validated against those from measurements on the 16 node cluster. This provided us
with an accurate platform to experiment with server design alternatives.
We analyze four server designs (PRESS over VIA, coscheduled PRESS with DCS,
coscheduled PRESS with DCS and blocking, and Adaptive) using a 32 node configura
tion. Our results shows that the DCS coscheduling algorithm can reduce the average
latency up to four times in lightly loaded servers compared to the PRESS over VIA
model. The adaptive model yields a gain in performance by applying the DCS coschedul
ing algorithm selectively depending the server load. With the DCS Blocking scheme, the
latency reduction is less because of the blocking overhead.
The rest of this chapter is organized as follows. In Section 2, we provide a sum
mary of the PRESS model and coscheduling techniques. Section 3 and Section 4 outline
the proposed coscheduled server to the PRESS Web model and the simulation plat
form respectively. The performance results are analyzed in Section 5, followed by the
concluding remarks in the last Section.