Today’s requirements demand new technologies as applications are deployed on multiple devices (mobile, tabs, cloud), with each of the machines having thousands of multicore processors. The user expectation on the response time is in millisecond, or even micro-second. The systems are expected to be up 100% of the time and churn big data (petabytes).
In summary today’s problems are far bigger in scale as well as in complexity as compared to those in the recent past.This calls for some changes to the design principles to be applied well in advance. One such approach is listed in The Reactive Manifesto by summarising the key principles of how to design highly scalable and reliable applications.
The Reactive Manifesto
In 2013 a group of individuals came up with the collection of design principles that would help build systems that are responsive, maintainable, elastic and scalable from the outset. This collection of design principles was published as a manifesto called as The Reactive Manifesto.
The manifesto attempts to summarize the information on how to design highly scalable and reliable applications. These are listed as architecture best practices and also define a common vocabulary to easy communication while discussing these topics like architecture and scalability among various stakeholders like engineering managers, developers, architects, CTOs.
High Level Traits
The reactive systems exhibit four high-level traits: Responsive, Resilient, Elastic and Message Drive.
A reactive system will be responsive meaning it will react to users in timely manner. For the users, when the response time exceeds their expectation, the system is down.
A resilient system keeps processing transactions, even when there are transient impulses, persistent stresses, or component failures disrupting normal processing. This is what most people mean when they just say stability.
Resilient systems are loosely coupled in order to achieve high degree of resilience. This is achieved with a shared-nothing architecture, clear boundaries and use of Microservices that lead to single responsibility independent components.
Elasticity plays a major role in Scalability. A reactive system would Scale Up for responding to increase in number of users and will scale down to save cost as the number of system users decreases.
A resilient system keeps processing transactions, even when there are transient impulses, persistent stresses, or component failures disrupting normal processing. This is what most people mean when they just say stability.
Resilient systems are loosely coupled in order to achieve high degree of resilience. This is achieved with a shared-nothing architecture, clear boundaries and use of Microservices that lead to single responsibility independent components.
Elasticity plays a major role in Scalability. A reactive system would Scale Up for responding to increase in number of users and will scale down to save cost as the number of system users decreases.
Reactive Systems are more flexible, loosely-coupled and scalable. They are easier to develop and open to change. They are significantly more tolerant of failure. Reactive Systems are highly responsive, giving users effective interactive feedback.
The manifesto is aimed at end-user projects as well as for reusable libraries and frameworks. One can look at the manifesto as a dictionary of best practices.
The long term advantage that this manifesto provides is to come up with a set of principles to avoid confusion and facilitate on-going dialog and improvement for scalable, resilient and responsive systems.
The Reactive Manifesto is about effectively modelling the use cases in our problem domain, writing solutions that will scale and live up to the customers’ expectations. The reactive characteristics can be considered as a list of service requirements.
The requirements of a system need to be captured and factored into a design right at the onset and the reactive manifesto allows one to have the characteristics in one place. This allows one to check if the particular characteristic is applicable to their system.
The manifesto is aimed at end-user projects as well as for reusable libraries and frameworks. One can look at the manifesto as a dictionary of best practices.
The long term advantage that this manifesto provides is to come up with a set of principles to avoid confusion and facilitate on-going dialog and improvement for scalable, resilient and responsive systems.
The Reactive Manifesto is about effectively modelling the use cases in our problem domain, writing solutions that will scale and live up to the customers’ expectations. The reactive characteristics can be considered as a list of service requirements.
The requirements of a system need to be captured and factored into a design right at the onset and the reactive manifesto allows one to have the characteristics in one place. This allows one to check if the particular characteristic is applicable to their system.
