v1.0

config/kv_transfer.py

@@ -0,0 +1,114 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import hashlib
+import uuid
+from dataclasses import field
+from typing import Any, Literal, get_args
+
+from pydantic.dataclasses import dataclass
+
+from vllm.config.utils import config
+
+KVProducer = Literal["kv_producer", "kv_both"]
+KVConsumer = Literal["kv_consumer", "kv_both"]
+KVRole = Literal[KVProducer, KVConsumer]
+
+
+@config
+@dataclass
+class KVTransferConfig:
+    """Configuration for distributed KV cache transfer."""
+
+    kv_connector: str | None = None
+    """The KV connector for vLLM to transmit KV caches between vLLM instances.
+    """
+
+    engine_id: str | None = None
+    """The engine id for KV transfers."""
+
+    kv_buffer_device: str = "cuda"
+    """The device used by kv connector to buffer the KV cache. Choices are 
+    'cuda' and 'cpu'."""
+
+    kv_buffer_size: float = 1e9
+    """The buffer size for TorchDistributedConnector. Measured in number of
+    bytes. Recommended value: 1e9 (about 1GB)."""
+
+    kv_role: KVRole | None = None
+    """Whether this vLLM instance produces, consumes KV cache, or both. Choices
+    are 'kv_producer', 'kv_consumer', and 'kv_both'."""
+
+    kv_rank: int | None = None
+    """The rank of this vLLM instance in the KV cache transfer. Typical value:
+    0 for prefill instance, 1 for decode instance.
+    Currently only 1P1D is supported."""
+
+    kv_parallel_size: int = 1
+    """The number of parallel instances for KV cache transfer. For
+    P2pNcclConnector, this should be 2."""
+
+    kv_ip: str = "127.0.0.1"
+    """The KV connector ip, used to build distributed connection."""
+
+    kv_port: int = 14579
+    """The KV connector port, used to build distributed connection."""
+
+    kv_connector_extra_config: dict[str, Any] = field(default_factory=dict)
+    """any extra config that the connector may need."""
+
+    kv_connector_module_path: str | None = None
+    """The Python module path to dynamically load the KV connector from.
+    Only supported in V1."""
+
+    enable_permute_local_kv: bool = False
+    """Experiment feature flag to enable HND to NHD KV Transfer"""
+
+    def compute_hash(self) -> str:
+        """
+        WARNING: Whenever a new field is added to this config,
+        ensure that it is included in the factors list if
+        it affects the computation graph.
+
+        Provide a hash that uniquely identifies all the configs
+        that affect the structure of the computation
+        graph from input ids/embeddings to the final hidden states,
+        excluding anything before input ids/embeddings and after
+        the final hidden states.
+        """
+        # no factors to consider.
+        # this config will not affect the computation graph.
+        factors: list[Any] = []
+        hash_str = hashlib.md5(str(factors).encode(), usedforsecurity=False).hexdigest()
+        return hash_str
+
+    def __post_init__(self) -> None:
+        if self.engine_id is None:
+            self.engine_id = str(uuid.uuid4())
+
+        if self.kv_role is not None and self.kv_role not in get_args(KVRole):
+            raise ValueError(
+                f"Unsupported kv_role: {self.kv_role}. "
+                f"Supported roles are {get_args(KVRole)}"
+            )
+
+        if self.kv_connector is not None and self.kv_role is None:
+            raise ValueError(
+                "Please specify kv_role when kv_connector "
+                f"is set, supported roles are {get_args(KVRole)}"
+            )
+
+    @property
+    def is_kv_transfer_instance(self) -> bool:
+        return self.kv_connector is not None and self.kv_role in get_args(KVRole)
+
+    @property
+    def is_kv_producer(self) -> bool:
+        return self.kv_connector is not None and self.kv_role in get_args(KVProducer)
+
+    @property
+    def is_kv_consumer(self) -> bool:
+        return self.kv_connector is not None and self.kv_role in get_args(KVConsumer)
+
+    def get_from_extra_config(self, key, default) -> Any:
+        return self.kv_connector_extra_config.get(key, default)