Availability in current cloud computing services

This article reports research performed in Australia looking at the availability of cloud services provided by Amazon, Google and Microsoft. Here is how the experiment was set up:

The team of researchers, led by the University of New South Wales (UNSW) and in collaboration with researchers at NICTA (National ICT Australia) and the Smart Services Cooperative Research Centre (CRC), have spent seven months stress testing Amazon's EC2, Google's AppLogic and Microsoft's Azure cloud computing services.

The analysis simulated 2000 concurrent users connecting to services from each of the three providers, with researchers measuring response times and other performance metrics.

Here are some things they found:

Response times on the service also varied by a factor of twenty depending on the time of day the services were accessed, she said.

The response times collated in Sydney were tested against measurement instruments loaded onto the cloud platform to isolate whether delays were attributable to the service itself or the latency involved with accessing US-based data centres from Australia.

and

None of the platforms have the kind of monitoring required to have a reasonable conversation about performance," she said. "They provide some level of monitoring, but what little there is caters for developers, not business users. And while Amazon provides a dashboard of how much it is costing you so far, for example, there is nothing in terms of forecasts about what it will cost you in the future.