What is middleware?

Middleware is software that different applications use to communicate with each other. It provides functionality to connect applications intelligently and efficiently so that you can innovate faster. Middleware acts as a bridge between diverse technologies, tools, and databases so that you can integrate them seamlessly into a single system. The single system then provides a unified service to its users. For example, a Windows frontend application sends and receives data from a Linux backend server, but the application users are unaware of the difference.

Why is middleware important?

Middleware started as a bridge between new applications and legacy systems before it gained popularity in the 1980s. Developers initially used it to integrate new programs with earlier systems without rewriting the earlier code. Middleware has become an important communication and data management tool in distributed systems.

Developers use middleware to support application development and simplify design processes. This leaves them free to focus on business logic and features instead of connectivity between different software components. Without middleware, developers would have to build a data exchange module for each software component that connects to the application. This is challenging because modern applications consist of multiple microservices or small software components that talk to each other. 

What are the use cases of middleware?

The following are the more common use cases of middleware:

Game development

Game developers use middleware as a game engine. For a game to work, the software must communicate with various image, audio, and video servers along with communication systems. The game engine facilitates this communication and makes game development more efficient.

Electronics

Electronics engineers use middleware to integrate various types of sensors with their controllers. The middleware layer allows sensors to communicate with the controller through a common messaging framework. 

Software development

Software developers use middleware to integrate different software components into other applications. Middleware offers a standard Application Programming Interface (API) to manage the required input and output of data from the component. The internal linking with the component is hidden from the user. Developers use the APIs to request the services that they need from the software components. 

Data transmission

Software applications use middleware to send and receive data streams reliably. Data streams are a high-speed transmission of continuous data. They are important for reliable video and audio streaming.

Distributed applications

Distributed applications are software programs that run on different computers on a network. They usually consist of frontend and backend applications. Frontend applications are software you use on a computer or mobile device, such as a social media app. By contrast, backend applications are software programs that handle data processing, business logic, and resource management tasks. Middleware communicates between the frontend and backend applications, so the distributed application works smoothly.

What is middleware architecture?

Middleware software architecture consists of several components that communicate to create a data pipeline. The data moves from one connecting application to the other through the middleware. The middleware processes the data for compatibility. The following are common components of middleware software:

Management console

The management console provides software developers with an overview of the middleware system's activities, software rules, and configurations.

Client interface

The client interface is the outer part of the middleware software that communicates with the applications. Developers use functions provided by the client interface to interact with other applications, databases, or other microservices.

Middleware internal interface

The middleware internal interface acts as the software glue that binds the various components together. The middleware components use the internal interface to function cohesively with their own protocol. 

Platform interface

The middleware interface ensures that the middleware program is compatible with various platforms. It contains software components that work with different types of operating systems. 

Contract manager

The contract manager defines the rules for data exchange in the middleware system. It also ensures that applications abide by the rules when sending data with the middleware. It sends an alert, or an exception, to the application when it breaches specific rules. For example, the contract manager will return an exception if the application sends a number when a word is expected. 

Session manager

The session manager sets up a secure communication channel between applications and the middleware. It ensures that communication flows seamlessly and stores data activity records for reporting. 

Database manager

Some types of middleware also include a database manager. The database manager is responsible for integrating with different database types, as required. 

Runtime monitor

The runtime monitor provides continuous monitoring of data movements in the middleware. It detects and reports unusual activities to developers. 

How does middleware work?

Middleware abstracts the underlying communication process between components. This means that the frontend application communicates only to the middleware and does not have to learn the language of other backend software components. 

Messaging framework

A messaging framework facilitates the exchange of data between frontend and backend applications. Common frameworks include the following:

  • JavaScript Object Notation (JSON)
  • Representational State Transfer (REST API)
  • Extensible Markup Language (XML)
  • Web services
  • Simple Object Access Protocol (SOAP) 

The messaging frameworks provide a common communication interface for applications in different operating platforms and languages. Applications write and read data in a standardized format provided by the messaging framework. 

