Maximizing Microservices: Design & Development Strategies

Boost Microservices: Design & Development Strategies

Microservices Concept

Microservices Concept

The Microservices Architecture is made up of a number of uncoupled, compact services.Every service carries out a specific business capacity.These services ought to be cohesive enough to enable autonomous development, testing, release, deployment, scaling, integration, and maintenance.


Determining The Characteristics Of Microservices

  1. Each service is an independent and loosely coupled business unit.
  2. There is a codebase for each service. It is overseen and developed by a small team that works mostly in an agile atmosphere.
  3. Each service is responsible only for one part of functionality (business capability) and performs it well.
  4. The best technology stack can be chosen by each service depending on its needs (there is no need to use the same framework for the entire application).
  5. Each service has a DevOp plan (testing, release, deployment, scaling, integration, and maintenance independently).
  6. Each service is deployed within a self-contained system.
  7. The services communicate using simple protocols such as REST over HTTP and well-defined APIs.
  8. Each service is responsible to persist its own data and maintain external state. (Only when multiple services consume the exact same data are such situations handled by a common data-layer).

Microservices: Benefits and Uses

Microservices are designed to scale large systems. Microservices are also great for continuous delivery and integration.

  1. The Scale Cube concept, described in The Art of Scalability by the great author The Art of Scalability, is supported by Microservices architecture. The application scales automatically via the Y axis when developing microservices for functional decomposition. Microservices that consume a lot of resources can be scaled via the X axis, by cloning them with more CPU and Memory. To distribute data across multiple machines large databases can easily be divided (sharded) into smaller parts that are faster and easier to manage. This allows for the Z axis scale.
  2. Microservices allow for independent releases and deployments. New features and bug fixes are less dangerous and easier to manage. Without needing to redeploy the entire application, update a service. If something goes wrong with an update, you can also roll it back.
  3. Independent development- Each of the services has its own codebase that is developed, tested and deployed by a focused small team. The developers can concentrate on a single service with a relatively small scope.
  4. As a result, there is an uptick in productivity, project speed, ongoing innovation, and source-level quality Graceful degradation - If a service is down, the impact will not spread to the rest and cause a catastrophic failure. This allows a certain level of antifragility to be manifest.
  5. Decentralized governance - Developers can choose the best technology stacks, design standards, and implementation decisions for their services. Teams dont have to be penalized for past technology choices.

Operational Concerns

Independent services cannot create a system. To achieve the full potential of microservices, it is necessary to invest in cross-system concerns such as:

  1. Service replication - a way to scale services based on metadata
  2. Service registration and discovery - a method to enable service lookups and find the endpoints for each service
  3. Service monitoring and logging -- a way to aggregate logs of different microservices, and provide consistent reporting
  4. Resiliency is a system that allows services to take automatic corrective action when they fail.
  5. DevOps is a tool for managing continuous integration and deployment.
  6. API gateway is a way to provide an entry point for users.

Want More Information About Our Services? Talk to Our Consultants!


Middleware & Patterns

Middleware & Patterns

API Gateway

An API gateway serves both clients and microservices by acting as both a central point and edge service to expose APIs managed by managed API providers.

Similar to a reverse proxy, but also providing load balancing, authentication/authorization services as well as failure monitoring/auditing functions as well as protocol translation/routing translation responsibilities - development teams may choose from several approaches when building out their API Gateway solution.

  1. Build it programmatically to get better customization and control
  2. It is possible to deploy an existing API Gateway product, which will save time on initial development and allow you to take advantage of advanced features. (Cons: These products are not free and vendor-dependent. Configuration and maintenance can often be time-consuming and tedious.

Here are some design patterns that describe API Gateway behavior (Read Design Patterns for Microservices).

  1. Gateway Aggregation - aggregates multiple client requests, usually HTTP requests, targeting multiple microservices within a service into a single request. This reduces chattiness between services and consumers.
  2. Gateway Offloading - Allows individual microservices offload shared service functionality at the API gateway. These cross-cutting functions include authentication, authorization and service discovery. They also include fault tolerance mechanisms, load balancing algorithms, logging, analytics, QoS etc.
  3. Gateway Routing - (layer 7, usually HTTP requests) -- route requests to endpoints of microservices internally using a single, central endpoint so that consumers do not need to manage multiple endpoints

It is important to note that the API Gateway component should be highly available and performant, as it is the gateway into the system.


