Volume metrics question

[Maximebb]

I've looked around the documentation and experimented with the metrics our cluster is producing, and I can't figure out a way to measure our volume of messages accurately.

For context, I'm interested in learning more about the relationship between our system's performance and total published messages volume in size and count. With my current understanding, the following are what I should use

• rabbitmq_queue_messages_bytes -> shows the byte size of ready and unacked messages
• rabbitmq_channel_messages_published_total -> shows the number of messages published on an exchange
• rabbitmq_connection_incoming_bytes_total -> number of bytes received on connections

rabbitmq_queue_messages_bytes is close to showing me what I'm most interested in seeing, but since it's a gauge and not a counter, I can't rely on it to know how many bytes were sent through the queues. If I rely on rabbitmq_channel_messages_published_total and rabbitmq_connection_incoming_bytes_total, the average per message size this gives me is very far away from my assumptions. I know there's extra overhead in the connection size vs pure message size, but not as much as this is giving me.

Anyone has some insight on getting an accurate picture of the total size being published in our queues?