One of the often-quoted benefits of using Cloud computing is that you can provide for big bursts of activity by using the flexibility of massive datacentres being built around the world for this. And that if you want to use this service, you simply pay for the bit you use. It means that you can activate a few hundred, or a few thousand, servers in a remote data centre for a day, or a week, or even just a few hours. The kind of examples quoted outside of education include things like the demand for pizzas during the breaks on the Super Bowl Sunday - imagine if you suddenly needed to serve hundreds of thousands of data requests in a huge spike. Other examples that are easy to imagine are retail sites in the run-up to Christmas, or ticket agencies selling concert tickets. The common thread is that need to suddenly provide for a huge spike of interaction, which then drops back within hours or days.
In education there are precise parallels - times of the year (or even of the day) when you need huge amounts of computer capacity, and times of the year when you need almost none:
Before the cloud was here, one of the big costs of any of these systems was the infrastructure - the servers and the networking - needed to support them. It would have cost hundreds of thousands, or millions, to get enough computing to run massive scale student assessments before the cloud - hardware which would sit idle for most of the rest of the year.
But last year in New South Wales, 65,000 students took the formal Science Assessment (called the ESSA test) - all in three days - using the cloud to provide the infrastructure. Instead of buying lots of servers, what they were able to do was to use ‘the Cloud’ - simply activating hundreds of cloud servers to deliver the tests to tens of thousands of students at the same time - over 40,000 by lunchtime the first day. All the students needed was a device with a web-browser. The team at Janison, who worked with the NSW Department of Education and Communities Assessment team, activated 400 servers in our Windows Azure cloud datacentre at 5AM on the day of the first test, and turned them off at 6PM on the last day. And reduced the cost of running the infrastructure from hundreds of thousands to around one thousand dollars.
You can see the dramatic impact of this in the image below - what you’re looking at is a screenshot I took on the first day, from the live monitoring site that was created on the web (it was fascinating to watch the charts updating in real time on the day).
The huge spike happened at 9 o’clock in the morning, as students logged in first thing in the morning to get their tests done. During the day I took a few other screenshots of the metrics as the tests were going, so what I’ll do is post them tomorrow, to give you more info on how the testing went.
Learn more about the Janison CAFE Assessment System used for the ESSA tests