Event Bus (Pub/Sub Mediator Channel For Event-Driven Communication In An Asynchronous Manner)

Event bus offers the ability for different parts of an application to communicate efficiently regardless of language differences (language-agnostic communication) or using different sequences of messages.

Most event buses support publishing/subscribing, distributed point-to-point messages and request/response messaging capabilities - Vert.x supports such connectivity directly between server nodes. Teams that utilize all layers appreciate its powerful functionality.


Service Mesh (Sidecar For Interservice Communication)

Service Mesh provides interservice communication by offering infrastructure that facilitates this communication; its main features are observability (observability of services), security, access control and protocol support.

Developers are free to focus on business capabilities by isolating network communication functions from microservice code using the primitive network functions of Service Mesh.

Essential features, including service discovery, access controls, and observability, can all be provided through the Control Plane installation separately from Service Meshs main installation plan. Service Mesh makes developers lives simpler by helping them focus solely on developing microservice business capabilities instead of taking care of network communication functions directly within the microservice code itself.

Though these images depict direct connections among services, to effectively manage interservice communication, a simple event bus can serve as an intermediary.

By keeping coupling minimal, fewer instances will arise where services must couple with each other directly.


Backends for Frontends (BFF)

If an application requires each API to be tailored specifically for a type of client app (web, mobile or different platforms), specific rules (configs) could be enforced using a facade, or specific builds could be served depending on client capabilities based on an API Gateways service level configuration or in parallel with it; this approach can provide tailored user experiences while keeping BFFs under control.


Best Practices Of Microservices

Best Practices Of Microservices

Domain Driven Design- Provides model services based on the business domain. Domain Driven Design can be used to handle large teams and models.

Domain Driven Design (DDD) deals with large models through the division of them into Bounded Contexts, and by being explicit about interrelationships as well as their underlying domain. These bounded contexts can be separated into microservices during the application design phase.

Decentralized Data Management- (Avoid sharing databases). Multiple services consuming a common data schema can cause tight coupling on the data layer.

To prevent this, each service must have its own data-access logic and a separate data store. Each service can choose the best data persistence method for its data.

Smart endpoints, dumb pipes- Each service has its own API for external communication. Avoid divulging implementation details.

Use simple communication protocols, such as HTTP over REST.

Asynchronous communication- If asynchronous communication across services is used, data flow for other services will not be blocked.

Avoid coupling services- Services should be loosely coupled and have high cohesion. The main reasons for coupling include shared database schemas, rigid communication protocols, and stiff communication protocols.

Decentralize Development- Do not share codebases or data schemas between multiple services/projects. Let developers concentrate on innovation and quality in source code.

Domain knowledge should not be used at the gateway. Let the gateway deal with routing and cross-cutting issues (authentication, SSL Termination).

Token-based Authentication- Implement authentication at the API Gateway using well-known API standards like OAuth2 or OpenID Connect rather than implementing security at the microservices level, which communicate with a central/shared repository for users and retrieve authentication information.

The auth token can be used for communication with other microservices after it is obtained from the auth provider.

Event-driven nature- Humans are autonomous agents who can react to events. Why cant we have systems that are like this?

Strong system- wide consistency is challenging to accomplish because of the high cohesiveness of microservices. The development team must handle eventual consistency issues as they arise.

Fault tolerance- Since the system is composed of many services and middleware, its very easy for a failure to occur.

Implementing patterns such as circuit-breaking and bulkheading, timeouts, retries, failfast, failover caching or rate limiters in these vulnerable components will minimize the risk of failure.

Product engineering- Microservices work best when they are engineered as products, not projects. It is not just about delivering on time and making it work, but a commitment to engineering excellence over the long-term.

Read More: IT Priorities 2023: Software Development


Microservices in Practice

Microservices in Practice

Use Microservices

Microservices architecture is best suited for:

  1. Applications with high-scalability requirements
  2. Projects with a high release velocity
  3. Rich Domains and Multiple Subdomains in Business Cases
  4. Agile environments are small, cross-functional teams that develop large products in collaboration.

Microservices Frameworks That Are Widely Used

  1. Vert.x- light-weight, simple to understand/implement/maintain, polyglot (support many languages), event-driven, non-blocking, so far the best performance and scalability when handling high concurrency needs with minimal hardware, unopinionated (only provides useful bricks, developers have freedom to be innovative and carefully build their applications, not like traditional restrictive frameworks)
  2. Akka- good performance, actor model implemented, suitable for reactive and event-driven microservices
  3. SpringBoot/Cloud- easy to start, familiar paradigms, built on the old Spring framework. A little heavy framework. Many integrations are available. Large community support.
  4. Dropwizard- good for rapid web service development, it comes with a lot of Java libraries and tools, including Google Guava, Jetty server. Logback, Hibernate Validator. Joda Time. Jersey.

