Challenges of building distributed systems on warehouse-scale computers

Running a system on warehouse-scale computers, distributed across multiple data centres (perhaps on multiple continents), raises the following challenges:

• Single points of failure—hardware or software—can take the whole system down.
• Clocks from different machines or data centers will not agree.
• Data replicated at multiple locations may differ for each reader.
• Information takes substantial time to transmit long distances.
• Some governments require some data to be stored in specific geographic regions.
• Warehouse-scale computers have different performance bottlenecks than single servers.
• Demand can change suddenly and with little warning.