MQTT Broker Testing · Page 2

How to test an MQTT broker: connectivity, QoS, TLS, authentication, latency and load tests with ready-to-run scripts, CLI tools and checklists.

Broker Testing

MQTT Integration Testing: Test Your App Against a Real Broker

Write reliable MQTT integration tests with pytest and Jest against a real broker: unique topic prefixes, waiting for SUBACK, cleanup and no flaky sleeps.

10 min read

Broker Testing

Testing MQTT.js Code with Jest and Vitest

Unit and integration tests for MQTT.js 5 apps with Jest or Vitest: fake clients, a waitForMessage helper with timeouts, real-broker tests and clean teardown.

9 min read

Broker Testing

MQTT Load Testing with JMeter: Plugin Setup, Thread Groups and Results

Load test an MQTT broker with Apache JMeter: install the MQTT plugin, build publisher and subscriber thread groups, run headless and read the results.

9 min read

Broker Testing

MQTT Integration Tests in Java with JUnit 5

Write reliable MQTT integration tests in Java with JUnit 5: Eclipse Paho and HiveMQ client examples, Awaitility assertions and Testcontainers brokers.

9 min read

Broker Testing

MQTT Load Testing with k6 and xk6-mqtt

Load test an MQTT broker with k6 and the xk6-mqtt extension: install or build k6, write publisher and subscriber scripts, measure latency and set thresholds.

9 min read

Broker Testing

Testing Large MQTT Payloads and Maximum Message Size

What is the maximum MQTT message size? Learn the 256 MB protocol limit, broker limits like message_size_limit, MQTT 5 Maximum Packet Size and how to test.

9 min read

Broker Testing

MQTT Latency Test: Measure Round-Trip Time Correctly

How to run an MQTT latency test: measure publish-to-receive round-trip time with one clock, avoid NTP pitfalls, report p50/p99 and compare broker regions.

8 min read

Broker Testing

MQTT Load Testing with Locust

Load test an MQTT broker with Locust: a paho-mqtt 2.x User class reporting connect and PUBACK times, end-to-end latency, live dashboards and distributed runs.

10 min read

Broker Testing

Testing MQTT 5 Message Expiry Interval

How to verify MQTT 5 Message Expiry Interval: test queued messages for offline clients, retained message expiry and the remaining interval with CLI and Python.

8 min read

Broker Testing

Does MQTT Guarantee Message Order? Test It Yourself

What MQTT really guarantees about message order per topic and QoS, where ordering breaks, and Python scripts that detect out-of-order and duplicate messages.

8 min read

Broker Testing

Mocking MQTT in Unit Tests: Fakes, Stubs and In-Memory Brokers

How to mock MQTT in unit tests: unittest.mock for paho-mqtt, Jest mocks for MQTT.js, an in-memory fake, aedes as an embedded broker, and where unit tests end.

9 min read

Broker Testing

MQTT Client Performance Tuning: Inflight, Batching and Buffers

Speed up MQTT publishers and subscribers: tune max inflight, publish asynchronously, batch payloads, size queues and keep-alive, and fix Nagle delays.

9 min read

Broker Testing

How to Test MQTT with Postman

Use Postman's MQTT request to connect to a broker, subscribe to topics and publish messages — plus its limitations and when another MQTT test tool is better.

7 min read

Broker Testing

Monitor MQTT with Prometheus and Grafana

Monitor an MQTT broker with Prometheus and Grafana: mosquitto-exporter, EMQX metrics, a Python probe exporter, a Docker Compose stack, dashboards and alerts.

9 min read

Broker Testing

pytest Fixtures for MQTT: Clean, Fast, Isolated Tests

Reusable pytest fixtures for MQTT with paho-mqtt 2.x: connected clients with automatic cleanup, unique topics per test and message collectors with timeouts.

9 min read

Broker Testing

Testing MQTT Reconnect Logic and Backoff

How to test MQTT reconnect logic: simulate broker restarts and silent network drops, verify exponential backoff, resubscription and persistent session resume.

9 min read

Broker Testing

Record and Replay MQTT Traffic for Testing

Capture live MQTT traffic to a JSONL file and replay it with the original timing to build realistic regression tests. Python scripts, pitfalls and checks.

8 min read

Broker Testing

Testing MQTT 5 Request/Response with Response Topic and Correlation Data

Build and test MQTT 5 request/response: Response Topic, Correlation Data, mosquitto_rr, Python and MQTT.js examples, plus timeouts and concurrency tests.

9 min read

Broker Testing

Testing Session Expiry and Offline Message Queues

How to test MQTT persistent sessions: verify Session Present, offline message queues, Session Expiry Interval and queue limits with mosquitto_sub and Python.

9 min read

Broker Testing

Testing MQTT Shared Subscriptions and Load Balancing

How to test MQTT shared subscriptions: check broker support, verify message distribution across $share group members and test failover when a worker crashes.

9 min read

Broker Testing

A One-Minute MQTT Smoke Test Script (Bash, Python, Node)

Copy-paste MQTT smoke test scripts in Bash, Python and Node.js that connect, subscribe, publish and receive, then print PASS or FAIL with a CI-ready exit code.

8 min read

Broker Testing

MQTT Soak Testing: Find Memory Leaks and Slow Degradation

How to run a 24–72 hour MQTT soak test: a Python harness that logs gaps, latency and memory, broker metrics to watch, and how to spot leaks in the data.

9 min read

Broker Testing

Monitor an MQTT Broker with $SYS Topics

Use MQTT $SYS topics to monitor a broker: what Mosquitto and EMQX publish, how to subscribe to $SYS/#, turn counters into rates and graph them in Python.

8 min read

Broker Testing

Capture MQTT Traffic with tcpdump

tcpdump recipes for MQTT on servers, containers and gateways: port and packet-type filters, rotating captures, spotting disconnects and analysing pcap files.

8 min read