Constraints¶
A Constraint enables you to limit where an execution profile can run workloads to worker nodes with a specified label.
Constraints can be applied to an Execution Profile that limit the list of nodes in the Altair SLC Hub cluster that are eligible to run the given workload.
The Constraints tab enables you to specify operating system constraints and nodel label constraints that will be applied to the execution profile when run.
Operating System Constraint¶
In an Altair SLC Hub cluster containing a mix of Linux and Windows worker nodes, you can define an operating system constraint on an execution profile to ensure that workloads only run on the appropriate node.
You can use the Operating system dropdown list to select the operating system required to run a workload.
Node Label Constraint¶
Worker nodes in the Altair SLC Hub cluster can be given one or more node labels, usually when Altair SLC Hub is first configured. This label can then be used to specify which worker node can execute a workload.
You can use the Node Labels dropdown list to select the labels the worker node should have. Selecting a label in this field will constrain the workload to the identified node. If multiple node labels are specified, a worker node must have all the selected labels for the workload to execute.
Node labels can be combined with other constraints in a profile to provide access to different resources on the same worker node. Node labels can also be used to label nodes for different purposes, for example "Production", "Staging", or "Test". Execution profiles can then be created to ensure that only production jobs are run on the nodes that are labelled with the "Production" label.
If using node labels to identify worker nodes in a cluster to limit where workloads can be run, you must ensure that all available execution profiles provide suitable constraints in addition to using node labels. It is also important to ensure that there are no execution profiles made available that do not constrain based on the node label.