Application of Message Queue in Distributed Data Processing and Load Balancing

Problem

In the past, when we were in school, did anyone wonder why we had to study data structures and algorithms? The subject teaches us some common data structures such as linked lists, arrays, queues, stacks... But it seems boring for those who already know and are programming. Not to mention that most programming languages ​​implement or have libraries that support all these structures, yet teachers still require us to manually implement these structures.

Perhaps the real purpose behind that is to make us understand the importance of data structures. Indeed, many ideas and solutions are invented based on them. One can mention Message queue - a structure that appears in the design of software systems, aiming to increase the processing capacity and solve many complex problems in distributed systems.

In recent years, the concept of distributed systems is no longer unfamiliar. Instead of processing everything in one place, the work is divided into smaller tasks for processing. Each place handles a single task, thereby making the hierarchical system clearer, more productive, and more error-tolerant.

Queue is a waiting line, and a message queue is a message queue. A queue operates on the principle of First In, First Out (FIFO). Imagine you have a wide pipe to put marbles in, then pour all the marbles into the funnel at one end, the other end still rolls out one by one in order. It is impossible for two marbles to roll out at the same time, that is a queue.

In software systems, message queue is an important and widely applied structure in distributed systems. Therefore, in today's article, let's go through some basic concepts about this structure.

What is a Message Queue?

Message queue is a concept in the field of distributed systems and multithreaded programming. It is a data structure used to store messages in a distributed system.

Message queues are often used to communicate between components of an information system, allowing them to send messages to each other asynchronously. Instead of sending messages directly from one component to another, these components send messages to the message queue, and other components can retrieve messages from the message queue for processing.

Why not send messages directly but through a message queue? There are many reasons, among which the most notable is to manage messages. Imagine if you send a message directly to an unavailable destination, what would happen? The message may be lost and the system will never process the message again.

How does a Message Queue work?

Basically, a message queue is a message waiting line. In addition, to put messages into the queue and process them, there must be the participation of many components. The combination of them forms a complete message queue processing system.

Depending on the message queue service provider, there may be different components. But basically, there must be at least 3 components involved in the process: Producer, Message queue, and Consumer.

The Producer (message sender) sends messages to the message queue: The Producer is the component or application that creates messages and sends them to the message queue. Messages can be any type of data, such as messages, processing tasks, events, or requests.

The Message queue is where messages are stored: The message queue stores messages sent by the Producer. Messages can be stored persistently in memory or on disk depending on the configuration of the message queue.

The Consumer (message receiver) retrieves messages from the message queue: The Consumer is the component or application that wants to receive and process messages. The Consumer requests to retrieve messages from the message queue, and after receiving the message, the Consumer processes it according to the logic of the application.

This process repeats each time the Producer sends more messages to the Message queue and the Consumer retrieves and processes the messages. The asynchronous nature between the Producer and Consumer allows the system to operate efficiently and flexibly, while ensuring reliability and scalability.

How is Message Queue applied?

Message queues have many applications in distributed systems and multithreaded programming, such as:

• Real-time data processing systems: In real-time data processing systems, message queues are used to transmit data from various sources to processing systems. Data sources send messages to the message queue, and processing systems retrieve messages from the queue to process data in parallel and asynchronously.

• Multithreaded and asynchronous systems: Message queues allow components in a system to operate independently and asynchronously. Components can send messages to the message queue and continue their work without waiting for responses from other components. This helps improve the performance and scalability of the system.

• Event processing systems: In event processing systems, message queues are used to send and receive events from various sources.

• Communication between services: In distributed service architecture, message queues are used to communicate between services. Services send messages to the message queue to request or transmit information to other services.

• Task queue systems: Message queues are also used in task queue systems, where tasks are sent to the message queue and then processed sequentially.

These are just some typical examples of using message queues. In reality, message queues can be applied in many different fields and situations, depending on the requirements and purposes of the system.