NCCL Experiment Repository

This repository contains documentation and implementations for three major projects:

CRAC Documentation

CRAC (Checkpoint/Restart As a C library) provides checkpoint/restart functionality for HPC applications.

DMTCP Documentation

DMTCP (Distributed MultiThreaded Checkpointing) provides transparent checkpoint/restart functionality for distributed applications.

MANA Documentation

MANA: MPI-Agnostic, Network-Agnostic Transparent Checkpointing

The checkpointing process in MANA follows a carefully orchestrated multi-phase approach to ensure application state consistency while maintaining transparency.

Process Flows

Restart Process Flow

The restart process reconstructs the entire application state from checkpoint files while potentially using different MPI implementations or network fabrics.

MPI Call Interception Flow

Every MPI call goes through MANA's interception layer to provide transparency and enable checkpointing.

Virtual Object Management Flow

Virtual objects enable MANA's MPI/network agnosticism by abstracting implementation details.