[https://nvbugs/6812588][fix] Apply the cluster UCX rules in multi-node disagg tests

[reasonsolo]

Description

Main PR: #20189 (same change; only the waiver lines differ).

On GB300, test_e2e.py::test_openai_disagg_multi_nodes_completion[ctx_tp2pp1-gen_tp2pp1] fails at server startup even with #19544 and #20019 in place (DEBUG_LLM_FUNCTION_CLUSTER_TEST/2106, oci-jhb). The ctx and gen workers on both nodes can't create the NIXL transfer agent:

sock.c:502        UCX ERROR bind(fd=60 addr=fdcd:8200:2971:50c8:73:cdff:fe5d:9cb4%0:0) failed: Cannot assign requested address
ucp_worker.c:1492 UCX ERROR uct_iface_open(tcp/rdma_vf_rail0) failed: Input/output error
RuntimeError: Failed to create NIXL backend: UCX (nixl_utils/transferAgent.cpp:892)

Root cause. On GB300, env() sets UCX_TLS=cuda_copy,cuda_ipc,sm,self,tcp (#14460). It also strips any inherited UCX_TLS/UCX_NET_DEVICES (#9726), so UCX's tcp transport opens every NIC. Besides eth0, the oci-jhb GB300 nodes have four rail NICs (rdma_vf_rail0-3). Each has only IPv6 addresses (ULA plus link-local) and is enslaved to a VRF (master vrf_r0). The tcp transport binds a plain socket to the rail's address, the kernel rejects it, and that one failed iface fails the whole UCX worker. #19544 only changed how TRT-LLM selects its own listen address; this bind happens inside UCX while it enumerates interfaces.

PerfSanity already handles this on oci-jhb and oci-aga with a cluster rule in jenkins/scripts/perf/cluster_env.py (#18982): UCX_TCP_AF_PRIO=inet. With that set, UCX 1.22 lists only interfaces that have an IPv4 address (uct_tcp_query_devices), so the rail NICs are never opened. The multi-node disagg tests did not use those rules.

Fix.

• Move the cluster UCX rule table to tests/test_common/cluster_env.py so tests can share it. jenkins/scripts/perf/cluster_env.py stays as a re-export, so the PerfSanity submit scripts are unchanged. Rules are now structured env dicts; get_ucx_tls_cmd() produces the same shell prefix as before for every rule.
• Add apply_ucx_env(environ, cluster_name, gpu_type): when a cluster-specific rule matches, clears UCX_CUDA_IPC_ENABLE_MNNVL/UCX_TLS/UCX_NET_DEVICES and sets the rule's vars. When SLURM_CLUSTER_NAME is unset or only the catch-all rule matches, it leaves the env unchanged, so unlisted clusters keep their previous behavior (UCX_CUDA_IPC_ENABLE_MNNVL is not stripped there). The GPU type comes from nvidia-smi, cached per process.
• _test_disagg_serving_multi_nodes.py and _test_disagg_serving_multi_nodes_service_discovery.py apply it to the env they pass to the servers, with the cluster from SLURM_CLUSTER_NAME (e.g. oci-jhb-slurm-1). Only these multi-node tests use it. Both keep a GB300 UCX_TLS fallback for GB300 clusters with no rule; it is applied first, so a matching cluster rule overrides it.

Scope. Only the two multi-node disagg tests apply the rules, and only on clusters with a matching rule (SLURM_CLUSTER_NAME). UCX's default on these nodes is unchanged: other tests that use UCX tcp on oci-jhb/oci-aga without the rule (e.g. the single-node disagg integration tests' GB300 get_ucx_tls()), or GB300 clusters with similar rail NICs but no rule, are not covered here.

This PR also removes the GB300 waivers in waives.txt for the two test_openai_disagg_multi_nodes_completion variants (ctx_tp1pp2-gen_tp1pp2, ctx_tp2pp1-gen_tp2pp1, nvbugs/6812588) and for test_openai_disagg_multi_nodes_completion_service_discovery[etcd] (nvbugs/6812591). All three pass on GB300 with this change (see below).

