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| 1 | +# Copyright (c) Meta Platforms, Inc. and affiliates. |
| 2 | +# |
| 3 | +# This source code is licensed under the MIT license found in the |
| 4 | +# LICENSE file in the root directory of this source tree. |
| 5 | + |
| 6 | +"""Helper classes for Ray-based weight synchronization tests. |
| 7 | +
|
| 8 | +This module contains Ray actor classes that need to be importable by Ray workers. |
| 9 | +These classes are used in test_updaters.py but must be defined at module level |
| 10 | +so Ray can serialize and import them on remote workers. |
| 11 | +""" |
| 12 | + |
| 13 | +import torch |
| 14 | +from torchrl._utils import logger |
| 15 | + |
| 16 | + |
| 17 | +class WorkerVLLMNCCL: |
| 18 | + """Ray actor for vLLM inference worker (receiver) using NCCL collective communication.""" |
| 19 | + |
| 20 | + def __init__( |
| 21 | + self, |
| 22 | + scheme_config: dict, |
| 23 | + model_name: str = "Qwen/Qwen2.5-0.5B", |
| 24 | + trainer_actor_name: str = "Trainer", |
| 25 | + ): |
| 26 | + pass |
| 27 | + |
| 28 | + # Store config for deferred initialization |
| 29 | + self.scheme_config = scheme_config |
| 30 | + self.model_name = model_name |
| 31 | + self.trainer_actor_name = trainer_actor_name |
| 32 | + self.wrapper = None |
| 33 | + self.engine = None |
| 34 | + self.receiver = None |
| 35 | + self.scheme = None |
| 36 | + self.trainer = None |
| 37 | + self.model_metadata = None |
| 38 | + |
| 39 | + def setup(self): |
| 40 | + """Set up vLLM engine (deferred from __init__ to avoid blocking).""" |
| 41 | + from torchrl.modules.llm.backends import AsyncVLLM |
| 42 | + from torchrl.modules.llm.policies import vLLMWrapper |
| 43 | + |
| 44 | + # Create vLLM wrapper |
| 45 | + async_engine = AsyncVLLM.from_pretrained( |
| 46 | + self.model_name, |
| 47 | + num_replicas=2, # Number of engine replicas |
| 48 | + ) |
| 49 | + self.wrapper = vLLMWrapper(async_engine, input_mode="history") |
| 50 | + self.engine = self.wrapper.model |
| 51 | + |
| 52 | + # Create scheme from config |
| 53 | + from torchrl.weight_update.llm.vllm_nccl import VLLMWeightSyncScheme |
| 54 | + |
| 55 | + self.scheme = VLLMWeightSyncScheme(**self.scheme_config) |
| 56 | + |
| 57 | + # Create receiver (engine handles rank assignment automatically) |
| 58 | + self.receiver = self.scheme.create_receiver(self.engine) |
| 59 | + return "setup_complete" |
| 60 | + |
| 61 | + def init_metadata(self): |
| 62 | + """Initialize the receiver by fetching metadata from trainer.""" |
| 63 | + import ray |
| 64 | + |
| 65 | + if self.receiver is None: |
| 66 | + raise RuntimeError("Must call setup() before init()") |
| 67 | + |
| 68 | + # Get trainer actor by name |
| 69 | + logger.info(f"Getting trainer actor by name {self.trainer_actor_name}") |
| 70 | + self.trainer = ray.get_actor(self.trainer_actor_name) |
| 71 | + |
| 72 | + # Fetch model metadata from trainer |
| 73 | + logger.info("Fetching model metadata from trainer (requires max_concurrency>1)") |
| 74 | + self.model_metadata = ray.get(self.trainer.get_model_metadata.remote()) |
| 75 | + |
| 76 | + def init(self): |
| 77 | + if self.model_metadata is None: |
| 78 | + raise RuntimeError("Must call init_metadata() before init()") |
| 79 | + |
| 80 | + # Initialize receiver with metadata |
| 81 | + logger.info("Initializing receiver...") |
| 82 | + self.receiver.init_all_workers_group(self.model_metadata) |
| 83 | + self.initialized = True |
| 84 | + logger.info("Receiver initialized") |
| 85 | + return "initialized" |
| 86 | + |
| 87 | + def get_engine(self): |
| 88 | + """Get the vLLM engine reference for RPC coordination.""" |
| 89 | + if self.engine is None: |
| 90 | + raise RuntimeError("Must call setup() first") |
| 91 | + return self.engine |
| 92 | + |
| 93 | + def get_sample_output(self): |
| 94 | + """Get a sample output to verify model works.""" |
