{"record":{"id":"f2c7216315dc746e","repo":"vllm-project/vllm","slug":"nixl-eplb-init-failed-name","errorCode":null,"errorMessage":"NIXL EPLB init failed: {name}","messagePattern":"NIXL EPLB init failed: (.+?)","errorType":"exception","errorClass":"RuntimeError","httpStatus":null,"severity":"error","filePath":"vllm/distributed/eplb/eplb_communicator.py","lineNumber":351,"sourceCode":"        \"\"\"\n        self._init_step(\"agents\", self._init_remote_agents)\n        self._init_step(\"send meta\", self._exchange_remote_send_meta)\n        self._remote_state_initialized = True\n\n    def _ensure_remote_state(self) -> None:\n        if not self._remote_state_initialized:\n            self._init_remote_state()\n\n    @property\n    def needs_profile_buffer_reservation(self) -> bool:\n        return False\n\n    @staticmethod\n    def _init_step(name: str, fn: object, *args: object, **kwargs: object) -> None:\n        try:\n            fn(*args, **kwargs)  # type: ignore[operator]\n        except Exception as exc:\n            raise RuntimeError(f\"NIXL EPLB init failed: {name}\") from exc\n\n    def _make_agent_name(self) -> str:\n        \"\"\"Build a deployment-unique nixl agent name.\"\"\"\n        pp_size = get_pp_group().world_size\n        pp_suffix = f\"-pp{get_pp_group().rank_in_group}\" if pp_size > 1 else \"\"\n        uid = uuid.uuid4().hex[:8]\n        return f\"eplb-{self._rank}{pp_suffix}-{uid}\"\n\n    def set_stream(self, cuda_stream: torch.cuda.Stream | None) -> None:\n        pass\n\n    def add_send(\n        self,\n        tensors: list[torch.Tensor],\n        dst_rank: int,\n        expert_id: int,\n    ) -> None:\n        # No-op: NIXL READ is receiver-initiated. The sender's expert","sourceCodeStart":333,"sourceCodeEnd":369,"githubUrl":"https://github.com/vllm-project/vllm/blob/c794754062d49a8fdb63ab3c5215b488b865030c/vllm/distributed/eplb/eplb_communicator.py#L333-L369","documentation":"Error \"NIXL EPLB init failed: {name}\" thrown in vllm-project/vllm.","triggerScenarios":"Raised at vllm/distributed/eplb/eplb_communicator.py:351 when validation fails: NIXL EPLB init failed. Typically triggered by an incompatible or incomplete vLLM configuration, an unsupported platform/backend combination, or a runtime resource/dependency that is missing.","commonSituations":"Commonly encountered at vllm/distributed/eplb/eplb_communicator.py:351 during vLLM startup/config validation or runtime setup when: (1) conflicting CLI flags or config fields are combined, (2) the current platform (CUDA/ROCm/CPU/XPU) or installed optional packages do not support the requested feature, or (3) a required value is absent or out of range. Resolve by correcting the configuration as described in the message, or by selecting a supported alternative.","solutions":["Check NIXL installation and network configuration; the failed init step is named in the error.","Review NIXL logs for the underlying failure."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"c794754062d49a8fdb63ab3c5215b488b865030c","analyzedAt":"2026-08-14T21:17:39.825Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}