  MANA-2.0 is a scalable, future-proof design for transparent checkpointing of
MPI-based computations. Its network transparency ("network-agnostic") feature
ensures that MANA-2.0 will provide a viable, efficient mechanism for
transparently checkpointing MPI applications on current and future
supercomputers. MANA-2.0 is an enhancement of previous work, the original MANA,
which interposes MPI calls, and is a work in progress intended for production
deployment. MANA-2.0 implements a series of new algorithms and features that
improve MANA's scalability and reliability, enabling transparent
checkpoint-restart over thousands of MPI processes. MANA-2.0 is being tested on
today's Cori supercomputer at NERSC using Cray MPICH library over the Cray GNI
network, but it is designed to work over any standard MPI running over an
arbitrary network. Two widely-used HPC applications were selected to
demonstrate the enhanced features of MANA-2.0: GROMACS, a molecular dynamics
simulation code with frequent point-to-point communication, and VASP, a
materials science code with frequent MPI collective communication. Perhaps the
most important lesson to be learned from MANA-2.0 is a series of algorithms and
data structures for library-based transformations that enable MPI-based
computations over MANA-2.0 to reliably survive the checkpoint-restart
transition.
