Upgrade mimir-prometheus

[codesome]

mimir-prometheus is being synced with upstream Prometheus (here) and it comes with few changes. So I am opening this PR with a checklist of things to do before/when upgrading mimir-prometheus here.

• Prometheus changed the block meta format for identifying out of order block. We need to update mimir-prometheus to identify both old and new way for the next Mimir release and get rid of old way after 2 releases (that is the usual time to wait to remove something, right?).
• Overlapping compaction is now enabled by default in TSDB. Make sure to explicitly set it to false for ingesters.

[56quarters]

I merged the update to Prometheus in Mimir without noticing this issue. Overlapping compaction is is false in Mimir but I didn't update mimir-prometheus to identify old and new meta formats. I will begin working on that now.

[56quarters]

If I understand correctly:

• Upstream Prometheus uses a hint in the BlockMetaCompaction struct to indicate if a block contains OOO samples.
• Our fork previously used an OutOfOrder bool directly only the BlocksMeta struct.
• Now, our fork uses both the OutOfOrder bool and the compaction hint to determine if a block contains OOO samples.

So it seems like the first task of changing mimir-prometheus to identify the old and new way is already done (as part of grafana/mimir-prometheus#337)? Can you confirm if this is the case @codesome or have I missed something?

[codesome]

@56quarters you are right, everything is taken care.

[56quarters]

Excellent. I'll open another issue to remove the use of the OutOfOrder bool later. OOO is an experimental feature so I don't think we're under any obligation beyond mentioning it in the changelog. On the other hand, it probably makes sense to do one Mimir release supporting both ways before removing the OutOfOrder bool so we're not purposefully breaking people that wanted to try the feature out.