Question 630
During a shared-cluster operating review at a university HPC center, engineers report the following issue: Operators scale a cluster but job placement yields worse collective performance than before. The affected work supports research training and scheduled compute allocations; fair resource access and repeatable cluster operations matter. Select TWO: the most appropriate action and the strongest verification of that action. (Select TWO.)
Explanation
Correct Answers
Correct corrective action. Place tightly coupled distributed training processes with awareness of accelerator counts, network topology and collective communication demands, and validate gang-scheduling needs. This fits the specific reported issue: Operators scale a cluster but job placement yields worse collective performance than before. The corresponding failure being reduced is: Individually placed workers can deadlock or underperform when all required peers or usable network links are not allocated together.
Correct independent evidence. A multi-node training allocation starts with its required worker set and achieves expected synchronized-step performance without stranded partial jobs. This verifies the corrective approach for the affected research training and scheduled compute allocations instead of treating an architecture diagram alone as success.
Incorrect Answers
Not the most direct the action-and-evidence pair for these facts. Use a workload scheduler such as Slurm with explicit job GPU resource requests, queue policies and fair-share controls for shared training clusters. This choice concerns slurm batch queues fair-share and reservations and may be valid in another design. But this case reports 'Operators scale a cluster but job placement yields worse collective performance than before', which calls for reasoning about distributed job placement and topology-aware orchestration. The targeted response is: Place tightly coupled distributed training processes with awareness of accelerator counts, network topology and collective communication demands, and validate gang-scheduling needs.
Not the most direct the action-and-evidence pair for these facts. Use a secured baseboard management controller and out-of-band path to inspect system sensors, power and remote console status independently of the host operating system. This choice concerns bmc and out-of-band server health administration and may be valid in another design. But this case reports 'Operators scale a cluster but job placement yields worse collective performance than before', which calls for reasoning about distributed job placement and topology-aware orchestration. The targeted response is: Place tightly coupled distributed training processes with awareness of accelerator counts, network topology and collective communication demands, and validate gang-scheduling needs.
Not the most direct the action-and-evidence pair for these facts. A sampled node's actual firmware, GPU, driver and fabric settings match the approved inventory or show a tracked exception. This choice concerns cluster inventory firmware and configuration baseline and may be valid in another design. But this case reports 'Operators scale a cluster but job placement yields worse collective performance than before', which calls for reasoning about distributed job placement and topology-aware orchestration. The targeted response is: Place tightly coupled distributed training processes with awareness of accelerator counts, network topology and collective communication demands, and validate gang-scheduling needs.