| 95 | + # Simple inference test |
| 96 | + return "vllm_ready" |
| 97 | + |
| 98 | + @classmethod |
| 99 | + def as_remote(cls, *args, **kwargs): |
| 100 | + import ray |
| 101 | + |
| 102 | + # No GPUs needed for the actor itself - vLLM workers manage their own placement group (2 GPUs) |
| 103 | + # AsyncVLLM service doesn't act as NCCL rank 0 when used with external trainer |
| 104 | + return ray.remote(num_cpus=4, num_gpus=0, max_concurrency=4)(cls) |
| 105 | + |
| 106 | + |
| 107 | +class WorkerTransformerNCCL: |
| 108 | + """Ray actor for transformer trainer (sender) using NCCL collective communication.""" |
| 109 | + |
| 110 | + def __init__(self, scheme_config: dict, model_name: str = "Qwen/Qwen2.5-0.5B"): |
| 111 | + from torchrl.weight_update.llm.vllm_nccl import ( |
| 112 | + get_model_metadata, |
| 113 | + VLLMWeightSyncScheme, |
| 114 | + ) |
| 115 | + from transformers import AutoModelForCausalLM |
| 116 | + |
| 117 | + # Create transformer model |
| 118 | + transformer = AutoModelForCausalLM.from_pretrained( |
| 119 | + model_name, |
| 120 | + dtype=torch.float16, |
| 121 | + ) |
| 122 | + self.transformer = transformer.cuda() |
| 123 | + |
| 124 | + # Create scheme from config |
| 125 | + self.scheme = VLLMWeightSyncScheme(**scheme_config) |
| 126 | + |
| 127 | + # Create sender |
| 128 | + self.sender = self.scheme.create_sender() |
| 129 | + self.sender.register_model(self.transformer) |
| 130 | + |
| 131 | + # Extract and store model metadata |
| 132 | + self.model_metadata = get_model_metadata(self.transformer) |
| 133 | + |
| 134 | + def init(self, vllm_engine=None): |
| 135 | + """Initialize sender with optional vLLM engine for RPC coordination. |
| 136 | +
|
| 137 | + Args: |
| 138 | + vllm_engine: Optional vLLM engine reference for calling collective_rpc |
| 139 | + """ |
| 140 | + if self.model_metadata is None: |
| 141 | + raise RuntimeError("Must call init_metadata() before init()") |
| 142 | + |
| 143 | + self.sender.init_all_workers_group(self.model_metadata, vllm_engine=vllm_engine) |
| 144 | + self.initialized = True |
| 145 | + logger.info("Trainer initialized") |
| 146 | + return "initialized" |
| 147 | + |
| 148 | + def get_model_metadata(self): |
| 149 | + """Get model metadata to share with receiver.""" |
| 150 | + return self.model_metadata |
| 151 | + |
| 152 | + def update_weights(self, modify_weights: bool = False): |
| 153 | + """Trigger a weight update broadcast. |
| 154 | +
|
| 155 | + Args: |
| 156 | + modify_weights: If True, modifies weights before broadcasting |
| 157 | + for verification purposes. |
| 158 | +
|
| 159 | + Returns: |
| 160 | + str: "updated" status message |
| 161 | + """ |
| 162 | + |
| 163 | + # Optionally modify weights for testing |
| 164 | + if modify_weights: |
| 165 | + with torch.no_grad(): |
| 166 | + first_param = next(self.transformer.parameters()) |
| 167 | + first_param.add_(0.01) |
| 168 | + |
| 169 | + # Broadcast weights to all vLLM workers |
| 170 | + self.sender.update_weights() |
| 171 | + return "updated" |
| 172 | + |
| 173 | + def get_first_param_sum(self): |
| 174 | + """Get sum of first parameter for verification.""" |
| 175 | + return next(self.transformer.parameters()).sum().item() |
| 176 | + |
| 177 | + @classmethod |
| 178 | + def as_remote(cls, *args, **kwargs): |
| 179 | + import ray |
| 180 | + |
| 181 | + return ray.remote(num_cpus=4, num_gpus=1, max_concurrency=4)(cls) |
| 182 | + |
| 183 | + |
| 184 | +class WorkerVLLMDoubleBuffer: |
| 185 | + """Ray actor for vLLM inference worker (receiver) using double-buffered storage.""" |
| 186 | + |
| 187 | + def __init__(self, scheme_config: dict, model_name: str = "Qwen/Qwen2.5-0.5B"): |
| 188 | + # Store config for deferred initialization |
| 189 | + self.scheme_config = scheme_config |
| 190 | + self.model_name = model_name |
| 191 | + self.wrapper = None |
| 192 | + self.engine = None |
| 193 | + self.receiver = None |
