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Fixing NCCL Test For A4X : Updating NCCL network interfaces and enroot paths#5504

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LAVEEN merged 3 commits into
GoogleCloudPlatform:developfrom
LAVEEN:a4xnccltestfix
Apr 16, 2026
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Fixing NCCL Test For A4X : Updating NCCL network interfaces and enroot paths#5504
LAVEEN merged 3 commits into
GoogleCloudPlatform:developfrom
LAVEEN:a4xnccltestfix

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@LAVEEN LAVEEN commented Apr 15, 2026

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This PR fixes issues with NCCL tests on a4x-highgpu-4g clusters by correcting the network interface configuration and fixing the enroot issue.

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@LAVEEN LAVEEN requested review from a team and samskillman as code owners April 15, 2026 12:03
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Summary of Changes

Hello, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses connectivity and environment configuration issues for NCCL tests on a4x-highgpu-4g clusters. By updating the network interface definitions and standardizing the Enroot runtime and cache paths, the changes ensure more reliable execution of GPU-accelerated workloads.

Highlights

  • NCCL Network Configuration: Updated network interface variables (OMPI_MCA_btl_tcp_if_include and NCCL_SOCKET_IFNAME) to use enp0s3 and enp192s2 for improved connectivity.
  • Enroot Path Optimization: Refactored Enroot configuration paths to remove user-specific UID segments and added explicit directory creation and permission management for /mnt/localssd.
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@LAVEEN LAVEEN added the release-bugfix Added to release notes under the "Bug fixes" heading. label Apr 15, 2026
@LAVEEN LAVEEN changed the title Fixing NCCL Test For A4X : Update NCCL network interfaces and enroot paths Fixing NCCL Test For A4X : Updating NCCL network interfaces and enroot paths Apr 15, 2026
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Code Review

This pull request updates the Enroot configuration and network interface settings for the a4x-highgpu-4g blueprint. Key changes include hardcoding Enroot paths to /mnt/localssd and updating NCCL/MPI network interfaces. Feedback focuses on maintaining multi-user support by re-incorporating the ${UID} variable in Enroot paths, using variables instead of hardcoded mount points for better maintainability, and removing a redundant shell script that duplicates functionality already provided by the local_ssd_filesystem setting.

Comment thread examples/machine-learning/a4x-highgpu-4g/a4xhigh-slurm-blueprint.yaml Outdated
Comment thread examples/machine-learning/a4x-highgpu-4g/a4xhigh-slurm-blueprint.yaml Outdated
Comment thread examples/machine-learning/a4x-highgpu-4g/a4xhigh-slurm-blueprint.yaml
Comment thread examples/machine-learning/a4x-highgpu-4g/a4xhigh-slurm-blueprint.yaml Outdated
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LAVEEN commented Apr 15, 2026

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@LAVEEN LAVEEN merged commit 84dd0a3 into GoogleCloudPlatform:develop Apr 16, 2026
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@kvenkatachala333 kvenkatachala333 kvenkatachala333 approved these changes

@samskillman samskillman Awaiting requested review from samskillman

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