Deep health checks
SageMaker HyperPod performs deep health checks on cluster instances during the creation and update of HyperPod clusters. The deep health checks ensure the reliability and stability of the SageMaker HyperPod clusters by thoroughly testing the underlying hardware and infrastructure components before allowing the clusters to be used for training machine learning models. This proactive approach helps identify and mitigate potential issues early in the cluster lifecycle.
List of deep health checks done by SageMaker HyperPod
SageMaker HyperPod runs the following deep health checks.
Instance-level deep health checks
| Category | Utility name | Instance type compatibility | Description |
|---|---|---|---|
| Accelerator | GPU/NVLink count | GPU | Verifies GPU/NVLink counts. |
| Accelerator | DCGM diagnostics |
GPU | Assesses the health and functionality of NVIDIA GPUs by running DCGM (NVIDIA Data Center GPU Manager) diagnostics at level 4, including additional memory tests. |
| Accelerator | Neuron sysfs | Trainium | For Trainium-powered instances, the health of the Neuron devices is
determined by reading counters from Neuron sysfs |
| Accelerator | Neuron hardware check | Trainium | Runs a training workload to produce numbers. it then verifies aiming to test the hardware. |
| Accelerator | NCCOM local test | Trainium | Evaluates the performance of collective communication operations on single Trainium nodes |
| Network | EFA | GPU and Trainium | Runs latency and bandwidth benchmarking on the attached EFA device. |
Cluster-level deep health checks
| Category | Utility name | Instance type compatibility | Description |
|---|---|---|---|
| Accelerator | NCCL test | GPU | Verifies the performance of collective communication operations on multiple NVIDIA GPUs |
| Accelerator | NCCOM cluster test | Trainium | Verifies the performance of collective communication operations on multiple Trainium nodes |
Logs from the deep health checks
The following are example logs from the SageMaker HyperPod deep health checks.
Cluster-level logs
The cluster-level deep health check logs are stored in your CloudWatch log group at
/aws/sagemaker/Clusters/<cluster_name>/<cluster_id>
The log streams are logged at
DeepHealthCheckResults/<log_stream_id>.
As an example shown below, the deep health check output logs show the instance ID that failed the checks with the cause of the failure.
{ "level": "error", "ts": "2024-06-18T21:15:22Z", "msg": "Encountered FaultyInstance. Replace the Instance. Region: us-west-2, InstanceType: p4d.24xlarge. ERROR:Bandwidth has less than threshold: Expected minimum threshold :80,NCCL Test output Bw: 30" }
Instance-level logs
The instance-level deep health check logs are stored at
/var/log/aws/clusterscat/sagemaker-deep-health-check.log on each
node. SSH into the node and open the log file by running the following
command.
cat /var/log/aws/clusterscat/sagemaker-deep-health-check.log
The following is an example output of the hardware stress, NVIDIA DCGM
# Hardware Stress Test output 2024-08-20T21:53:58Z info Executing Hardware stress check with command: stress-ng, and args: [--cpu 32 --vm 2 --hdd 1 --fork 8 --switch 4 --timeout 60 --metrics] 2024-08-20T21:54:58Z info stress-ng success 2024-08-20T21:54:58Z info GpuPci Count check success # DCGM Stress Test 2024-08-20T22:25:02Z info DCGM diagnostic health summary: dcgmCheckLevel: 0 dcgmVersion: 3.3.7 gpuDriverVersion: 535.183.01, gpuDeviceIds: [2237] replacementRequired: false rebootRequired:false # EFA Loopback Test 2024-08-20T22:26:28Z info EFA Loopback check passed for device: rdmap0s29 . Output summary is MaxBw: 58.590000, AvgBw: 32.420000, MaxTypicalLat: 30.870000, MinTypicalLat: 20.080000, AvgLat: 21.630000
The following is an example output of the NCCL connectivity test.
# size count type redop root time algbw busbw #wrong time algbw busbw #wrong # (B) (elements) (us) (GB/s) (GB/s) (us) (GB/s) (GB/s) 8 2 float sum -1 353.9 0.00 0.00 0 304.2 0.00 0.00 0 16 4 float sum -1 352.8 0.00 0.00 0 422.9 0.00 0.00 0 32 8 float sum -1 520.0 0.00 0.00 0 480.3 0.00 0.00 0 64 16 float sum -1 563.0 0.00 0.00 0 416.1 0.00 0.00 0 128 32 float sum -1 245.1 0.00 0.00 0 308.4 0.00 0.00 0 256 64 float sum -1 310.8 0.00 0.00 0 304.9 0.00 0.00 0 512 128 float sum -1 304.9 0.00 0.00 0 300.8 0.00 0.00 0 1024 256 float sum -1 509.3 0.00 0.00 0 495.4 0.00 0.00 0 2048 512 float sum -1 530.3 0.00 0.00 0 420.0 0.00 0.00 0 4096 1024 float sum -1 391.2 0.01 0.01 0 384.5 0.01 0.01 0 8192 2048 float sum -1 328.5 0.02 0.02 0 253.2 0.03 0.03 0 16384 4096 float sum -1 497.6 0.03 0.03 0 490.9 0.03 0.03 0 32768 8192 float sum -1 496.7 0.07 0.07 0 425.0 0.08 0.08 0 65536 16384 float sum -1 448.0 0.15 0.15 0 501.0 0.13 0.13 0 131072 32768 float sum -1 577.4 0.23 0.23 0 593.4 0.22 0.22 0 262144 65536 float sum -1 757.8 0.35 0.35 0 721.6 0.36 0.36 0 524288 131072 float sum -1 1057.1 0.50 0.50 0 1019.1 0.51 0.51 0 1048576 262144 float sum -1 1460.5 0.72 0.72 0 1435.6 0.73 0.73 0 2097152 524288 float sum -1 2450.6 0.86 0.86 0 2583.1 0.81 0.81 0 4194304 1048576 float sum -1 4344.5 0.97 0.97 0 4419.3 0.95 0.95 0 8388608 2097152 float sum -1 8176.5 1.03 1.03 0 8197.8 1.02 1.02 0 16777216 4194304 float sum -1 15312 1.10 1.10 0 15426 1.09 1.09 0 33554432 8388608 float sum -1 30149 1.11 1.11 0 29941 1.12 1.12 0 67108864 16777216 float sum -1 57819 1.16 1.16 0 58635 1.14 1.14 0 134217728 33554432 float sum -1 115699 1.16 1.16 0 115331 1.16 1.16 0 268435456 67108864 float sum -1 227507 1.18 1.18 0 228047 1.18 1.18 0 536870912 134217728 float sum -1 453751 1.18 1.18 0 456595 1.18 1.18 0 1073741824 268435456 float sum -1 911719 1.18 1.18 0 911808 1.18 1.18 0 2147483648 536870912 float sum -1 1804971 1.19 1.19 0 1806895 1.19 1.19 0 2024-08-20T16:22:43.831-07:00 # Out of bounds values : 0 OK 2024-08-20T16:22:43.831-07:00 # Avg bus bandwidth : 0.488398 2024-08-20T23:22:43Z info Nccl test successful. Summary: NcclMaxAlgoBw: 1.190000, NcclAvgAlgoBw: 0.488398, NcclThresholdAlgoBw: 1.180000, NcclOutOfBoundError: OK, NcclOperations: all_reduce_perf, NcclTotalDevices: 2, NcclNodes: 2, NcclClusterMessage:
