MQTT vs REST from IoT Implementation perspective

Instant Response – The Need of the Hour

REST is a well-established architectural style that offers flexibility and scalability with relatively low maintenance costs. However, one of its major drawbacks is latency in request processing and increased bandwidth consumption. This is primarily because REST follows a one-way communication model where the connection between the client and server is intermittent.

In REST-based communication, a client initiates a connection to send data to the server and retrieves data from the server only when required. This intermittent connection model results in delays, as the server has to wait for the client to connect before sending the intended data. To avoid excessive load on the server, most IoT solution providers configure edge devices or gateways to connect at intervals of one minute or longer. While this strategy optimizes server performance, it introduces delays that may not be acceptable for real-time applications.

For instance, consider a scenario where a user activates a light using a mobile app. The request from the mobile device reaches the server almost instantly. However, the server must wait for the client device to initiate a connection before it can relay the command, causing a noticeable delay.

On the other hand, MQTT enables persistent client-server connectivity, ensuring two-way communication in real time. This always-connected architecture allows the server to push messages instantly to edge devices, ensuring an immediate response to user commands.

Furthermore, MQTT is designed to optimize power consumption. When transferring the same data, MQTT consumes approximately 20% less power than REST. This efficiency is particularly important for battery-operated remote devices, where frequent connection and disconnection processes in REST-based communication lead to unnecessary energy loss. By minimizing resource-intensive operations, MQTT extends battery life and enhances overall device efficiency.

Ensuring Secure IoT Deployments

Security is a top priority in IoT deployments, with most devices operating behind firewalls to prevent unauthorized access. One of the key challenges of REST is its inability to facilitate direct server-to-client communication on demand. Even if a REST server is deployed on the client device, initiating a connection from the server is often impossible when devices are protected by firewalls.

MQTT inherently addresses this issue with its persistent connection model. Since MQTT clients maintain an active connection with the broker, real-time, bidirectional communication remains uninterrupted. This capability makes MQTT the preferred choice for applications requiring instant data exchange between servers and client devices, regardless of their network environment.

MQTT vs REST: Performance Comparison

The fundamental difference between MQTT and REST is their connection model. While REST relies on intermittent connections, MQTT maintains a persistent link between the client and the server. This architectural difference has a profound impact on performance and scalability.

In REST-based communication, establishing and terminating a connection for each data exchange introduces significant overhead. Each reconnection requires authentication, session initialization, and resource allocation, leading to increased latency. By contrast, MQTT's keep-alive mechanism ensures continuous connectivity with minimal overhead, resulting in superior performance.

Studies and test results indicate that MQTT can transfer data 20 to 25 times faster than REST. The number of transactions a system can handle depends on the concurrent connections the server can manage within a given timeframe. Modern web servers can typically handle thousands of simultaneous connections, limiting the number of REST transactions that can be processed sequentially. In contrast, an MQTT broker running on a commodity server can handle up to 40,000 messages per second, with support for as many as 50,000 parallel connections. By adjusting hardware specifications, MQTT can further enhance scalability and accommodate large-scale IoT deployments.

Enhanced Performance & Lightweight Nature of MQTT over HTTP

One of the key reasons MQTT outperforms REST over HTTP in IoT implementations is its lightweight protocol design. MQTT uses a binary message format with minimal overhead, making it far more efficient for low-bandwidth and resource-constrained environments. Unlike HTTP, which requires larger headers and repeated handshakes for each request, MQTT maintains a persistent connection, significantly reducing data exchange overhead. This makes MQTT protocol particularly well-suited for IoT devices with limited processing power and memory. Additionally, MQTT’s efficient packet structure ensures faster message transmission, even over unreliable networks, making it the preferred choice for real-time IoT communication.

Error Handling, Flexibility, and Scalability

Another key advantage of MQTT is its robust error-handling mechanism. Unlike REST, where error messages are often generic and lack detailed diagnostic information, MQTT provides precise error descriptions that enable efficient troubleshooting. With MQTT 5, error handling has been further enhanced, allowing for improved diagnostics and transparency in identifying the root cause of connectivity issues.

Moreover, MQTT 5 introduces advanced load balancing and optimized message processing capabilities, making it an ideal protocol for large-scale industrial applications. Its ability to support flexible topic structures, hierarchical message distribution, and Quality of Service (QoS) levels ensures seamless scalability and adaptability to diverse IoT scenarios.

MQTT vs REST: A Side-by-Side Analysis

Why MQTT is the Superior Choice for IoT?

When evaluating MQTT vs REST for IoT implementations, MQTT emerges as the clear winner due to its real-time responsiveness, lower power consumption, superior scalability, and robust error-handling capabilities. While REST remains a viable option for certain applications, it falls short in meeting the demands of large-scale, high-frequency IoT deployments.

To learn more about MQTT and how to develop MQTT clients, refer to our MQTT Client development guide. Additionally, Bevywise MQTT Broker offers a robust and high-performance solution for secure and scalable IoT connectivity.

Our MQTT broker supports an extensive set of REST APIs, allowing seamless integration with external applications. Explore our MQTT Broker API documentation to discover how REST API calls can be used to control and manage edge devices efficiently.

Experience the benefits of MQTT firsthand by trying our MQTT Broker for FREE and achieve seamless, real-time IoT connectivity.