Page 50 - 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

Amazon now offers three different sizes of server to choose
from, small, large, and extra large, something like your choices
at a Starbucks coffee shop. In addition, Amazon throws in two
compute-cycle-intensive variations, which carry out many arith-
metical calculations for each step in a program for applications
that will require above-average use of CPUs or processors.

Once you’ve chosen a size, it’s still possible to add or sub-
tract capacity by activating or deactivating more servers if the
pace at which you want your job to run suddenly demands it.
Amazon Web Services includes CloudWatch, where for an
hourly fee, operational statistics on the servers you designate
to be monitored will be collected. If you subscribe to Cloud-
Watch, then you can also receive Auto Scaling, which will take

the response time information from CloudWatch and auto-
matically scale up or cut back the number of servers you are
using. If you don’t want the maximum wait of site visitors to
exceed 1.5 seconds, then Auto Scaling will keep enough server
availability on hand to maintain that response time.
An additional service that Amazon offers is Elastic Load
Balancing, which distributes incoming application traffic
across the servers that a customer is operating. This service
both spreads the load and detects unhealthy server perfor-

mance, redistributing the workload around such a server until
it can be restored to full operation. Elastic Load Balancing
incurs a charge of 2.5 cents per hour, plus 0.8 cent for each
gigabyte of data transferred, or 8 cents for every 10 gigabytes
through the load balancer. Ten gigabytes is a lot of data; it’s
equivalent to 100 yards of books on a shelf.

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