Best way to calculate average message size

[Gildas Léauté]

Hi team,

I have a VerneMQ cluster deployed (3 nodes) , with various clients sending various publishes messages of various size. I am trying to come up with the best method to calculate the average size of a publish message.

So far, I haven't found a dedicated metric for this. Therefore here is my current method :

- get the average number of publish / per second :

sum(irate(mqtt_publish_received{mqtt_version="4"}[10s]))

322req/sec

- get the average bytes received (or should I use cluster_bytes_received ?) :

sum(irate(bytes_received[10s]))

310942 bytes/sec

And simply divide : around 1Kbyte / req

Anyone having the same need and maybe found something more precise ?

Regards

 

[André Fatton]

Hi Gildas,

I think what you do makes sense and is the closest you can get to average the incoming message payload size.

bytes_received will come from the MQTT sessions (TCP and Websocket). cluster_bytes_received will measure bytes received coming for inter-node message forwarding. You should not use that for measuring, as you will already have your data point in bytes_received for every incoming message.

Hope this helps :)

Best,

André