Let's talk of Reactive Architecture
Tags: architecture, design, softwaredevelopment, devops
Published: 2024-03-03 20:00:25

Let's imagine a world where we build applications not only with the aim of these working well but also handling a lot of users smoothly, even when things get busy. That's what Reactive Architecture is all about. It's just like creating a smart system that knows how to manage lots of information at once, without slowing down or crashing. This way, everyone using the app has a great experience, no matter how many people online or how much data is being used. That is what bring me here, pay attention for a few minutes, the time to empty your cup of coffee we will be done.

## Small Story
![Story time gif](https://i.pinimg.com/originals/d0/e4/cd/d0e4cd0cc8f144809c112bdd35098542.gif)
Imagine it's November 25, 2020, and you're going about your day when suddenly, you can't access your favorite tools and platforms online. Adobe won't load, your Roku streaming is glitching, Twilio-based apps aren't sending messages, Duolingo isn't teaching languages, and even planning an in-person meetup using Meetup feels like a distant dream. To top it off, New York City's Metropolitan Transit Authority is also facing tech hiccups. Why? Because AWS, a giant upon which the digital world leans, experienced an outage.

This wasn't just any outage. It was the kind that reminded everyone of a similar hiccup back in 2017, which also sent waves of disruption across the internet. Both instances shone a spotlight on a truth we often forget: our vast, intricate digital ecosystem is more interconnected than we realize. A snag in one corner can send ripples across the entire pond, affecting services and sectors far and wide.

Reflecting on the 2020 AWS outage is like peering into a digital mirror, revealing our collective reliance on cloud services and the vulnerabilities that come with this dependence. Despite tech advances and beefed-up infrastructures, the incident underscored a lingering question: How do we safeguard our digital lives against such outages? It pushed companies to think harder about having backup plans and highlighted the broader conversation about the centralization of internet services and the risks this centralization poses to our digital society.

In essence, the AWS outage of 2020 was more than just a technical glitch; it was a moment of realization about the fragile web that supports our digital world and a call to action for ensuring its strength and resilience.

## What is Reactive Architecture?
![Thinking meme gif](https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExeG1raWR1MzJoNDdpMmhxbmRvZTJvbXR4dWp5OGRrOGd6bTIxZ3c5eSZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/d3mlE7uhX8KFgEmY/giphy.gif)

At its core, Reactive Architecture is designed to create non-blocking, asynchronous applications that are capable of handling a vast number of concurrent data streams and operations. This approach not only enhances performance but also improves the user experience by ensuring responsive and resilient interactions.

Reactive Architecture isn't just about building applications; it's about crafting experiences that feel alive. Imagine apps that breathe with the pulse of user interaction, systems that not only respond to demands but anticipate them, creating a seamless flow of information. This is technology that doesn't just serve; it engages, adapts, and excites, transforming the digital landscape into a dynamic ecosystem where performance and user experience converge in harmony.

## Why Reactive Systems?
![Why Meme](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/hyx2zdc4rjqwzbhqoga1.png)
Simply because **"Today’s demands are simply not met by yesterday’s software architectures"**, the landscape of software development has undergone a dramatic transformation. This shift is driven by the increased scale of deployments, the exponential growth in data volume, the need for rapid feature updates, and the expectation of flawless availability and lightning-fast response times. Modern software must be resilient, scalable, and quick to recover, catering to a user base that depends heavily on digital services for their daily activities and tolerates little to no downtime. This evolution underscores the critical need for architectures that can adeptly handle these modern complexities.

## Pillars of Reactive Systems:
![Reactive Manifesto](https://www.reactivemanifesto.org/images/reactive-traits.svg)

Reactive Systems are built around four key principles to ensure they meet the demands of modern applications:

- **Responsiveness**: They aim for quick and consistent reactions to user requests, ensuring usability and utility. By maintaining steady response times, these systems can quickly identify and address issues, enhancing user confidence and interaction.

- **Resilience**: Even in case of failure, these systems remain operational, utilizing strategies like replication, containment, isolation, and delegation to prevent system-wide breakdowns. This approach allows individual components to fail and recover without affecting the overall system's availability.

- **Elasticity**: They adapt to workload changes without compromising responsiveness, by dynamically adjusting resources. This flexibility is achieved through designs that avoid bottlenecks, allowing for scalable and efficient operation on standard hardware and software.

- **Message-Driven**: Communication within these systems is based on asynchronous message-passing, which minimizes dependencies and simplifies management of failures and resource consumption. This method supports effective load management and system efficiency.

## Pros and Cons
Let's evaluate the good and bads of this type of systems.
![Choices meme](https://cdn.memes.com/up/59166011670362224/i/1670435341460.jpg)

| Pros | Cons |
|------|------|
| **Responsive**: Ensures quick and consistent response times, improving usability and user satisfaction. | **Complexity**: The asynchronous nature and message-driven approach can increase the complexity of system design and debugging. |
| **Resilient**: Remains operational even in the face of failures through strategies like replication and isolation. | **Learning Curve**: Requires a shift in mindset from traditional programming approaches, which can be challenging for teams to adopt. |
| **Elastic**: Can dynamically adjust resources based on workload, promoting efficient resource use. | **Tooling and Support**: While improving, the ecosystem for reactive programming may still lack in comparison to more traditional models, potentially affecting development and operational tools. |
| **Message-Driven**: Facilitates loose coupling and enhances scalability and failure management through asynchronous message-passing. | **Testing**: Testing reactive systems can be more complex due to their asynchronous and non-blocking nature. |

## Event Driven Architecture vs Reactive systems
![VS memev-to-uploads.s3.amazonaws.com/uploads/articles/czmw49otc7toc6copvb9.png)

To compare these systems, we need to do some highlights in their approaches to handling data and system interactions. Alot of talking let's get more about.

- **Responsiveness and Flow Control**: EDA focuses on decoupling system components through events, allowing for dynamic and flexible application responses. Reactive Systems, while also emphasizing decoupling, prioritize controlled flow and backpressure, ensuring systems do not become overwhelmed by data.

- **System Design and Complexity**: EDA simplifies integration and extension by using events as a means of communication. Reactive Systems introduce additional complexity with their emphasis on non-blocking communication and backpressure, requiring a more thorough understanding of these concepts for effective implementation.

- **Failure Management**: Both architectures aim to enhance system resilience. EDA does so by isolating failures to the event level, whereas Reactive Systems offer a more structured approach to failure management through explicit message passing and backpressure, aiming to prevent failures from cascading.

- **Scalability**: EDA naturally supports scalability through its loosely coupled nature. Reactive Systems take this further by addressing scalability in the context of system load, offering mechanisms like dynamic resource management to maintain performance under varying conditions.

## Cutting the 'T' and dotting the 'i'
In conclusion, both Event-Driven Architecture and Reactive Systems offer powerful paradigms for building scalable, resilient applications. EDA excels in decoupling components for flexibility and scalability, while Reactive Systems provide robust mechanisms for handling data flow and system load, ensuring responsive and resilient applications. The choice between them hinges on the specific requirements of your project, including scalability needs, complexity tolerance, and the importance of flow control and backpressure in maintaining system stability.