Test Coverage

• tests/unittest/scripts/test_cluster_env.py: existing rule tests now load test_common.cluster_env; added tests for apply_ucx_env (rule applied from SLURM_CLUSTER_NAME, no-op on an unlisted cluster and outside Slurm), detect_gpu_type (parse, cache, nvidia-smi failure), GPU product names, and that the perf re-export shares the rule table. The perf shell prefix was compared against the previous module for every rule and GPU: identical.

On oci-jhb GB300 NVL72 (2 nodes), release/1.3 + this PR built for sm_103, outer env UCX_TLS=tcp UCX_NET_DEVICES=eth0 as in QA:

Test	Result
_test_disagg_serving_multi_nodes.py::test_completion[ctx_tp2pp1-gen_tp2pp1]	1 passed on both nodes
_test_disagg_serving_multi_nodes.py::test_completion[ctx_tp1pp2-gen_tp1pp2]	1 passed on both nodes
_test_disagg_serving_multi_nodes_service_discovery.py::test_completion[etcd]	1 passed on both nodes
tests/unittest/scripts/test_cluster_env.py (in the container)	28 passed

These runs were at 8182097. The later review changes (catch-all no-op, GPU-type cache, GB300 fallback order) do not change the server env on oci-jhb, because the oci-jhb rule matches and sets UCX_TLS itself. Logs are on oci-jhb at /lustre/fsw/portfolios/coreai/users/lizhiz/nvbug6812588/log/ (rules_958758.log plus case_rules_{tp2pp1,tp1pp2,sd}_958758_node{0,1}.log; UCX probe in afprio_958715.log).

Both nodes logged UCX env for cluster='oci-jhb-slurm-1' gpu='GB300': ... set {'UCX_TLS': 'cuda_ipc,cuda_copy,sm,self,tcp', 'UCX_TCP_AF_PRIO': 'inet'} and no rail bind errors. service_discovery[http] (not in CI) fails before UCX starts: the disagg server rejects HTTP cluster storage for non-loopback serving.

UCX probe on the same nodes. ucx_info -e creates a UCX worker; UCX_TLS=cuda_copy,cuda_ipc,sm,self,tcp is what the GB300 branch of env() sets:

UCX_TCP_AF_PRIO	tcp devices	worker
default (inet,inet6), baseline without this PR	eth0, lo, rdma_vf_rail0-3	fails: rail0 bind error (the bug)
inet, set by the oci-jhb rule	eth0, lo	OK
inet6	rdma_vf_rail0-3	fails: rail0 bind error

The release/1.3 test without this PR fails with the rail0 bind error, the same as run 2106.

Bug: https://nvbugspro.nvidia.com/bug/6812588

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Walkthrough

The multi-node test identifies the local IPv4 interface used to reach the other host. For sm_103 GPUs on aarch64, it sets UCX_NET_DEVICES to that interface. Two GB300 multi-node completion test skip entries are removed.

Changes

UCX network device selection

Layer / File(s)	Summary
Find and set the route interface tests/unittest/llmapi/apps/_test_disagg_serving_multi_nodes.py	The test maps the local IPv4 address for a host route to a network interface. In the sm_103 and aarch64 environment branch, it sets UCX_NET_DEVICES to that interface. It fails the test if route lookup fails or no interface matches.
Remove completion test waivers tests/integration/test_lists/waives.txt	The waiver list no longer contains skip entries for the ctx_tp1pp2-gen_tp1pp2 and ctx_tp2pp1-gen_tp2pp1 GB300 multi-node completion configurations tracked by NVBUG 6812588.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~8 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to 8c4a3

The GB300 test now selects an IPv4-route interface or fails setup clearly. No actionable merge-blocking risk remains after normal checks.

