Hi,
Just a quick heads up, I've changed the way I report bytes added very slightly. Instead of returning "null" when a user has no bytes added, I'm now returning 0. This is to allow for more meaningful null values, like in the case of time_to_threshold. So from now on, if you see a null value in a metric report, it means that value will not be counted towards any aggregate.
Hopes that makes things a bit clearer and here's the patchset if you're curious:
https://gerrit.wikimedia.org/r/#/c/91495/
We'll merge/deploy this shortly.
Dan