Why Choose Microservice Architecture? A Roadmap and Key Concerns

Why I Chose Microservice Architecture?

It is well known that monolithic applications have many shortcomings and hardly support agile methods. If you want to build a large or complex business software project, it is better to start with a microservice architecture.

Microservice architecture is a flexible design that can significantly improve application flexibility, scalability, and other qualities.

Microservice Architecture Roadmap

Many developers wonder how to begin their microservice journey. Although there are thousands of resources available, they are scattered. I decided to define a roadmap for learning microservices to make the journey clearer.

Basic Idea

Microservice‑based architectures consist of several independent units that work together to receive and process requests. Some parts can be plugins, meaning you can add or remove a plugin without disturbing the overall application.

If you decide to implement a microservice architecture, you should be familiar with various concerns in the application lifecycle, such as persistence, logging, monitoring, load balancing, caching, and know which tools or stacks are best suited for your application.

This article will introduce these concerns from the following aspects:

What is it? Why use it? Which tools are good?

When discussing "which tools are good", I mention a few examples; the selection criteria include business requirements, popularity, performance, open‑source status, and update frequency.

Note: Cloud‑based services are not covered in this article.

The diagram illustrates most components of a standard microservice architecture.

The concerns covered include:

Docker Container Orchestration Docker Container Management API Gateway Load Balancing Service Discovery Event Bus Logging Monitoring and Alerts Distributed Tracing Data Persistence Caching Cloud Providers

Docker

What it is: Docker is an open‑source platform for containerizing applications, bundling the necessary libraries and dependencies so they can run consistently across environments.

Why use it: Docker simplifies and secures the containerization process, making it easier for development teams to package and ship applications.

Which tools are good: Docker

Container Orchestration

What it is: After containerizing an application, you need tools to manage containers, perform manual and automatic operations such as horizontal scaling.

Why use it: Orchestration tools provide services like automatic load balancing and high availability by defining multiple manager nodes that can take over if one fails.

Which tools are good: Kubernetes (K8s), Docker Swarm

Docker Container Management

What it is: Management of Docker environments, configuration, security, etc.

Why use it: GUI‑based tools let users avoid uncomfortable CLI work, offering rich UIs for building and publishing images and simplifying tasks such as horizontal scaling.

Which tools are good: Portainer, DockStation, Kitematic, Rancher

API Gateway

What it is: An API gateway acts as middleware between your services and various clients, handling routing, logging, authorization, performance profiling, and caching.

It works as a reverse proxy, allowing clients to interact with a single entry point while services remain hidden.

Why use it: Without a gateway, each service would need to implement cross‑cutting concerns such as logging and authentication, and clients would have to know every service address.

Which tools are good: Kong, Ocelot

Load Balancing

What it is: Load balancing distributes incoming requests across multiple service instances, enabling scalability and high availability.

Why use it: It allows you to run multiple instances of a service without clients needing to know which instance to call.

Which tools are good: Traefik, NGINX, Seesaw

Service Discovery

What it is: Service discovery provides a registry of service instance addresses, allowing services to locate each other without hard‑coding addresses.

Why use it: Essential when many services exist; it abstracts away the need for each service to know every other service's location.

Which tools are good: Consul, Zookeeper, Eureka, etcd, Keepalived

Event Bus

What it is: In microservices, communication can be synchronous (HTTP/GRPC) or asynchronous via a message or event bus, enabling decoupled interactions.

Why use it: It supports loose coupling and allows new services to subscribe to specific events without direct dependencies.

Which tools are good: RabbitMQ, Kafka

Logging

What it is: Centralized collection of service logs for debugging and analysis.

Why use it: Central logs make it easier to trace a request across multiple services using a unique correlation ID.

Which tools are good: Elastic Stack (Logstash)

Monitoring and Alerts

What it is: Monitoring the functionality, performance, and health of services, and defining early alerts to reduce downtime.

Why use it: Helps identify performance bottlenecks and ensures reliable operation, especially under heavy load.

Which tools are good: Prometheus, Kibana, Grafana

Distributed Tracing

What it is: Tools that trace a request as it flows through multiple services, aiding debugging in a distributed environment.

Why use it: Without tracing, following a request across services is difficult or impossible.

Which tools are good: OpenTelemetry, Jaeger, Zipkin

Data Persistence

What it is: Storing application data in persistent storage, often using a "Database per Service" pattern in microservices.

Why use it: Each service owns its data, accessed only via its API, allowing the use of different databases per service (SQL, NoSQL, graph, etc.).

Which tools are good: Relational: PostgreSQL, MySQL, SQL Server, Oracle; NoSQL: MongoDB, Cassandra, Elasticsearch

Caching

What it is: A high‑speed data store that reduces latency for service‑to‑service communication.

Why use it: Caching can be embedded, client‑server, or reverse‑proxy, and can also be used for rate limiting to protect the system.

Which tools are good: Redis, Apache Ignite, Hazelcast IMDG

Cloud Providers

What it is: Third‑party companies offering cloud platforms, infrastructure, applications, or storage services on a pay‑as‑you‑go basis.

Why use it: Using cloud services avoids the upfront cost and complexity of building and maintaining your own IT infrastructure.

Which tools are good: Amazon Web Services (AWS), Microsoft Azure, Google Cloud, Alibaba Cloud

Conclusion

This article presented a roadmap for microservice architecture. If you want to start from scratch or migrate a monolith to microservices, you need to understand these concepts.

Other topics such as service mesh, additional caching strategies, and persistence are also part of the roadmap but were omitted for simplicity.