Page 68 - How Cloud Computing Is Transforming Business and Why You Cant Afford to Be Left Behind

MANA GEMENT STRATEGIES F O R THE CL OUD R EV OL UTION

data center must be built with reliable but inexpensive parts.
Infiniband networks can transport data at 40 gigabits per
second. High-end Ethernet transports it at 10 gigabits per sec-
ond, and these were my candidates for Google’s interconnect
fabric.
Holzle and Barroso say that this can’t be so. Infiniband costs

$500 to $1,000 extra per port, they write. Large-scale Ethernet
moves data at 10 gigabits per second, “but again, at a cost of
hundreds of dollars per server. The alternative is low-cost fab-
rics from commodity Ethernet switches.” I don’t know the
brand name or capacity of the Google cluster switching fabric.
But a highly reliable 1-gigabit Ethernet switch, for example,
costs $148.

The interconnect, like the servers themselves, is built out
of the most proven mass-produced parts. Elasticity is related
to this economy of scale. If you haven’t mastered the art of
building the big server cluster, you will find it hard to deliver
“elastic” service. Remember, you’ve got to do so within the
cloud business model, which demands low prices. How low?
As low as your competitors can go. It’s a tough trade-off. In the
cloud, elasticity is inevitably tied to implementing massive
economies of scale.

Many simple computers built of similar parts can be man-
aged by fewer people. One management interface and a layer
of system management software can scale up to many units,
noting which ones are functioning properly and which ones
are showing signs of heating up, slowing down, or experienc-
ing malfunctioning parts.

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