Problem: bad performance

Verify that the proper interconnect and/or transport is used: check for environment variables controlling transport (see the section called “Controlling ParaStation MPI communication paths” and ps_environment(5)).

Watch protocol counters, e.g. counters indicating timeouts, retries, errors or other bad conditions. For p4sock, check recv_net_data and recv_user. See the section called “ParaStation protocol p4sock.

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