  Dynamic scaling aims to elastically change the number of processes during
runtime to tune the performance of the distributed applications. This report
briefly presents a performance evaluation of MPI process provisioning /
de-provisioning for dynamic scaling by using 16 to 128 cores. Our dynamic
scaling implementation allows the new MPI processes from new hosts to
communicate with the original ones immediately. Moreover, it forbids the
removing MPI processes to communicate with others as well as gets the
information whether the host node can be terminated or not. Such a simple
feature is not supported as a single-line API in MPI-2 such as
MPI_Comm_spawn(). We provide our implementation as a simple library to extend a
non-dynamic-scalable MPI program into a dynamic-scalable one by adding only
several lines of codes.
