MQTT Broker Testing · Page 3

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

Testing MQTT on Slow and Flaky Cellular Networks

Emulate 2G, 3G and LTE latency, jitter and packet loss with tc netem, then tune MQTT keep-alive, payload size, QoS and sessions for mobile IoT devices.

9 min read

Broker Testing

MQTT Broker Test Checklist: 25 Checks Before Production

A pre-production MQTT broker test checklist: 25 checks for connectivity, TLS, authentication, ACLs, QoS, retained messages, resilience and load, with commands.

10 min read

Broker Testing

Generate Realistic MQTT Test Data (Sensors, JSON, Binary)

Generate realistic MQTT test data: Python and Node.js scripts for sensor telemetry with daily cycles, noise and drift, encoded as JSON or compact binary.

9 min read

Broker Testing

Setting Up MQTT Dev, Staging and Production Environments

How to separate MQTT dev, staging and production: brokers per environment, topic prefixes, credentials and ACLs per env, config promotion and smoke tests.

8 min read

Broker Testing

Naming Test Topics So Tests Never Collide

Stop MQTT tests from colliding: unique topic prefixes per run, CI run IDs, narrow wildcards, unique client IDs and cleanup of retained test messages.

8 min read

Broker Testing

Simulating Bad Networks for MQTT with Toxiproxy

Use Toxiproxy to inject latency, bandwidth limits, timeouts and connection resets between your MQTT client and broker, and test keep-alive and reconnect logic.

9 min read

Broker Testing

MQTT Tests with Testcontainers (Java, Python, Node)

Start a throwaway Mosquitto broker for every test run with Testcontainers in Java, Python and Node.js, and learn when a hosted test broker is the better choice.

9 min read

Broker Testing

Testing MQTT in CI with GitHub Actions

Run MQTT tests in GitHub Actions: start a Mosquitto container that actually accepts connections, then test against a hosted broker using repository secrets.

9 min read

Broker Testing

MQTT Throughput Test: Messages per Second Explained

How to run an MQTT throughput test: ingress vs egress msg/s, finding the sustainable rate, spotting backpressure and turning msg/s into bandwidth.

9 min read

Broker Testing

Testing MQTT 5 Topic Aliases

How to test MQTT 5 topic aliases: read Topic Alias Maximum, verify aliased publishes, measure bandwidth savings and reproduce Topic Alias invalid errors.

8 min read

Broker Testing

External MQTT Uptime Monitoring and Alerting

Monitor MQTT broker uptime from outside: a synthetic publish/subscribe probe, cert expiry checks, cron and heartbeats, Slack and PagerDuty alerts, and SLO math.

9 min read

Broker Testing

Debugging MQTT with Wireshark: Read Every Packet

Capture and decode MQTT traffic in Wireshark: display filters for CONNECT, PUBLISH and CONNACK, decrypting TLS on port 8883 with a key log, and tshark recipes.

9 min read

Broker Testing

MQTTX Tutorial: Test Brokers with the Desktop and CLI Client

Learn MQTTX step by step: create connections, test MQTT 5 properties, script payloads, and use the mqttx CLI for pub/sub, simulations and bench load tests.

9 min read

Broker Testing

How to Test MQTT ACLs and Topic Permissions

Verify MQTT ACLs topic by topic: why a denied publish is silent in MQTT 3.1.1, the 0x87 reason code in MQTT 5, SUBACK 0x80, and an automated permission test.

9 min read

Broker Testing

Testing MQTT Authentication: Valid, Invalid and Missing Credentials

A test matrix for MQTT username/password auth: the CONNACK code each case should return in MQTT 3.1.1 and 5, mosquitto commands and an automated pytest suite.

8 min read

Broker Testing

Test an MQTT Broker from Android and iOS

How to test an MQTT broker from an Android or iOS phone: browser client over WSS, mobile MQTT apps, Termux, emulators, and the network traps unique to mobile.

7 min read

Broker Testing

Test an MQTT Broker from Your Browser (No Install)

Test any MQTT broker from your browser in two minutes: connect over secure WebSockets, subscribe, publish, check retained and Last Will, share test topics.

7 min read

Broker Testing

Diagnose MQTT Network Issues: DNS, Firewalls and Proxies

Find out why an MQTT client cannot reach the broker: test DNS, TCP routing, firewalls, corporate proxies and TLS interception layer by layer with real commands.

9 min read

Broker Testing

Testing MQTT Last Will: Simulate Ungraceful Disconnects

Test MQTT Last Will by simulating crashes with kill -9, frozen processes and network cuts, measure when the will fires and verify the MQTT 5 will delay.

9 min read

Broker Testing

How to Check if an MQTT Port Is Open (nc, telnet, nmap)

Check whether MQTT ports 1883, 8883, 8083 or 8084 are open with nc, telnet, nmap and PowerShell Test-NetConnection, and tell firewall problems from broker ones.

7 min read

Broker Testing

How to Test QoS 1 and QoS 2 Delivery Guarantees

Prove MQTT at-least-once and exactly-once delivery: kill connections mid-flight, count duplicates and gaps with sequence numbers, and inspect PUBACK and PUBREC.

9 min read

Broker Testing

How to Test Retained Messages (and Clear Them)

Test MQTT retained messages step by step: delivery on subscribe, overwrite, clearing with an empty payload and MQTT 5 retain options, with mosquitto and pytest.

8 min read

Broker Testing

How to Test an MQTT TLS Connection (openssl, mosquitto, code)

Test MQTT over TLS on port 8883: openssl s_client checks, certificate chain, SNI and hostname verification, mosquitto --cafile and fixes for common errors.

9 min read

Broker Testing

How to Test MQTT over WebSockets (ws and wss)

Test an MQTT WebSocket endpoint step by step: the /mqtt path, the mqtt subprotocol, curl and wscat handshake checks, browser DevTools and an MQTT.js test.

8 min read