Pre-merge checks · 4 · 1

Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Title check		The title clearly identifies the fix, the UCX cluster rules, and the affected multi-node disaggregated tests. It matches the primary change and follows the required ticket and type format.
Description check		The description is detailed and covers the failure, root cause, implementation, scope, removed waivers, and test results. It includes the required Description and Test Coverage sections. The PR Checkl…

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Review comments at
@tests/unittest/llmapi/apps/_test_disagg_serving_multi_nodes.py:
- Around line 87-89: Update the interface setup around `_ipv4_nic_to` to fail
with a clear reason when lookup returns `None`, rather than continuing with
`UCX_NET_DEVICES` unset and unrestricted NIC selection.

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[reasonsolo]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #77267 [ run ] triggered by Bot. Commit: 8182097 Link to invocation

[Barry-Delaney]

Re-reviewed 8182097. The shared rule module imports through the PerfSanity compatibility wrapper, and its shell output matches the previous implementation across 100 cluster/GPU inputs. Checked environment clearing/application, unknown-cluster behavior and both multi-node test call sites; three standalone environment cases passed. The additional waiver removal is scoped to the service-discovery test. No blocking code finding. Changed Python parses and diff --check passes; no multi-node GPU run locally.

[tensorrt-cicd]

PR_Github #77267 [ run ] completed with state SUCCESS. Commit: 8182097
/LLM/release-1.3/L0_MergeRequest_PR pipeline #163 completed with status: 'SUCCESS'

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[brnguyen2]

Approving — the comments below are optional touch-ups, not blockers.

Validation covers oci-jhb only, but after this change all six rules in the table apply to these two tests on their clusters (gcp-nrt, oci-hsg, nsc-svg, aws-cmh, aws-dfw pin UCX_NET_DEVICES / UCX_TLS sets tuned for PerfSanity nodes). These tests are only in the QA multinode list, so PR CI will not exercise them. Please confirm which clusters the H100/B200 multi-node QA stages land on and, if any match a rule, run one of them there before merge, or scope apply_ucx_env to the oci rules for now.

Two behaviors differ from the description:

• "Does nothing when the cluster is unknown" holds only when SLURM_CLUSTER_NAME is unset. With it set, the ("*", "*", {}) catch-all matches every cluster, so UCX_CUDA_IPC_ENABLE_MNNVL is now also stripped from the server env on every Slurm run (previously only UCX_TLS/UCX_NET_DEVICES were). Probably intended since PerfSanity does the same, but say so in the description.
• The hardcoded GB300 UCX_TLS block in _test_disagg_serving_multi_nodes.py still runs after apply_ucx_env (inline comment).

Branch order: this lands a module move plus a new helper on release/1.3 first. Please link the main PR; until it merges, jenkins/scripts/perf/cluster_env.py differs between branches and rule edits on main will not cherry-pick cleanly.

Since the waiver removal rests on the manual GB300 run, add the log links for the three passing tests to the PR so the evidence is attached to the change.

Notes on lines outside the diff:

• tests/unittest/llmapi/apps/_test_disagg_serving_multi_nodes.py:84: This runs after apply_ucx_env and unconditionally overwrites UCX_TLS, so on GB300 the cluster table can never change that variable. It works today only because the oci rule sets the same transport set. Move this block above the apply_ucx_env call (so it stays a fallback for GB300 clusters with no rule) and trim the comment accordingly. Note the service-discovery test has no such fallback, so the two files currently disagree on unlisted GB300 clusters.

[mikeiovine]

Stamp on behalf of runtime devs, delegating proper review to @NVIDIA/trt-llm-disagg-devs; please ping me if you think this is not accurate

[reasonsolo]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #77374 [ run ] triggered by Bot. Commit: 700320a Link to invocation

[Barry-Delaney]

Re-reviewed 700320a. Cluster-specific UCX rules now override the GB300 fallback, unlisted clusters preserve their existing mapping, and both multi-node fixtures apply the same fallback ordering. GPU detection is cached and retains its failure fallback. Four actual-module environment cases and the subprocess-cache check passed; changed Python parses and diff --check passes. No blocking code finding. Multi-node GPU execution was not performed locally.

[tensorrt-cicd]

PR_Github #77374 [ run ] completed with state SUCCESS. Commit: 700320a
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