uber
chore(histograms): dual-emitting persistence latency timers as histograms, by far our largest ones
persistence_latency_per_shard is by far our largest series-count timer (metric overall probably), at 37 million series internally.
Migrating this to histograms will raise that cardinality significantly, so it'll be a bit of an exciting one, though it's expected to go smoothly.
Since they're nearby and clearly related, I'm also migrating other histograms that cover persistence latency. These are "large" too, but nearly an order of magnitude smaller.
And PersistenceLatencyHistogram (manual buckets) has been renamed to PersistenceLatencyManualHistogram and deprecated - the buckets / precision are not changing very much, but the new buckets are subsettable.
This will be dual-emitted for "a while", but since the new buckets are so similar it should be very simple to migrate. It's unlikely to be more than a simple name change in queries.
Given the number of series involved in these timers/histograms, this should probably not be merged without also merging #7298 so they can be disabled if needed.
Signed-off-by: Steven L [email protected]