| 194 | + self.scheme = None |
| 195 | + |
| 196 | + def setup(self): |
| 197 | + """Set up vLLM engine and receiver.""" |
| 198 | + from torchrl.modules.llm.backends import AsyncVLLM |
| 199 | + from torchrl.modules.llm.policies import vLLMWrapper |
| 200 | + |
| 201 | + # Create vLLM wrapper |
| 202 | + async_engine = AsyncVLLM.from_pretrained( |
| 203 | + self.model_name, |
| 204 | + num_replicas=1, # Single replica for simplicity |
| 205 | + ) |
| 206 | + self.wrapper = vLLMWrapper(async_engine, input_mode="history") |
| 207 | + self.engine = self.wrapper.model |
| 208 | + |
| 209 | + # Create scheme from config |
| 210 | + from torchrl.weight_update.llm.vllm_double_buffer import ( |
| 211 | + VLLMDoubleBufferSyncScheme, |
| 212 | + ) |
| 213 | + |
| 214 | + self.scheme = VLLMDoubleBufferSyncScheme(**self.scheme_config) |
| 215 | + |
| 216 | + # Create receiver |
| 217 | + self.receiver = self.scheme.create_receiver(self.engine) |
| 218 | + logger.info("Receiver setup complete") |
| 219 | + return "setup_complete" |
| 220 | + |
| 221 | + def poll_and_apply_weights(self): |
| 222 | + """Poll for new weights and apply them to the engine.""" |
| 223 | + if self.receiver is None: |
| 224 | + raise RuntimeError("Must call setup() first") |
| 225 | + |
| 226 | + success = self.receiver.poll_and_apply() |
| 227 | + return success |
| 228 | + |
| 229 | + def get_sample_output(self): |
| 230 | + """Get a sample output to verify model works.""" |
| 231 | + return "vllm_ready" |
| 232 | + |
| 233 | + @classmethod |
| 234 | + def as_remote(cls, *args, **kwargs): |
| 235 | + import ray |
| 236 | + |
| 237 | + # vLLM worker needs 1 GPU |
| 238 | + return ray.remote(num_cpus=2, num_gpus=1, max_concurrency=4)(cls) |
| 239 | + |
| 240 | + |
| 241 | +class WorkerTransformerDoubleBuffer: |
| 242 | + """Ray actor for transformer trainer (sender) using double-buffered storage.""" |
| 243 | + |
| 244 | + def __init__(self, scheme_config: dict, model_name: str = "Qwen/Qwen2.5-0.5B"): |
| 245 | + from torchrl.weight_update.llm.vllm_double_buffer import ( |
| 246 | + VLLMDoubleBufferSyncScheme, |
| 247 | + ) |
| 248 | + from transformers import AutoModelForCausalLM |
| 249 | + |
| 250 | + # Create transformer model |
| 251 | + transformer = AutoModelForCausalLM.from_pretrained( |
| 252 | + model_name, |
| 253 | + dtype=torch.float16, |
| 254 | + ) |
| 255 | + self.transformer = transformer.cuda() |
| 256 | + |
| 257 | + # Create scheme from config |
| 258 | + self.scheme = VLLMDoubleBufferSyncScheme(**scheme_config) |
| 259 | + |
| 260 | + # Create sender |
| 261 | + self.sender = self.scheme.create_sender() |
| 262 | + self.sender.register_model(self.transformer) |
| 263 | + logger.info("Trainer setup complete") |
| 264 | + |
| 265 | + def update_weights(self, modify_weights: bool = False): |
| 266 | + """Trigger a weight update by writing to shared storage. |
| 267 | +
|
| 268 | + Args: |
| 269 | + modify_weights: If True, modifies weights before writing |
| 270 | + for verification purposes. |
| 271 | +
|
| 272 | + Returns: |
| 273 | + str: "updated" status message |
| 274 | + """ |
| 275 | + # Optionally modify weights for testing |
| 276 | + if modify_weights: |
| 277 | + with torch.no_grad(): |
| 278 | + first_param = next(self.transformer.parameters()) |
| 279 | + first_param.add_(0.01) |
| 280 | + |
| 281 | + # Write weights to shared storage |
| 282 | + self.sender.update_weights() |
| 283 | + return "updated" |
| 284 | + |
| 285 | + def get_first_param_sum(self): |
| 286 | + """Get sum of first parameter for verification.""" |
| 287 | + return next(self.transformer.parameters()).sum().item() |
| 288 | + |
| 289 | + @classmethod |
| 290 | + def as_remote(cls, *args, **kwargs): |
| 291 | + import ray |
| 292 | + |
| 293 | + return ray.remote(num_cpus=2, num_gpus=1, max_concurrency=4)(cls) |
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