PITAGORA: change to the settings of the Intel-oneapi-mpi modules

Dear EuroFusion users,
this is to inform you that, after a period of test and validation, a new setting has been added to the module “intel-oneapi-mpi/2021.12.1”:
export UCX_TLS=^rc
This setting replaces the previous:
export FI_PROVIDER=verbs
and re-enables Mellanox (MLX) as the default provider for Intel-oneapi-mpi, eliminating an UCX trasport layer that was causing communication problems to most applications well used by the EuroFusion community, for certain configuration of number of nodes / MPI tasks. We expect this new configuration to be beneficial to the performance and stability of a large number of use cases that experienced problems with the previous settings.

The Userguide has been updated accordingly:
https://docs.hpc.cineca.it/hpc/pitagora.html#known-issues
along with some additional informations and instructions on how to manually setup the specific variables in case you are in need of testing different solutions.

If you encounter any problem with this configuration, please write at [email protected] for support.

Best regards,
HPC User Support – CINECA