One of the key criteria for Cloud Computing, according to the NIST definition, is “Rapid elasticity”, i.e. “Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand”. The reference architecture for this can be found in Cloud Computing Patterns under the heading of Elastic Component – see Figure 1 below.
Figure 1 – Elastic Component Pattern
The solution is based on a component called a Scaling Manager which monitors the resource utilisation in real-time and, based on a set of metrics and rules, automatically provisions or de-provisions capacity from the resource pool. A good reference implementation for this is Amazon’s CloudWatch shown in Figure 2.
Figure 2 – Amazon’s CloudWatch
Unfortunately, Microsoft do not provide an equivalent in Azure – they just provide the API’s and toolkits for a DIY approach. However, this is where the Microsoft Partner Ecosystem comes into play. Paraleap Technologies is a Chicago-based software company, focused on providing tools and services for cloud computing technologies. AzureWatch is Paraleap’s flagship SaaS product, designed to add dynamic scalability and monitoring to applications running on Microsoft Windows Azure cloud platform. The architecture is shown in Figure 3.
Figure 3 – AzureWatch
Further details can be found at http://www.paraleap.com/AzureWatch.