iotaledger / iota / 34424838898

70%

Build Type

push

github

Committed by web-flow

Commit Message

feat(starfish): select shard peers by block-stream latency (#12794)

# Description of change

- Track smoothed primary block-stream latency per peer and clear it on
disconnect.
- For each useful shard author, ask only the fastest peers needed to
provide enough shards and stake for reconstruction.
- Treat authors of missing ancestors as useful shard authors too, as the
header requests already do.
- Add two gauges for the latest selection: its peer count and the
slowest selected peer's block-stream latency.
- Drop the per-author `cordial_knowledge_useful_shards_authors` counter
(written per bundle under the connection lock; the new gauge covers it)
and the dead `useful_shards_from_peer` field of `UsefulAuthors`.
- Replace the dashboard's "Useful shard authors over time" panel with
panels for the two new gauges.

This limits shard traffic while leaving transaction synchronization
unchanged as the fallback.

## Links to any relevant issues

Fixes #12793.

## How the change has been tested

- [x] Basic tests (linting, compilation, formatting, unit/integration
tests)
- [x] Patch-specific tests (correctness, functionality coverage)
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have checked that new and existing unit tests pass locally with
my changes

Coverage Stats

408 of 411 new or added lines in 7 files covered. (99.27%)

184 existing lines in 34 files now uncovered.

180083 of 257687 relevant lines covered (69.88%)

447025.99 hits per line