Source code for torch.distributed.rpc

from datetime import timedelta
import logging
import threading
import warnings
from typing import Generator, Tuple

import torch
import torch.distributed as dist

logger = logging.getLogger(__name__)

_init_counter = 0
_init_counter_lock = threading.Lock()

def is_available():
    return hasattr(torch._C, "_rpc_init")

if is_available() and not torch._C._rpc_init():
    raise RuntimeError("Failed to initialize torch.distributed.rpc")

if is_available():
    from torch._C._distributed_c10d import Store
    from torch._C._distributed_rpc import (
    )  # noqa: F401

    from . import api, backend_registry, functions
    from .api import *  # noqa: F401,F403
    import numbers

    import torch.distributed.autograd as dist_autograd

    from .backend_registry import BackendType
    from .options import TensorPipeRpcBackendOptions  # noqa: F401
    from .server_process_global_profiler import (

    rendezvous_iterator: Generator[Tuple[Store, int, int], None, None]

[docs] def init_rpc( name, backend=None, rank=-1, world_size=None, rpc_backend_options=None, ): r""" Initializes RPC primitives such as the local RPC agent and distributed autograd, which immediately makes the current process ready to send and receive RPCs. Args: name (str): a globally unique name of this node. (e.g., ``Trainer3``, ``ParameterServer2``, ``Master``, ``Worker1``) Name can only contain number, alphabet, underscore, colon, and/or dash, and must be shorter than 128 characters. backend (BackendType, optional): The type of RPC backend implementation. Supported values is ``BackendType.TENSORPIPE`` (the default). See :ref:`rpc-backends` for more information. rank (int): a globally unique id/rank of this node. world_size (int): The number of workers in the group. rpc_backend_options (RpcBackendOptions, optional): The options passed to the RpcAgent constructor. It must be an agent-specific subclass of :class:`~torch.distributed.rpc.RpcBackendOptions` and contains agent-specific initialization configurations. By default, for all agents, it sets the default timeout to 60 seconds and performs the rendezvous with an underlying process group initialized using ``init_method = "env://"``, meaning that environment variables ``MASTER_ADDR`` and ``MASTER_PORT`` need to be set properly. See :ref:`rpc-backends` for more information and find which options are available. """ torch._C._log_api_usage_once("torch.distributed.init_rpc") if backend is not None and not isinstance( backend, backend_registry.BackendType ): raise TypeError("Argument backend must be a member of BackendType") if rpc_backend_options is not None and not isinstance( rpc_backend_options, RpcBackendOptions ): raise TypeError( "Argument rpc_backend_options must be an instance of RpcBackendOptions" ) # Try to detect the backend from the options if backend is None and rpc_backend_options is not None: for candidate_backend in BackendType: if isinstance( rpc_backend_options, type( backend_registry.construct_rpc_backend_options( candidate_backend ) ), ): backend = candidate_backend break else: raise TypeError( f"Could not infer backend for options {rpc_backend_options}" ) # Ignore type error because mypy doesn't handle dynamically generated type objects (#4865) if backend != BackendType.TENSORPIPE: # type: ignore[attr-defined] logger.warning( f"RPC was initialized with no explicit backend but with options " # type: ignore[attr-defined] f"corresponding to {backend}, hence that backend will be used " f"instead of the default {BackendType.TENSORPIPE}. To silence this " f"warning pass `backend={backend}` explicitly." ) if backend is None: backend = BackendType.TENSORPIPE # type: ignore[attr-defined] if rpc_backend_options is None: # default construct a set of RPC backend options. rpc_backend_options = backend_registry.construct_rpc_backend_options( backend ) # Rendezvous. # This rendezvous state sometimes is destroyed before all processes # finishing handshaking. To avoid that issue, we make it global to # keep it alive. global rendezvous_iterator rendezvous_iterator = dist.rendezvous( rpc_backend_options.init_method, rank=rank, world_size=world_size ) store, _, _ = next(rendezvous_iterator) # Use same timeout as RPC. store.set_timeout(timedelta(seconds=rpc_backend_options.rpc_timeout)) # Use a PrefixStore to distinguish multiple invocations. with _init_counter_lock: global _init_counter store = dist.PrefixStore(str("rpc_prefix_{}".format(_init_counter)), store) _init_counter += 1 # Initialize autograd before RPC since _init_rpc_backend guarantees all # processes sync via the store. If we initialize autograd after RPC, # there could be a race where some nodes might have initialized autograd # and others might not have. As a result, a node calling # torch.distributed.autograd.backward() would run into errors since # other nodes might not have been initialized. dist_autograd._init(rank) _set_profiler_node_id(rank) # Initialize RPC. _init_rpc_backend(backend, store, name, rank, world_size, rpc_backend_options)
def _validate_rpc_args(backend, store, name, rank, world_size, rpc_backend_options): type_mapping = { backend: backend_registry.BackendType, store: dist.Store, name: str, rank: numbers.Integral, world_size: numbers.Integral, rpc_backend_options: RpcBackendOptions, } for arg, arg_type in type_mapping.items(): if not isinstance(arg, arg_type): raise RuntimeError( "Argument {} must be of type {} but got type {}".format( arg, arg_type, type(arg) ) ) def _init_rpc_backend( backend=BackendType.TENSORPIPE, # type: ignore[attr-defined] store=None, name=None, rank=-1, world_size=-1, rpc_backend_options=None, ): _validate_rpc_args(backend, store, name, rank, world_size, rpc_backend_options) if _is_current_rpc_agent_set(): raise RuntimeError("RPC is already initialized") # Initialize RPC. rpc_agent = backend_registry.init_backend( backend, store=store, name=name, rank=rank, world_size=world_size, rpc_backend_options=rpc_backend_options, ) api._init_rpc_states(rpc_agent) @api._require_initialized def _get_debug_info(): info = _rref_context_get_debug_info() info.update(api._get_current_rpc_agent().get_debug_info()) info.update(dist_autograd._get_debug_info()) return info


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