Microservices are small, discrete chunks of functionality which interact with other microservices to create a larger system. Almost all computer systems perform multiple tasks by using shared resources. Computer programming uses the concept of microservices where close bits of codes perform tasks tied to one another.
The way microservices are implemented makes them a natural foundation for modern cloud-based applications. Also, microservices dovetail with the DevOps philosophy, which encourages new functionality continuously and rapidly.
What exactly are Microservices?
The word ‘micro’ in Microservices tells us that these are small applications. A better way to think about them is that they should be only as big as needed to do one particular thing or solve a specific problem, keeping in mind that the problem should be conceptual, not technical. Microservices communicate with other microservices and outside users through comparatively stable APIs to create a larger application. As quoted by Microsoft, “Microservices should be designed around business capabilities, not horizontal layers such as data access or messaging”.
Thus, the internal functionality of an individual microservice can be radically upgraded without affecting the rest of the system which in turn ties with how DevOps shops seek to operate. If a part of a larger application’s particular functions is segmented out into discrete, independently operating pieces of code, it’s easier to live the DevOps strategy of CI/CD (Continuous Integration and Continuous Delivery). Moreover, well-developed APIs make Microservices easy to test automatically.
Features of Microservices
- Microservices are Agile: they can develop and discard any new feature at the same time.
- Shows Resiliency: Functionality dispersion across multiple services eliminates susceptibility to a single point of failure.
- They are Profitable: Faster iterations and decreased downtime can increase revenue.
- Shows Flexibility: To build various services of the same application, different languages and technologies can be used.
- Decoupling: All services can be easily built and scaled.
- Shows Responsibility: Microservices treat each application as a separate, self-sufficient unit.
- Independent: Teams work independently of each other.
- Continuous delivery: Microservices allow the frequent release of software and upgrades.
What are the Approaches to Start Developing Microservices?
When it comes to Microservices, there are two approaches for software development. The first one is ‘Design First’ and the second is the ‘Code First’ approach.
- Design First: The plan is converted to a contract that is both human and machine-readable. For example, the code built from Swagger Document.
- Code First: APIs are directly coded based on business plans, from which a human or machine-readable document, such as Swagger Document generated.
Approach for Software Development: Monolithic vs Microservices
As hot a trend as it may seem and as advantages might seem strong enough to convince more and more enterprises to adopt the methodologies, but on the flip side, it does not come with its drawback. Let’s have a comparison between Monolithic and Microservice Architecture.
| Monolithic Architecture | Microservice Architecture |
| Architect an application as a single deployable unit | Architect an application as a collection of loosely coupled services |
| Focuses on entire project | Doesn’t focus on the entire project, rather focuses on a product or service |
| Follows single-tier application for all business goals | Each component of the entire application must be small and must deliver end-goals |
| All services are tightly coupled | All services work independently |
| Works well with the early stages of project | Works well in the late stages |
| Uses a single development stack for implementation. Also, it is difficult to adopt new technologies and make changes. | Different technologies and development can be used. |
| The whole system needs to be pulled down in case of any issue | Other components do not get affected if one service goes down |
| Software development processes generally result in large terms working on single monolithic deployment artefact | Services are encouraged to be small, usually owned by small terms |
| Difficult in case of continuous deployment | Independently deployable |
| Scaling monolithic application can be challenging | Services are independent of other services |
| In case of repeated deployment, operational agility is difficult to achieve | By Breaking down functionality to the most basic level, DevOps can focus on only updating the relevant features of an application |
| It is a simple testing process | The testing process can be cumbersome |
| Easier to start a new project with a monolithic architecture | Developing distributed systems can be complex and developers might get forced to write extra code to avoid distribution |
Everything you need to know about Monolithic Software
A monolithic application describes a single-tiered software application in which the user interface and data access code are combined into a single program from a single platform.
Monolithic Software uses three-tier architecture
- Presentation layer: is the topmost layer of the application and describes the user interface. Its main function is to translate tasks and results to something that users can understand
- Business layer: This layer makes logical decisions and performs calculations. It processes the data between two layers and uses technologies like Spring.
- Data access layer: From the database, information is stored and retrieved which is then passed to the business layer and then ultimately to the user.
This type of architecture worked well for some time, but due to the increased need for continuous delivery, multiple issues are there for each model.
Drawbacks of Monolithic Architecture
- Operational Overhead: Different stakeholders work with different layers of a monolithic application, hence, the team will be confined to specific domain expertise. The team who works on the presentation layer are specialized in UI technologies but has the least knowledge of the data access layer. Thus, if a new feature is to be added, it requires different teams to coordinate and deliver a particular feature. This results in more time span from ideation to time-to-market and ultimately affects the business ROI.
- Implicit Interface: As the codes are released in a single file, a minor change in the application calls for the rebuilding of the entire application. Because of this, ongoing applications are put down and resulting in the need of redeploying the new functions. This in turn results in fewer updates and is not able to evolve as fast as it should.
Monolithic applications have been in the traditional approach, but limitations in scaling, difficulties in maintaining a large codebase, and high-risk upgrades have compelled Software Development Company to explore different approaches. Monolithic applications are tough to crack and difficult to understand with time.
So, in order to avoid such problems, Microservice architecture can be a saviour.
All you need to know about Microservice Architecture
Microservices are the software development technique that structures an application as a collection of loosely based couple services. Microservice provides opportunities for adding resiliency to the systems so that components can handle spikes and errors gracefully. Moreover, communications in microservice can be carried out without any effort as they are stateless and in a well-defined interface.
Microservices and Containers- Docker, Kubernetes, etc
Containers are the underlying technology that has gone furthest towards getting microservices into the mainstream. A container is similar to a VM instance, but instead of including an entire self-contained operating system, a container is just an isolated user-space that makes use of the host operating system’s kernel but otherwise keeps the code executing inside of itself. Containers are comparatively easy to quickly deploy and are much smaller than VM instances, either locally or in the cloud, and can also be spun up and down to match demand and available resources. iTechnolabs is Software development Company that help you to create both large scale application while handling the bigdata using CI/CD pipelines methods.
The appeal of microservice is that each individual microservice can run in its own container, which cuts the overhead of managing services significantly. Most container implementations have complementary orchestration tools that automate the management, deployment, networking, scaling and availability of container-based applications. It is a combination of small easy-to-build microservices and easy-to-deploy containers that makes approaches for software development much easier and also makes DevOps philosophy possible. Several implementations of container concepts exist, but by far the most popular are Docker and Kubernetes as orchestration platforms.
Spring, while popular, is tied to the Java platform. On the other hand, container-based systems are polyglot, i.e. any programming language that supports the operating system can run in a container. This gives more flexibility to programmers and indeed is a significant advantage of microservice that each service can make the most sense to whatever language is written. A service could be completely rebuilt in a new language without affecting the system as a whole, as long as the APIs remain stable.
Design Pattern of Microservices
It doesn’t matter what language you use to develop microservices, developers will face issues which other developers might have encountered before. To define a design pattern, they are formalized and abstract solutions to recurring problems in computer science and a number of them are specifically for microservices, which includes:
- Service Registry: to connect clients for available instances of microservices
- Fallback: to provide an alternative to a failed service
- Circuit Breaker:for preventing failed services to being further repeated
- Sidecar: to provide an auxiliary service to the main container, for example, logging, monitoring or synchronizing services
- Ambassador: for connecting the main container to the outside world, for example, proxying local host connections to outside connections
- Adapter: to standardize or normalize the interface between the main container and the external world