10.1 Consumable Resource Handling
Moab is designed to inherently handle consumable resources. Nodes possess resources, and workload consumes resources. Moab tracks any number of consumable resources on a per node and per job basis. Floating cluster resources can be handled as well; see Managing Shared Cluster Resources. When a job is started on a set of nodes, Moab tracks how much of each available resource must be dedicated to the tasks of the job. This allows Moab to prevent per node over-subscription of any resource, be it CPU, memory, swap, or local disk.
Recent resource managers (such as Loadleveler version 3.x) provide the ability to exercise this capability. These capabilities allow a user to specify per task consumable resources and per node available resources. For example, a job may be submitted requiring 20 tasks with 2 CPUs and 256 MB per task. Thus, Moab would allow a node with 1 GB of memory and 16 processors to run 4 of these tasks because 4 tasks would consume all of the available memory. Consumable resources allow more intelligent allocation of resources allowing better management of shared node resources.
No scheduler level configuration is required to enable this capability as Moab detects the needed information automatically from the underlying resource manager.
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