<p>It's probably something obvious but I don't seem to find a solution for joining 2 vectors in prometheus.</p>

<pre><code>sum(
  rabbitmq_queue_messages{queue=~".*"}
) by (queue)
* 
on (queue) group_left max(
  label_replace(
    kube_deployment_labels{label_daemon_name!=""},
    "queue",
    "$1",
    "label_daemon_queue_name",
    "(.*)"
  )
) by (deployment, queue)
</code></pre>

<p>Below a picture of the output of the two separate vectors.</p>

<p><a href="https://i.stack.imgur.com/lGlFH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lGlFH.png" alt="enter image description here"></a></p>

<p>Group left has the many on the left, so you've got the factors to the <code>*</code> the wrong way around. Try it the other way.</p>
