Run a WorkloadRun
WorkloadRun lets you run any distributed workload — training, NCCL benchmark, or custom script — without the full certification pipeline.
Basic example
numNodes is the number of nodes per job group, not a total: the orchestrator partitions all eligible nodes into groups of that size. For example, numNodes: 4 on 16 eligible nodes produces four 4-node jobs.
Targeting specific nodes
With bandwidth measurement
With goodput measurement
Gang scheduling
Distributed workloads can deadlock under the default scheduler when only some of their pods fit on the cluster: the placed pods hold GPUs while waiting for peers that never arrive. Set spec.gangScheduler to opt every workload pod into a gang-aware scheduler, such as KAI Scheduler, which holds all pods until the entire gang can be placed at once.
schedulerName is required. queue is optional and defaults to default-queue; when set, it must be a valid Kubernetes label value (at most 63 characters, beginning and ending with an alphanumeric character, containing only alphanumerics, hyphens, underscores, or dots).
When gangScheduler is set, CRE modifies every pod template generated for the workload — for MPI frameworks that includes both the launcher and the worker pods:
- The configured scheduler name is injected as
schedulerNamein each pod spec, so the pods bypass the default scheduler. - The queue is applied as the
kai.scheduler/queuelabel on the pod template metadata, so a gang-aware scheduler can hold all pods in the gang until they can be placed together.
See API Reference: WorkloadRun for validation details.
Platform overrides
The controller detects the platform (from spec.providerID) and GPU
architecture (from the nvidia.com/gpu.product node label) and applies
platform-specific overrides automatically — the same _lib/ fragments the
certification catalog uses. For MPI workloads, override mpiArgs are
prepended to the launcher command ahead of your own
spec.framework.mpi.mpiArgs, so your values still win under OpenMPI’s
duplicate-parameter handling.
Use nvcrectl workloadrun render --platform aws my-workload.yaml to preview
the exact rendered Workflow, including the platform-applied mpirun args.
View results
See API Reference: WorkloadRun for the full spec.