Choosing the Best Messaging System: Practical Guide
Tags: webdev, messaging, microservices, beginners
Published: 2024-05-27 18:16:34

When it comes to communication between microservices, choosing the right messaging system is crucial. These systems guarantee the independence of services by storing events in a broker to be consumed when the services are available. However, with a variety of options on the market, such as Kafka, RabbitMQ and SQS, how do you decide which one to use? In this article, we'll explore the basics of queuing and the key differences between some of the major players.

## **Message Ordering**

It is important to understand how messages are ordered in queuing systems. The most common methods are FIFO (First In, First Out) and LIFO (Last In, First Out). Additionally, some brokers offer priority queues, allowing important messages to be consumed first, regardless of the default order.

## **Types of Queues: Pull vs. Push**

Another crucial aspect is the type of queue: Pull or Push. In a push queue, messages are automatically sent to consumers regardless of their status. This can lead to problems if consumers cannot process the volume of incoming messages. On the other hand, in a pull queue, consumers request new messages from the broker, ensuring that they can process them correctly, although this may be slower.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/oqeyjnt4reszbcvqqct3.png)

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ew5x9esqjl291v4v8ny1.png)

## **Difference between Messaging and Stream**

Messaging enables asynchronous and reliable communication between systems, useful when message order is not critical and data does not need to be delivered in real time. On the other hand, streaming services deal with continuous streams of data in real time, maintaining the order of records. This is ideal for processing large volumes of data in real time where order is crucial.

### **Amazon SNS (simple notification service)**

**Advantages:** Self-managed service that supports sending messages to multiple destinations, integrated with AWS services, facilitating the construction of cloud-based applications.

**Disadvantages:** May be more expensive for applications with high message load and may not offer granular control over message consistency.

### **Amazon SQS (simple queue service)**

**Advantages:** Managed and fault-tolerant queuing service, with automatic replication of messages between clusters.

**Disadvantages:** Message size limit and possibility of receiving duplicate messages due to replication.

### **Redis**

**Advantages:** Simple configuration and quick access to data due to its memory storage.

**Disadvantages:** Lack of guarantees on message delivery order and latency for larger messages.

### **RabbitMQ**

**Advantages:** Granular control over message consistency, support for multiple protocols and messaging models such as pub/sub and FIFO ordering.

**Disadvantages:** Complex configuration for scalability beyond a high rate of requests per second.

### **Apache Kafka**

**Advantages:** Highly scalable, fault tolerant and suitable for handling large volumes of data in real time.

**Disadvantages:** Complexity in configuration and lack of integrated tools for management and monitoring.

## **Conclusion**

Choosing the right messaging system depends on the specific needs of your project. Consider factors such as scalability, consistency, cost, and configuration complexity when making your decision. Carefully evaluate each option and choose the one that best meets your system requirements.