Datawarehouse- Case study in cloud computing

Our second case study analyzes the cost of providing DR
for a Data Warehouse application. A data warehouse
records data such as a stream of website clicks or sales
information produced by other applications. Data is typically
appended to the warehouse at regular intervals, and
reports are generated based on the incoming and existing
data sets. We consider a small sized Data Warehouse
with a 1TB capacity that adds 1 GB of new data per day.
To run the full application, a powerful server is required–
we estimate costs based on a “High-Memory Extra Large
Instance” from EC2.
Cost Breakdown: Figure 3(a) shows the cost for running
the data warehouse application. We assume that the
cloud based DR system requires a “medium” size VM
as a backup server due to its IO intensive nature, resulting
in a relatively high server cost even under normal operation.
Additionally, the cloud must pay a large storage
cost to support the 1TB capacity of the data warehouse.
As a result, the cloud based DR service provides a
smaller benefit because its Replication Mode cost is only
slightly lower than the cost in a colocation facility, and
its Failover Mode cost is significantly higher.

99% Uptime Cost: By comparing the Failover Mode
costs, it is clear that it is cheapest to use a colocation
center as the primary site of the data warehouse ($5,853
per year in the cloud versus $3,202 per year in a colocation
center). However, since the replication cost for the
cloud is lower and is incurred for 99% of the time, the
total costs is still lower for the cloud. Despite having a
higher Failover Mode price, the cloud based DR system
still lowers the total DR cost from $3,186 to $2,832 over
a one year period assuming 99% uptime.