rapidsmpf::bootstrap Namespace Reference

Namespaces
	detail

Classes
struct	Context
	Context information for the current process/rank. More...

Typedefs
using	Rank = std::int32_t
	Type alias for communicator::Rank.

Enumerations
enum class	Backend { AUTO , FILE }
	Backend types for process coordination and bootstrapping. More...

Functions
Context	init (Backend backend=Backend::AUTO)
	Initialize the bootstrap context from environment variables. More...
void	broadcast (Context const &ctx, void *data, std::size_t size, Rank root=0)
	Broadcast data from root rank to all other ranks. More...
void	barrier (Context const &ctx)
	Perform a barrier synchronization across all ranks. More...
void	put (Context const &ctx, std::string const &key, std::string const &value)
	Store a key-value pair in the coordination backend. More...
std::string	get (Context const &ctx, std::string const &key, Duration timeout=std::chrono::seconds{30})
	Retrieve a value from the coordination backend. More...

Detailed Description

SPDX-FileCopyrightText: Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. SPDX-License-Identifier: Apache-2.0

Enumeration Type Documentation

Backend

enum rapidsmpf::bootstrap::Backend

strong

Backend types for process coordination and bootstrapping.

Enumerator
AUTO	Automatically detect the best backend based on environment. Detection order: File-based (default fallback)
FILE	File-based coordination using a shared directory. Uses filesystem for rank coordination and address exchange. Works on single-node and multi-node with shared storage (e.g., NFS) via SSH. Requires RAPIDSMPF_RANK, RAPIDSMPF_NRANKS, RAPIDSMPF_COORD_DIR environment variables.

Definition at line 28 of file bootstrap.hpp.

Function Documentation

barrier()

void rapidsmpf::bootstrap::barrier

(

Context const &

ctx

)

Perform a barrier synchronization across all ranks.

This ensures all ranks reach this point before any rank proceeds.

Parameters

ctx	Bootstrap context.

broadcast()

void rapidsmpf::bootstrap::broadcast	(	Context const &	ctx,
		void *	data,
		std::size_t	size,
		Rank	root = 0
	)

Broadcast data from root rank to all other ranks.

This is a helper function for broadcasting small amounts of data during bootstrapping. It uses the underlying backend's coordination mechanism.

Parameters

ctx	Bootstrap context.
data	Data buffer to broadcast (both input on root, output on others).
size	Size of data in bytes.
root	Root rank performing the broadcast (default: 0).

get()

std::string rapidsmpf::bootstrap::get	(	Context const &	ctx,
		std::string const &	key,
		Duration	timeout = std::chrono::seconds{30}
	)

Retrieve a value from the coordination backend.

This function blocks until the key is available or timeout occurs.

Parameters

ctx	Bootstrap context.
key	Key name to retrieve.
timeout	Timeout duration.

Returns

Value associated with the key.

Exceptions

std::runtime_error

if key not found within timeout.

init()

Context rapidsmpf::bootstrap::init

(

Backend

backend = Backend::AUTO

)

Initialize the bootstrap context from environment variables.

This function reads environment variables to determine rank, nranks, and backend configuration. It should be called early in the application lifecycle.

Environment variables checked (in order of precedence):

• RAPIDSMPF_RANK: Explicitly set rank
• RAPIDSMPF_NRANKS: Explicitly set total rank count
• RAPIDSMPF_COORD_DIR: File-based coordination directory

Parameters

backend

Backend to use (default: AUTO for auto-detection).

Returns

Context object containing rank and coordination information.

Exceptions

std::runtime_error

if environment is not properly configured.

auto ctx = rapidsmpf::bootstrap::init();
std::cout << "I am rank " << ctx.rank << " of " << ctx.nranks << std::endl;

put()

void rapidsmpf::bootstrap::put	(	Context const &	ctx,
		std::string const &	key,
		std::string const &	value
	)

Store a key-value pair in the coordination backend.

This is useful for custom coordination beyond UCXX address exchange.

Parameters

ctx	Bootstrap context.
key	Key name.
value	Value to store.