Example of middleware

For example, a web server is middleware that connects websites to the backend database. When you submit a form on a website, your computer sends the request in XML or JSON to the web server. Then, the web server runs the business logic based on the request, retrieves information from databases, or communicates to other microservices using different protocols.

Other middleware functions

Besides being an intermediary between software applications, middleware programs also do the following:

  • Provide a secure communication channel between distributed applications so that websites send sensitive information safely to backend applications. 
  • Manage traffic flow and avoid overwhelming a particular application or file server.
  • Automate and customize responses to the request. For example, the middleware sorts and filters the results before sending them to the frontend application.

What is platform middleware?

Platform middleware supports application development by providing a system of managed tools and resources. Developers use platform middleware to share or transfer resources between applications. following are some examples of platform middleware resources:

Runtime environments

A runtime environment is like a small operating system that allows a software program to run. For example, Java applications must run in the Java Runtime Environment. Developers can use AWS Lambda to set up a runtime environment for any programming language. 

Web servers

A web server is a computer program that receives, processes, and responds to requests from websites. Web developers use Amazon Lightsail to host and manage web servers for simple applications. 

Content management systems

The content management system is software that creates, modifies, stores, and publishes digital information. For example, WordPress is an open-source content management system for building websites. 

Containers

A container is a ready-to-deploy bundle of the application codes and necessary resources. Developers use Amazon Elastic Container Service (Amazon ECS) to deploy, manage, and scale containerized applications. 

What are the types of middleware?

Developers use middleware for various purposes in software development. The following are common types of middleware:

Enterprise application integration middleware

Enterprise application integration middleware connects all software systems, services, and data sources within an organization. Enterprise applications use this middleware to send information to each other without changing the network or database configurations. 

Database-oriented middleware

Data-oriented or database-oriented middleware facilitates the transfer of data between applications and different types of databases.

Message-oriented middleware

Message-oriented middleware (MOM) can support communication between the software components on a distributed computing system.

Transactional middleware

Transactional middleware, such as transaction process monitors, ensures that each step in a software transaction process is performed correctly. 

Content-centric middleware

Applications use content-centric middleware to publish or retrieve content without building the underlying storage mechanism.

Remote procedure call middleware

A software program uses remote procedure call (RPC) middleware to use the service of another program within the same network.

Device middleware

Device middleware provides the necessary resources for developers to build mobile applications on specific mobile devices, such as connectivity frameworks and libraries. 

Object request middleware

Applications use an object request broker or object request middleware to send requests without knowing where the target application is hosted.

Application server middleware

Developers use application server middleware to build, deploy, manage, and connect enterprise applications to the backend application servers.

Embedded middleware

Embedded middleware acts as a bridge between applications and the operating system in embedded systems. Embedded systems are electronics products that work with a microcontroller. 

API management middleware

Developers use API management middleware to create APIs and facilitate their use by other developers. 

Asynchronous data streaming middleware

Asynchronous data streaming middleware supports real-time data streaming among distributed systems.

Robotic middleware

Engineers use robotic middleware to integrate different types of robots regardless of their hardware, firmware, and manufacturer. 

What is middleware in cloud computing?

Cloud computing involves building and deploying cloud-native applications across different infrastructures. Developers use middleware to access cloud resources without being overwhelmed by the complexity of managing the infrastructures. Developers deploy cloud applications in containers on a scalable cloud-based hosting such as Amazon Elastic Compute Cloud (Amazon EC2).

Introduction to Amazon EC2

How does AWS support middleware technology?

Application Integration on AWS is a suite of services that are an affordable alternative to conventional middleware for cloud computing. Developers use the services to communicate between decoupled components within microservices, distributed systems, and serverless applications. For example:

  • AWS Step Functions is a visual workflow service that allows developers to build distributed applications, automate IT and business processes, and build data and machine learning pipelines by using AWS services.
  • Amazon Simple Notification Service (Amazon SNS) is an alternative to message-oriented middleware. It provides messaging services for applications.
  • Amazon EventBridge is a serverless event bus that developers use to integrate cloud applications with AWS services.  

Get started with middleware on AWS by creating an AWS account today.

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