[For Beginners] What is Middleware? A Thorough Explanation of Types, Roles, and Functions!

Hello.
I'm Kita from Beyond, and I've recently started playing the popular Pokémon TCG game.

Last time,post about how servers start upI wrote a blog
This time, I'd like to explain what middleware is in an easy-to-understand way.

This may not be a term you hear often in your daily life, but middleware is actually an essential part for systems to function

This time, we will explain the functions and types of middleware, including illustrations, so that even beginners can understand, so please read to the end

What is Middleware?

First, to put it simply, middleware isintermediate software what is known as

As the name suggests, middleware acts as a bridge between the OS (operating system) and applications.
There are many types of middleware, each specializing in specific functions and assisting both the OS and applications.

Let's review some terminology here

What is an OS?

OS stands for Operating System, and its role is to control the most basic functions of a computer.
In other words, it can only provide basic functions, and advanced features cannot be provided by the OS alone.

What is an application?

An application is also known as application software.
It's separate from the operating system and refers to software that enables various applied tasks.

Examples include Microsoft's spreadsheet software Excel and word processing software Word

To elaborate further on infrastructure operations,
is offered by Beyond reservation management systems like EDISONE, which .

Specific roles of middleware

Now, let's take a deeper look at the reservation system we mentioned earlier

When you think of a reservation system, you probably think of a service used to reserve conference rooms or stores, but that doesn't mean that this can be created using just an OS

When you decide to create a reservation system, the first thing you need is an application that provides the reservation function.
In other words, it's the program code written by the developer.

However, a reservation system cannot be created with just an application (code); it also needs features such as the ability to display the management screen and reservation information in a browser, the ability to save and manage data at the time of reservation, and the ability to send emails when a reservation is made

When we break down the reservation system in this way, we realize that multiple functions are required.
These multiple functionsmiddleware specialized for each purposeare implemented on the premise that

The specific functions are as follows:

Web Page = Apache

Store/manage data = Database/MySQL

Ability to send email = Postfix

As such, middleware that fulfills each role is required

Representative middleware

The diagram above shows typical types of middleware.
A commonly used configuration is Linux (OS) + Apache (Web page) + MySQL (database) + PHP (programming language), which is abbreviated LAMP , and servers are often built with this configuration.

the most widely used web server is said to be
*Currently, it seems to be competing with NGINX, which will be discussed later, for the No. 1 spot.

This middleware is widely used for everything from large-scale commercial sites to hobbyist servers built at home

There is a lot of information available online, and it is often used as a starting point for building a server

②NGINX

the same role as Apache web server and is used all over the world.
It is more feature-rich than Apache, and has functions such as reverse proxying, load balancing, and caching of HTTP requests.

③MySQL

a relational database management system (RDBMS),It is middleware called
as the name suggests, its role is to store and manage databases.

This is also the most widely used RDBMS in the world.
Furthermore, PostgreSQL, a middleware that serves the same purpose as a database, is often used as well.

⑤Dovecot

This is similar to Postfix in its function, but
using IMAP/POP3receive emailsit is middleware that has the functionality to

To put it simply,Postfix is ​​for sending emails and Dovecot is for receiving emails it's easiest to remember that

Overall view

Finally, we will use diagrams to explain and review the concepts

The process can be roughly summarized as follows:

1. Receives a web page request from the user (Apache)
2. The application program runs (PHP)
3. The program collates data from reservation management data (MySQL)
4. Returning a web page request (Apache)
5. Send a reservation completion email (Postfix)

The process goes something like this

lastly

So far, we have provided a detailed explanation of what middleware is, its functions, types, etc

There are many different types of middleware, each specializing in specific functions for different purposes.
Behind the scenes of the various systems we use every day, middleware acts as an intermediary software, helping us out. Thank you, middleware!

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