objstore: Add uploaded TSDB bytes metric

[ritaCanavarro]

• I added CHANGELOG entry for this change.
• Change is not relevant to the end user.

Changes

As suggested on thanos-io/thanos#6544 (review) the metric regarding the number of bytes the shipper has uploaded is best suited to be on the objstore. Therefore, this PR aims to add it to the objstore.go class.

Verification

I updated the TestTimingTracingReader test in objstore_test.go but I can add more tests if needed.

Thanks!

[bwplotka]

Epic! Good start, some suggestions for the start (:

Approved CI, will try to fix setting so it allows you to use CI without approvals

[simonswine]

I was separately working in exposing the fetched bytes as a histogram. Wonder if it makes sense to integrate both of our work into a single histogram: #69

[ritaCanavarro]

I was separately working in exposing the fetched bytes as a histogram. Wonder if it makes sense to integrate both of our work into a single histogram: #69

Hi @simonswine, if I understood correctly, it seems that we are working on different subjects so perhaps we should keep our PRs separated.

[bwplotka]

Merged your PR @simonswine.

I think @simonswine has a good point. We have two options:

A. Since we have both total fetched and distribution of fetched bytes per op, we could have similar for written bytes (total and later histogram in separate PR)
B. Although histogram's _sum might gives the same info as total counter, so we could skip adding upload bytes and focus in this PR to only add histogram (this should be easy @ritaCanavarro - just change type to histogram and use "Observe" instead of increments).

I don't have strong opinion, I trust @simonswine you have good judgment here. Would you like to help @ritaCanavarro to get this contribution to mergable state? 🤗

[bwplotka]

Also, @ritaCanavarro you need to rebase now (:

[simonswine]

I am also okay with both options.

And of course happy to help out @ritaCanavarro with this contribution.

[ritaCanavarro]

@bwplotka will work on the changes alongside @simonswine (thanks for the help!).

[simonswine]

Thank you @ritaCanavarro for putting the hard work in. I think we have it working, just a few more clean-ups as per my other comments

[simonswine]

@ritaCanavarro thanks for looking into this, I another pass and I noticed a few little things, but I think it is time to get more eyes on this

[fpetkovski]

Looks good from my side, thank you 🎖️

[fpetkovski]

@simonswine would you like to take another look before we merge this one?

[simonswine]

Yes I think this LGTM 🚀