2. Azure solution availability, scalability, and monitoring

Architectural concerns, such as high availability and scalability, are some of the highest-priority items for any architect. This is common across many projects and solutions. However, this becomes even more important when deploying applications to the cloud because of the complexity involved. Most of the time, the complexity does not come from the application, but from the choices available in terms of similar resources on the cloud. The other complex issue that arises from the cloud is the constant availability of new features. These new features can almost make an architect's decisions completely redundant in hindsight.

In this chapter, we will look at an architect's perspective in terms of deploying highly available and scalable applications on Azure.

Azure is a mature platform that provides a number of options for implementing high availability and scalability at multiple levels. It is vital for an architect to know about them, including the differences between them and the costs involved, and finally, be in a position to choose an appropriate solution that meets the best solution requirements. There is no one solution for everything, but there is a good one for each project.

Running applications and systems that are available to users for consumption whenever they need them is one of the topmost priorities for organizations. They want their applications to be operational and functional, and to continue to be available to their customers even when some untoward events occur. High availability is the primary theme of this chapter. Keeping the lights on is the common metaphor that is used for high availability. Achieving high availability for applications is not an easy task, and organizations have to spend considerable time, energy, resources, and money in doing so. Additionally, there is still the risk that an organization's implementation will not produce the desired results. Azure provides a lot of high-availability features for virtual machines (VMs) and the Platform as a Service (PaaS) service. In this chapter, we will go through the architectural and design features that are provided by Azure to ensure high availability for running applications and services.

In this chapter, we will cover the following topics: