Node Attributes

Introduction to node attributes.

Users can control the selection of the compute nodes on which to run their applications and can select nodes on the basis of desired characteristics (node attributes). This allows a placement scheduler to schedule jobs based on the node attributes.

A user invokes the cnselect command to specify node-selection criteria. The cnselect script uses these selection criteria to query the table of node attributes in the SDB and returns a node list to the user based on the results of the query. When launching the application, the user includes the node list using the aprun -L node_list option as described on the aprun(1) man page. The ALPS placement scheduler allocates nodes based on this list.

To meet specific user needs, the administrator can modify the cnselect script. For additional information about the cnselect script, see the cnselect(1) man page.