERONDURATION and NODEPOWEROFFDURATION attributes of PARCFG with the maximum amount of time it takes for your nodes to power on/power off. Make sure to use the keyword ALL for the resource manager name to avoid cases where Moab won't consider the power on/off duration for a node before making a power action decision.
PARCFG[ALL] NODEPOWERONDURATION=2:00 PARCFG[ALL] NODEPOWEROFFDURATION=2:00
If a node goes idle and has to wait for workload, Moab will not power off the node if the workload will be available within 4 minutes or less.
To shut down on nodes after they've been idle for a specified time
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Modify the NODEIDLEPOWERTHRESHOLD parameter with the duration (in seconds) you want Moab to wait before shutting down an idle node. The default value is 60 seconds. Increasing the number should decrease power on/off thrashing. This should be set higher than NODEPOWERONDURATION and/or NODEPOWEROFFDURATION.
NODEIDLEPOWERTHRESHOLD 300
Moab will wait 5 minutes before shutting down a node that has become idle.
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