Downsampling traces

[fmassot]

A user asked on Discord for a downsampling feature of traces.

The sampling of traces is generally done at the collector level. This is well explained in the OTEL documentation. Two sampling methods can be applied: Head Sampling or Tail Sampling.

Downsampling in Quickwit would mean that, after a given period of time, Quickwit will analyze splits and apply Head Sampling or Tail Sampling to reduce the index storage size.

This feature request needs more details. We should probably look first to other trace engines and evaluate the interest of such feature among Quickwit users.