A Fire/EMS InfiniBand fabric sees a degraded optical link before host jobs fail. Where should operators spot it first?
Select an answer to reveal the explanation.
Short Explanation
Bad optics usually whisper in the fabric view before they scream in the job logs. Use UFM InfiniBand link status so Fire/EMS ops catch the degraded optical early.
Full Explanation
In a Fire/EMS InfiniBand fabric, optical degradation typically appears in the management plane before GPU jobs abort. UFM InfiniBand link-status monitoring is the correct early detection point because it continuously tracks physical and logical link health—signal integrity, port state transitions, and error counters—across the municipal fabric. Operators watching UFM can isolate a failing transceiver, fiber, or switch port while training or inference workloads are still running, then schedule targeted remediation instead of waiting for a widespread outage that delays emergency analytics.
Relying only on DCGM GPU thermal and memory monitoring fails conceptually: those metrics report compute-node health such as temperature and memory usage and do not identify which InfiniBand optical link is degraded or provide early fabric-level fault detection. Subnet Manager routing table dumps fail because they show active path resolution details rather than live optical health, and they cannot detect bit-error rate rises or flap events in real time. Host syslog CPU utilization graphs fail operationally: they track workload performance trends on hosts, not fabric link health, so they leave operators blind to a degrading optical link until jobs are already affected.
Exam caveat: UFM does not replace host-level debugging; it precedes it. Link-status monitoring is the first fabric-scoped signal, not proof that every application timeout is optical. Correlate UFM link events with topology and affected hosts before swapping hardware.
Operational check: Confirm UFM is subscribed to the Fire/EMS InfiniBand fabric, link-status and optical-health views are enabled, alert thresholds for symbol errors and flaps are defined, and on-call receives those alerts. During the next maintenance window, induce or review a known degraded link event and verify it appears in UFM before any GPU job failure is logged.