11.0 General Node Administration
- Node Location
- Node Attributes
- Node Specific Policies
- Managing Shared Cluster Resources (Floating Resources)
- Managing Node State
- Managing Consumable Generic Resources
- Enabling Generic Metrics
- Enabling Generic Events
11.0-A Overview
Moab has a very flexible and generalized definition of a node. This flexible definition, together with the fact that Moab must inter-operate with many resource managers of varying capacities, requires that Moab must possess a complete set of mechanisms for managing nodes that in some cases may be redundant with resource manager facilities.
Resource Manager Specified 'Opaque' Attributes
Many resource managers support the concept of opaque node attributes, allowing a site to assign arbitrary strings to a node. These strings are opaque in the sense that the resource manager passes them along to the scheduler without assigning any meaning to them. Nodes possessing these opaque attributes can then be requested by various jobs. Using certain Moab parameters, sites can assign a meaning within Moab to these opaque node attributes and extract specific node information. For example, setting the parameter FEATUREPROCSPEEDHEADER xps causes a node with the opaque string xps950 to be assigned a processor speed of 950 MHz within Moab.
Scheduler Specified Default Node Attributes
Some default node attributes can be assigned on a rack or partition basis. In addition, many node attributes can be specified globally by configuring the DEFAULT node template using the NODECFG parameter (i.e., NODECFG[DEFAULT] PROCSPEED=3200). Unless explicitly specified otherwise, nodes inherit node attributes from the associated rack or partition or from the default node template. See the Partition Overview for more information.
Scheduler Specified Node Attributes
The NODECFG parameter also allows direct per-node specification of virtually all node attributes supported via other mechanisms and also provides a number of additional attributes not found elsewhere. For example, a site administrator may want to specify something like the following:
NODECFG[node031] MAXJOB=2 PROCSPEED=600 PARTITION=small
These approaches may be mixed and matched according to the site's local needs. Precedence for the approaches generally follows the order listed earlier in cases where conflicting node configuration information is specified through one or more mechanisms.