Deployment Options

  1. Containers are good for enforcing DevOp goals (rapid application development, reduced time-to-market, seamless scaling).
  2. Cloud computing is useful for creating scalable and dependable infrastructure to service consumers who are spread out worldwide.
  3. Serverless- great for highly volatile traffic
  4. Build your own IT infrastructure- good for those with the resources and capacity to do so

Microservices: Developing Concepts

Microservices: Developing Concepts
  1. Self-Contained System- Assemble software from independent systems, like verticals of microservices
  2. Micro Frontends- separate monolithic web UIs and develop them as independent features. They can communicate directly with microservices.

Top Designing Microservices

Microservice architecture refers to an architecture pattern in which systems are constructed as loosely coupled networks of services.

Microservice architecture makes software that scales independently more manageable, and updates more quickly than monolithic apps.

This tutorial will introduce some design principles for microservices applications which can help create resilient, fault-tolerant, scalable and high performance microservice applications.


Microservices Design Principles

This is a list of key principles that programmers must follow to create microservices based applications which are adaptable and scalable.


Microservices Principle 1: High Cohesion and Low Coupling

Application based on microservices should be highly cohesive with low coupling. This concept stems from the idea that each service should specialize in one task and perform it expertly; consequently, these should have high cohesion while being independent from each other.

Cohesion refers to the degree in which modules functions are linked together closely. High cohesion signifies that all of its functions can be easily comprehended while lower cohesiveness indicates certain modules functions may not be related tightly enough for collective comprehension.

As cohesion increases, so will our understanding of their collective activities; more cohesion means greater cooperation; we could say our modules are working in concert together.

Coupling measures how closely related each module in your programme is; in other words, how closely the different elements fit together.

High coupling means modules are closely connected without much encapsulation whereas low coupling means modules remain separate and isolated from one another - you can test applications when components have loose coupling relationships as well.


Microservices Principle 2: Discrete Boundaries

Microservices are smaller, independently deployable functional units that make scalability and management simpler.

A discrete architecture of microservices features each microservice being accountable for specific tasks.

Imagine creating a web app to allow customers to purchase shoes online. In such an app, one microservice could handle the login process for users while another takes care of the payment and purchase process.

Design your microservices architectural model so as to minimize cross-functional dependencies when developing it.

For example, if your system includes two services that operate separately but depend on each other - say authentication/authorisation services for authentication/authorisation needs to call profile management service to function appropriately - avoid building it so they require each other in order to function.

An API gateway can help relieve this dependency by translating requests from one service into those understood by another service, for instance when called by your profile management service instead of your authentication and authorisation service; then translating those calls so they make sense on both ends - including making sense in terms of authentication/authorisation service requests on either end.


Microservices Principle 3: Single Responsibility Principle

According to the Single Responsibility Principle, classes should only change due to one reason - this principle helps reduce complexity while simultaneously increasing flexibility, extensibility and maintenance - making class switching simpler without disrupting other existing ones.

Reducing conflicts among services by following the Single Responsibility Principle can make updating and maintaining microservices much simpler.

This type of microservice will likely present less likely to require updates.

Programmers must heed this principle when designing microservice-based apps; each microservice must fulfill one function and not assume multiple responsibilities.

Read More: What is the right Approach to Cloud-Based Application Development?


Microservices Principle 4: Design for Failure

The Circuit Breaker Pattern, also referred to as the Circuit Breaker Design Pattern, is a software pattern which helps prevent cascading failures in distributed systems by controlling when services begin intermittently failing without impacting other services in any adverse manner.

Microservices allow other services to continue running normally even if one service becomes inaccessible; other services wont be affected if a failed or offline service affects other services; failures caused by memory leaks or database connection problems shouldnt lead to app failure; instead they should allow other applications to keep functioning normally as intended.

Let us use an example from real-life to illustrate this point: A software developer may maintain both database and application services for their application; should one become unavailable, the other will still function and increase overall availability while decreasing maintenance requirements by relieving broken dependencies more quickly.

As microservice-based applications can function autonomously and independently, you can employ the circuit breaker pattern in order to block communication with any services that dont operate as expected or become inoperable.


