Resilient microservices and reliable applications

Progressively, the world is connected and software-enabled. We often hear, read, and experience software-defined computing, storing, and networking capabilities. Physical, mechanical, electrical, and electronics systems in our everyday environments are being meticulously stuffed with software to be adroit, aware, adaptive, and articulate in their actions and reactions. Software is destined to play a strategic and significant role for producing and sustaining digitally impacted and transformed societies, one stand-out trait of new-generation software-enabled systems are responsive all the time through one or other ways. That is, they have to come out with a correct response. If the system is not responding, then another system has to respond correctly and quickly. That is, if a system is failing, an alternative system has to respond.

This is typically called system resiliency. If the system is extremely stressful due to heavy user and data loads, then additional systems have to be provisioned to respond to user's requests without any slowdown and breakdown. That is, auto-scaling is an important property for today's software systems to be right and relevant for businesses and users. This is generally called system elasticity. To make systems resilient and elastic, producing message-driven systems is the key decision. Message-driven systems are called reactive systems. Let's digress a bit here and explain the concepts behind system resiliency and elasticity.

A scalable application can scale automatically and accordingly to continuously function. Suddenly, there can be a greater number of users accessing the application. Still, the application has to continuously transact and can gracefully handle traffic peaks and dips. By adding and removing virtual machines and containers only when needed, scalable applications do their assigned tasks without any slowdown or breakdown. By dynamically provisioning additional resources, the utilization rate of scalable applications is optimal. Scalable applications support on-demand computing. There can be many users demanding the services of the application, or there can be more data getting pushed into the application. Containers and virtual machines are the primary resource and runtime environment for application components.