Say that your online service or web site suddenly gets a 10x increase in users. What is your reaction? If you are in marketing or sales, you are likely overjoyed. If you are in operations, and need to keep the service responding smoothly, you might be rather worried. In particular since everybody, including your users and your CEO, will be quite angry if your service fails to respond in a timely fashion (or at all).
Servers exist to serve. Either they have actively been requested to work, or they sit idle and wait. Their idle time still costs money, though. A cloud application is said to be over-provisioned if there are too many server instances that sit idle, wasting money. When servers are struggling to keep up with demand that is higher than their combined capacity, the application is under-provisioned.
Auto-scaling is the automated process of identifying when an application is either under- or over-provisioned, and trying to rectify the situation by acquiring or releasing machines. Before the cloud, this was a rather lengthy process, taking hours or days to finish. In a cloud environment, however, resources can be easily and quickly provisioned and auto-scaling is therefore one of the main selling points of the cloud.
In this screencast, Lars, who is a Software Architect here at Elastisys, shows how the Elastisys cloud platform can auto-scale a single application across multiple clouds. This multi-cloud capability allows your application to be easily deployed to multiple cloud providers, or multiple regions or zones within a single cloud provider. Do you have customers that would be best served by servers running in both US East and West? Both EU West and Central? This is the fault-tolerant auto-scaling solution for you!