TSLCP: Chain density

[fmaste]

Description

TraceBlockContext (block,slot)	sl	%	anchor length
(0, 0)	-	0 % 0	0
(1, 2)	2	X % 0	1
(2, 8)	6	0 % 6	2
(3, 56)	48	1 % 54	3
(4, 93)	37	2 % 91	4
(5, 156)	63	3 % 154	5
(6, 186)	30	4 % 184	6
(7, 199)	13	5 % 197	7
(8, 238)	39	6 % 236	8
(9, 245)	7	7 % 243	9

x = 18446744073709551615
(maxBound :: Word64)

Timeline obtained from the legacy tracing system:

https://github.com/IntersectMBO/cardano-node/blame/5264a7cd77a428ed04e25a11f22aba920ec399a6/cardano-node/src/Cardano/Tracing/Tracers.hs#L1773

• 2019-10: Chain density design
• • tracing chain quality #250
• 2019-11: Implementation
• • [#250] tracing chain density and display in LiveView#261
• • Commit e992b94
• 2020-01: Only whitespace
• • [CAD-402] Add tracers for the block forge microbenchmarking. #464
• • Commit a7a0a45
• 2020-02:
• • Update to latest version of ouroboros-network and other deps #569
• • Commit 75025b9
• • blockN = unBlockNo $ fromMaybe 1 (AF.headBlockNo frag) -> blockN = unBlockNo $ fromWithOrigin (BlockNo 1) (AF.headBlockNo frag)
• 2020-12: Extract function
• • CAD-2069: Tracing changes supporting K=1000
• • Commit df847ed

Related

• CAD-2907 Tracing: SendFetchRequest
• • CAD-2907 tracing: a more precise AF length calculation

As used now in monitoring

https://github.com/input-output-hk/cardano-playground/blob/main/flake/opentofu/grafana/dashboards/cardano-node.json#L326

Add your description here, if it fixes a particular issue please provide a
link
to the issue.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. These may include:
  • golden tests
  • property tests
  • roundtrip tests
  • integration tests
    See Runnings tests for more details
• Any changes are noted in the CHANGELOG.md for affected package
• The version bounds in .cabal files are updated
• CI passes. See note on CI. The following CI checks are required:
  • Code is linted with hlint. See .github/workflows/check-hlint.yml to get the hlint version
  • Code is formatted with stylish-haskell. See .github/workflows/stylish-haskell.yml to get the stylish-haskell version
  • Code builds on Linux, MacOS and Windows for ghc-8.10.7 and ghc-9.2.7
• Self-reviewed the diff

Note on CI

If your PR is from a fork, the necessary CI jobs won't trigger automatically for security reasons.
You will need to get someone with write privileges. Please contact IOG node developers to do this
for you.