vllm-project/vllm · error · ValueError

Unknown event publisher '{kind}'

Error message

Unknown event publisher '{kind}'

What it means

Error "Unknown event publisher '{kind}'" thrown in vllm-project/vllm.

Source

Thrown at vllm/distributed/kv_events.py:559

    def create(
        cls, config: KVEventsConfig | None, data_parallel_rank: int = 0
    ) -> EventPublisher:
        """Create publisher from a config mapping."""
        if (
            config is None
            or not config.enable_kv_cache_events
            or config.publisher == "null"
        ):
            return NullEventPublisher()

        config_dict = asdict(config)

        kind = config_dict.pop("publisher")
        config_dict.pop("enable_kv_cache_events")
        try:
            constructor = cls._registry[kind]
        except KeyError as exc:
            raise ValueError(f"Unknown event publisher '{kind}'") from exc
        return constructor(data_parallel_rank=data_parallel_rank, **config_dict)

View on GitHub (pinned to c794754062)

Solutions

1. Use a known event publisher kind (e.g. 'zmq' or 'null').

When it happens

Trigger: Raised at vllm/distributed/kv_events.py:559 when validation fails: Unknown event publisher. Typically triggered by an incompatible or incomplete vLLM configuration, an unsupported platform/backend combination, or a runtime resource/dependency that is missing.

Common situations: Commonly encountered at vllm/distributed/kv_events.py:559 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.

AI-assisted analysis of vllm-project/vllm@c794754062 (2026-08-14). Data as JSON: /api/errors/085357fa51ffb957. Report an issue: GitHub.