Service-oriented architecture facts for kids
Service-oriented architecture (SOA) is a way to design and build computer programs. Instead of making one huge program, SOA breaks it down into smaller, independent parts called "services." Think of it like building with LEGOs. Each LEGO brick is a service, and you can combine them in different ways to create a bigger structure.
These services are like mini-programs that can do specific jobs. For example, one service might handle logging in, another might process payments, and another might show you your account balance. They can be used by other programs over a network, like the internet. This makes it easier for different computer systems to work together and share information.
A service has a few key features:
- It does a specific task with a clear result.
- It works on its own.
- It's like a "black box" – you don't need to know how it works inside, just what it does.
- It can be made up of other smaller services.
SOA helps different software parts, even if they are built by different companies or in different programming languages, to communicate and cooperate. It's a bit like how an API works, which is a set of rules for how different software parts talk to each other. SOA is the overall plan that lets these services operate smoothly.
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How Services Work
In SOA, services use special rules called "protocols" to send and understand messages. These rules also describe what the service does and how well it performs. The main goal of SOA is to let people combine many different services to create new applications.
Imagine you want to build a new app. With SOA, you can use existing services for things like user login, payment processing, or showing maps, instead of building them from scratch. Each service has a simple way to connect to it, hiding all the complicated stuff happening behind the scenes. This means users can access these services without knowing how they are built.
Key Ideas of SOA
A big idea in SOA is "loose coupling." This means that services are designed to be as independent as possible. If one service changes, it won't easily break other services that use it. This makes software more flexible and easier to update.
SOA lets developers create functions as separate units, or services. These services are then made available over a network. This allows users to combine and reuse them to build new applications. Services and the programs that use them communicate by sending data in a clear, shared format.
SOA is part of a bigger trend in computing. It connects older ideas like distributed computing (where parts of a program run on different computers) to newer ideas like cloud computing (where services are delivered over the internet).
Main Principles
There isn't one strict rulebook for SOA, but many experts agree on certain principles:
- Standard Rules: Services follow a common agreement on how they communicate.
- Independent Services: Services are designed to be very independent. They only need to know that other services exist, not how they work internally.
- Anywhere Access: Services can be called from anywhere on the network, no matter where they are physically located.
- Long-lasting: Services should be designed to work for a long time. If you use a service today, it should still work tomorrow.
- Hidden Details: Services act like "black boxes." Their internal workings are hidden from the programs that use them.
- Self-controlled: Services are independent and control their own functions.
- No Memory: Services usually don't remember past interactions. They just do their job and return a result. This helps save computer resources.
- Right Size: Services should be the right size and scope. They should do a meaningful amount of work for the user.
- Less Duplication: Services are designed to avoid repeating the same functions.
- Combineable: Services can be combined with other services to create new, more complex services.
- Easy to Find: Services come with information that helps other programs find and understand them.
- Reusable: The logic within services is designed so that it can be used again and again in different parts of a system.
- Wrap Around: Existing older systems can be "wrapped" or included into SOA, making them available as new services.
How Services Interact
In SOA, there are three main roles that parts of the system can play:
- Service Provider: This is the part that creates a service and makes its information available. The provider decides what services to offer, how secure they should be, and how much they might cost to use.
- Service Broker (or Registry): This is like a directory or a phone book for services. Its main job is to list information about available services so that others can find them.
- Service Requester (or Consumer): This is the part that looks for services in the broker's directory. Once it finds a service it needs, it connects to the service provider to use that service.
The relationship between the service consumer and provider is guided by a "standardized service contract." This contract describes what the service does, how to use it, and any technical details.
Services can also be combined in different ways, like in a dance. Sometimes one service leads (orchestration), and sometimes services work together more freely (choreography).
How SOA is Built
SOA can be built using different technologies. A common way is to use web services. These services are designed to be accessed over standard internet rules, no matter what kind of computer or programming language is used. Services can be brand new programs or just ways to make older systems available over the network.
Many SOA systems use web service standards like SOAP. These standards help different systems work together smoothly. However, SOA can also be built using other technologies like REST or gRPC.
The important thing is that services are independent, have clear ways to connect to them, and can be called upon to do their jobs without knowing how they are built inside. This allows developers to create applications by combining many independent services.
For example, a service written in one programming language (like C#) can be used by an application written in another language (like Java). This makes it easy to reuse code and connect different parts of a system.
Special programming languages and tools can also help combine smaller services into bigger "business services." These larger services can then be used in workflows and business processes.
Benefits for Businesses
Many experts believe that SOA can help businesses react faster and more affordably to changes in the market. This way of building software encourages reusing large parts of code (services) instead of small ones (like individual classes). It also makes it easier to connect to and use existing computer systems that a company already has.
With SOA, a business can look at its problems as a whole. Instead of many developers doing their own thing, they can all follow a standard way of building software set by the business. This helps create a company-wide system that supports business goals. It's like building a highway system for cars. If everyone has a car but no highways, things would be slow. SOA "builds highways" for data and services.
SOA is more of an evolution than a revolution in software design. It uses many good ideas from older ways of building software. For example, it's similar to component-based software engineering, where programs are built from reusable components.
Treating services as separate projects from larger ones has several benefits:
- It shows businesses that services can be delivered quickly and independently. This helps companies be more agile and bring new ideas to market faster.
- It encourages good design because services are built without knowing exactly who will use them.
- The instructions and tests for a service are kept separate, which is important when the service needs to be reused later.
SOA can also make testing easier. Because services are independent and have clear connections, they can be tested like "black boxes." This means you can test them without knowing their internal details.
Related Ideas
Application Programming Interfaces
APIs are like menus that show developers how they can interact with a web application. SOA uses APIs to define how its services communicate.
Web 2.0
Web 2.0 describes a set of web applications that are interactive and user-focused. Some people see Web 2.0 and SOA as similar because both involve hiding complexity and reusing parts. Others see them as different but complementary. By 2008, people were already combining ideas from both to create new applications.
Microservices
Microservices are a modern way to build software using ideas from SOA. They became very popular after 2014. In a microservice design, services are very small, independent programs that talk to each other over a network. They are often built by small teams and can be updated and deployed very quickly.
Key features of microservices include:
- Very small, independent services.
- Focus on business needs.
- Good for cloud applications.
- Teams can use different programming languages and databases for different services.
- Easy to deploy using lightweight containers.
- Focus on continuous delivery and DevOps (combining software development and operations).
See also
In Spanish: Arquitectura orientada a servicios para niños
- Application programming interface
- Loose coupling
- Software architecture
- Web Application Description Language
