Multi-SPMD Programming Model with YML and XcalableMP
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Fig. 3 An example of “Implementation” in YML
a grid environment, the OmniRPC backend linked with the OmniRPC middleware
library should be loaded.
The OmniRPC [9] is a grid RPC facility for cluster systems. The OmniRPC
supports a master-worker programming model, where remote serial programs (rexs)
are executed by exec, rsh or ssh.
To realize the mSPMD programming model, we have implemented an MPI
backend and extended the OmniRPC to OmniRPC-MPI for a large scale cluster
environment. The OmniRPC-MPI library provides the following functions:
• invoke a remote program (worker program) over a specified number of nodes.
• communication between the workflow scheduler and the remote programs.
– the scheduler sends a request to execute a certain task to a remote program.
– the scheduler listens to the communicator and receives a termination message
from a remote program.
• manage remote programs and computational resources.