Maui Scheduler

12.3 Node Specific Policies

Specification of node policies is fairly limited within Maui mainly because the demand for such policies is limited. These policies allow a site to specify on a node by node basis what the node will and will not support. Node policies may be applied to specific nodes or applied system wide using the specification 'NODECFG[DEFAULT] ...' Note that these policies were introduced over time so not all policies are supported in all versions.

MAXJOB

This policy constrains the number of total independent jobs a given node may run simultaneously. It can only be specified via the NODECFG parameter.

MAXJOBPERUSER

This policy constrains the number of total independent jobs a given node may run simultaneously associated with any single user. Like MAXJOB, it can only be specified via the NODECFG parameter.

MAXLOAD

MAXLOAD constrains the CPU load the node will support as opposed to the number of jobs. If the node's load exceeds the MAXLOAD limit and the NODELOADPOLICY parameter is set to ADJUSTSTATE , the node will be marked busy. Under Maui 3.0, the max load policy could be applied system wide using the parameter NODEMAXLOAD.

Node policies are used strictly as constraints. If a node is defined as having a single processor or the NODEACCESSPOLICY is set to DEDICATED, and a MAXJOB policy of 3 is specified, Maui will probably not run more than one job per node. A node's configured processors must be specified so that multiple jobs may run and then the MAXJOB policy will be effective. The number of configured processors per node is specified on a resource manager specific basis. PBS, for example, allows this to be adjusted by setting the number of virtual processors, 'np' per node in the PBS 'nodes' file.

Example:

---
# maui.cfg

NODECFG[node024] MAXJOB=4 MAXJOBPERUSER=2
NODECFG[node025] MAXJOB=2
NODECFG[node026] MAXJOBPERUSER=1
NODECFG[DEFAULT] MAXLOAD=2.5
...
---