task-received events count greater than task-sent events count

[majamassarini]

I don't know if this is a real issue, probably it is more something that I can't understand and I need help with.

We noticed that when we have problems with the redis backend we are not aware of the tasks not being processed looking at the grafana flower dashboard.
I thought that having a graph monitoring the ratio of task-sent/task-received events could help us detect an underlying problem. Then I discovered that for some of our tasks we have a task-received event count greater than the task-sent event count and I can't understand how this is possible. I thought that a task has to be sent before being received.

Looking in the celery project I saw that the task-sent signal is now deprecated in favour of the before-task-publish and after-task-publish but I can't see these events mapped in flower.

Thank you for any help you can give me.