  We can use a hybrid memory system consisting of DRAM and Intel Optane DC
Persistent Memory (We call it DCPM in this paper) as DCPM is now commercially
available since April 2019. Even if the latency for DCPM is several times
higher than that for DRAM, the capacity for DCPM is several times higher than
that for DRAM and the cost of DCPM is also several times lower than that for
DRAM. In addition, DCPM is non-volatile. A Server with this hybrid memory
system could improve the performance for in-memory database systems and virtual
machine (VM) systems because these systems often consume a large amount of
memory. Moreover, a high-speed shared storage system can be implemented by
accessing DCPM via remote direct memory access (RDMA). I assume that some of
the DCPM is often assigned as a shared area among other remote servers because
applications executed on a server with a hybrid memory system often cannot use
the entire capacity of DCPM. This paper evaluates the interference between
local memory access and RDMA from a remote server. As a result, I indicate that
the interference on this hybrid memory system is significantly different from
that on a conventional DRAM-only memory system. I also believe that some kind
of throttling implementation is needed when this interference occures.
