Windows Azure is changing. A lot of new features were released and existing one were improved. In this post I want to talk about one thing that was changed on Azure – the billing model.
Until now the paying granularity was per hour. This means that if I use a web-role for 30 minutes, then I would pay for an hour. If I use it for 1 hour and 1 minutes, then I would pay for 2 hours. Because other cloud providers offer services with per-minute granularity, Microsoft also decided to change the granularity to minutes.
This is great, you will pay only the time when you use a compute resource like web-roles, worker-roles, VMs, Mobile Services and so on). For classic application that use Azure for hosting and don’t scale (up and down) for short period of time this change will not affect the bill value at the end of the month – we will have the same flat value.
The true value of per-minute will be for application that scale up for very short period of time. For example we have a scenario where a client needs to process tens of millions of requests in a very short period of time. For example we want to process all this requests in 6 minutes – this task would repeat every day.
For this case when you need to scale for a very short period of time, a per-minutes payment solution is perfect. We can have for the same price 30 worker-roles that process the request instead of 10 or 15.
BUT, be aware of one thing – DON’T FORGET THAT YOU PAY FROM THE MOMENT WHEN THE INSTANCE STARTED AND THE DEPLOYMENT RUN ON THAT SPECIFIC INSTANCE.
This means that if you have a 6 minute job on the instance plus 10 minutes to start the instance and deploy your solution plus maybe 1 or 2 minute to stop the machine you will end up with 17-18 minutes. Is better then paying for a full hour, but we need to take care of this aspect when we prepare a cost estimation.
In conclusion, this change is great and give us the possibility to scale more with the same cost.