Overview
This project is intended to be a suitable test tool for testing MQTT brokers. It uses fusesource mqtt-client library and its command line interface for MQTT clients - publishers and subscribers. This project adds the ability to run huge amount of simultaneously connected clients publishing messages to a broker. This simulates the real load on the broker.
Usage
Download executable jar file and run the clients from command line.
Run this command for getting help: java -cp mqtt mqtt-test-suite-0.1-SNAPSHOT-jar-with-dependencies.jar com.tado.mqtt.suite.cli.Publishers
Publishers
Publishers give the ability to publish one or more messages with one or more mqtt clients to the broker. It allows to specify different MQTT variables like retain message, QoS, etc. (see the help running the command without any parameters). Concurrent publishers allow to publish messages by multiple clients. During the whole test all created MQTT (TCP/IP) connections are hold - they are closed in the end of the test.
Example:
java -cp mqtt-test-suite-0.1-SNAPSHOT-jar-with-dependencies.jar com.tado.mqtt.suite.cli.Publishers
-h "tcp://localhost:61613" -t "test/topic" -m "Test message" --client-count 5000
--msg-count 1 -pc --will-topic "dead/topic" --will-payload "I am dead, sorry"
Subscriber
The subscriber is capable to subscribe for certain topic.
Example:
java -cp mqtt-test-suite-0.1-SNAPSHOT-jar-with-dependencies.jar com.tado.mqtt.suite.cli.Listener
-h "tcp://localhost:61613" -t "test/topic"
Enhancements
In order to be able to create huge amount of simultaneously connected clients on one machine, you need to adjust os variables which restrict the maximum opened socket connections per process. Also, we need to give more memory to the java process which is going to maintain all these clients.
Increase Maximal Opened Connections
Each system has its own specific ways how to increase number of opened files. You can read an interesting article how to set this number in OS X, however it could be a good starting point for all unix systems.
Increase Heap Space
To increase the memory used by the java process we need to set the heap space size:
java -Xmx1024m -cp mqtt-tes...
TODO
- Enable the user to choose if he wants to close the MQTT (TCP/IP) connection after a client task is executed.