Microservices Principle 5: Business Capabilities

Your microservice should be built around business capabilities. Each service should have a responsibility for a particular business capability.

All services should cover the business capabilities required for your application. This principle is important for several reasons.

  1. Keep your service small and manageable. It will be easier to change and understand if each service is only responsible for one capability.
  2. It ensures that the application of a developer is scalable. Developers can scale parts of an application that require more resources by scaling each service independently.
  3. This principle can be used to help designers create more resilient applications.

Even if one service is down, other services will still be able to function and continue to provide business functionality.

It can minimize the impact on users of downtime and outages.


Microservices Principle 6: Decentralization

Microservice applications differ from monolithic apps in that each service maintains its own copy, each microservice having access to its own database; sharing or accessing shared databases would defeat their purpose and nullify them altogether.

Programmers would find it possible to centralize access control while easily incorporating audit logging, caching and caching seamlessly.

Developers too could centralize access while easily incorporating caching and audit logging. In an ideal scenario, there should only be one or two database tables dedicated to each service provided by programmers or developers.


Microservices Principle 7: Process Automation Principle

Microservices architecture is built on the principle of process automation. Programmers can increase reliability, reduce costs and speed software development cycles by automating processes.

As opposed to monolithic apps, microservice-based ones require managing several deployment components; hence it is imperative that their deployment be automated if desired.

One effective approach would be adopting DevOps as part of your culture while using tools like Azure DevOps in this process.


Microservices Principle 8: Inter-Service Communication

As soon as you divide a monolithic application into multiple microservices, communication must take place among them.

How will they do that if their architecture allows for heterogeneous technologies like APIs to use in their communication?

Implementing inter-service communications within microservice architecture can be achieved in several different ways.

One option would be implementing an event-driven architecture where one service publishes an event that another can subscribe to and respond accordingly, or using an event-driven approach where one service publishes events so another service subscribes and can respond.

Programmers need to document all technical information pertaining to their services inner workings and offer API methods so third-party applications may access it directly, thus providing them with the means for gradual expansion without jeopardizing its integrity or its encapsulation.


Microservices Principle 9: Monitoring

Manual processes can be cumbersome when managing microservices applications; for optimal results you require an automated monitoring system to streamline this process.

Microservice architecture complicates monitoring not because there are more moving parts; rather, microservices make this challenge even harder due to being designed independently of each other and often built using various frameworks or technologies; making it hard to know exactly how best to monitor them all together.

Monitoring in a Microservice Architecture differs significantly from monitoring a Monolithic Architecture. Each microservice exists as its own entity, meaning that there may be many instances running at once; as a result, more metrics and logs need to be reviewed by monitoring systems; they must capture this data effectively while also being able to analyze it effectively so they generate useful metrics.


Microservices Principle 10: Command Query Segregation (CQRS)

Traffic to services within a microservices app may fluctuate widely from service to service; one service might experience high usage while others have less.

When this occurs, developers should utilize circuit breaker patterns and auto-scaling.

Command Query Segmentation is an approach for isolating read and write operations into their own operations to enable independent scaling, making this pattern especially helpful in microservice architectures.

CQRS (component-queue-resolver system) is an architectural pattern typically implemented within microservices architecture design.

It allows different components to assume responsibility for different parts of an apps functionality and scale up or maintain without difficulty.

CQRS is a design pattern that restricts data access to one database. When dealing with complex queries spanning many service databases, using CQRS could prove particularly advantageous.

CQRS consists of two parts - command and inquiry components which respectively read statements while creating, editing or deleting those statements, respectively.

This approach offers several advantages. First, it lets you scale reads independently of writes - for instance if your application needs multiple writes but few reads, multiple instances of the reading layer might make more sense than only having one instance for the writing layer.

Furthermore, maintaining data integrity becomes simpler with every class taking responsibility for their part, making testing simpler as each responsibility has only one target rather than multiple targets as is usually found with relational databases.

Want More Information About Our Services? Talk to Our Consultants!


The Conclusion Of The Article Is:

Microservice architecture refers to an architecture strategy for distributed design that strives to bypass monolithic designs by breaking them up into smaller components called microservices.

Microservices architecture speeds cycle times while helping organizations and applications scale - but can present additional operational burden and architectural complexities as a downside.


References

  1. 🔗 Google scholar
  2. 🔗 Wikipedia
  3. 🔗 NyTimes