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Prefer HOLD-based reweights to prevent rewinding-induced negative edges#86

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karalekas merged 14 commits intomainfrom
prefer-hold-reweights
Sep 28, 2025
Merged

Prefer HOLD-based reweights to prevent rewinding-induced negative edges#86
karalekas merged 14 commits intomainfrom
prefer-hold-reweights

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@karalekas karalekas commented Sep 26, 2025

Ran into the following error while running a simulation:

Running CHECK-PONG didn't fix a negative-weight edge:
#<MESSAGE-PONG @NIL
  RECOMMENDATION=GRAFT
  WEIGHT=-1
  EDGES=(#<11226>--->#<11237> #<11241>--->#<11226>)
  SOURCE-ID=#<((2, 15), 14)>
  SOURCE-ROOT=#<11241>
  TARGET-ROOT=#<11226>
  ROOT-BUCKET=NIL 358964>

Digging deeper, it like it’s an unfortunately-timed simultaneous reweight and rewind. The rewind causes a negative node to increase in weight, which of course is then not involved in the rewind checking because it is a negative node and therefore doesn’t send pings during scans.

This can (seemingly) be resolved by bumping non-zero HOLDs (aka reweights) in priority and locking root buckets.

IMG_2331

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didn’t read super duper closely, but at a glance i only see one (repeated) style concern

@karalekas karalekas merged commit 1b88c68 into main Sep 28, 2025
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@karalekas karalekas deleted the prefer-hold-reweights branch September 28, 2025 22:15
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2 participants