node-red-contrib-limit-message-rate-topic

Limit the rate of msg with a specific topic to the set period. If a message with a specific topic is received, it is sent out immediately. The next msg with the same topic will be sent only after the configured period has passed. Messages with the same topic received in the configured time period are discarded.

Installation

cd ~/.node-red
npm install <path-to-module>/node-red-contrib-limit-message-rate-topic

or install through the Palette menu.

Message options

All Option are optional.

• msg.topic (string): The topic of the message (can be empty).

• msg.stopTimer (boolean): If set to true, the timer for msg.topic is stopped and the message is discarded.

• msg.period (integer): Overrides default period in timer.

• msg.stopAll (boolean): If set to true, all timers and messages, regardless of topic, are discarded.

If in the node configuration or in msg.delay a value < 1 is given, the node prints a warning and uses a default period of 5 seconds instead.

Practical example

The example flow below (see message-rate-topic/examples/example-flow-message-rate-topic.json) configures a node with a rate of 1 message per topic per minute. You can test all available configurations with the insert nodes on the left side and see what the debug node on the right side produces to understand the node's behaviour.

Credits

Inspired and some code re-used from node-red-contrib-delay-topic-message.

Repository

GitHub - the nodes github repository