This patch reduces the number of metrics ScyllaDB generates.
Motivation: The combination of per-shard with per-scheduling group
generates a lot of metrics. When combined with histograms, which require
many metrics, the problem becomes even bigger.
The two tools we are going to use:
1. Replace per-shard histograms with summaries
2. Do not report unused metrics.
The storage_proxy stats holds information for the API and the metrics
layer. We replaced timed_rate_moving_average_and_histogram and
time_estimated_histogram with the unfied
timed_rate_moving_average_summary_and_histogram which give us an option
to report per-shard summaries instead of histogram.
All the counters, histograms, and summaries were marked as
skip_when_empty.
The API was modified to use
timed_rate_moving_average_summary_and_histogram.
Closes#11173
5ac20ac861