Hacktoberfest 2026 : les issues que les mainteneurs ont marquées pour octobre, ouvertes et accessibles aux débutants. Parcourir les issues Hacktoberfest

Duplicate blocks in cache silently block subgraph indexing

Ouverte
#6,382 1 commentaire 0 réactions 1 personne assignée Voir sur GitHub

@incrypto32 y travaille déjà.

Depuis le 18/5/2026.

Évaluation

Cette issue n'a pas encore été évaluée.

Description

Summary

Duplicate blocks accumulating in the block cache (chainN.blocks) can cause subgraphs to stop indexing. The subgraph remains health=healthy and active=true but processes 0 blocks/s. The only symptom is an increasing blocks_behind count.

The error is only visible at DEBUG level:

Block stream produced a non-fatal error, error: block stream error Block 14500860 does not contain hash

This repeats every ~7 minutes indefinitely. The subgraph never fails or enters an unhealthy state — it just stops advancing.

Root cause

The block ingestor stores both branches of a reorg in the block cache without cleaning up orphaned entries. Under certain conditions (not fully characterized — it does not happen at every duplicate block), a subgraph hits a block where the hash it expects no longer resolves, causing the "does not contain hash" error loop.

It is unclear what exact combination of factors triggers the issue — the presence of duplicate blocks is a necessary condition, but there may be additional factors (e.g., specific reorg depth, timing of block ingestion vs subgraph processing).

Impact observed (production, ~250 subgraphs)

Chain Duplicate blocks Range checked Ratio
moonbeam 2,400+ 16,000 blocks ~15%
mainnet (Ethereum PoS) 1,382 full cache —
  • Blocked subgraphs can show very high reorg_count (779,742 for the moonbeam case)
  • The issue is silent — no WARN/ERROR at default log level, health stays healthy
  • Observed on chains using RPC polling (not firehose)

Workaround

Remove duplicate blocks from the cache and perform a short rewind:

-- Find duplicate blocks
SELECT number, count(*) FROM chainN.blocks
GROUP BY number HAVING count(*) > 1;

# Remove duplicates (or truncate the whole chain cache)
graphman chain check-blocks <chain> by-range -f <from> -t <to> --delete-duplicates
# or: graphman chain truncate <chain>

# Then rewind the stuck subgraph with the correct block hash
graphman rewind --force --block-number <N> --block-hash <correct_hash> <deployment>

Related

  • #4792 — reports the same duplicate block storage issue

Environment

  • graph-node v0.41.1
Langage dominant
Rust
Étoiles
3.2k
Forks
1.1k
Merge moyen
4 j 1 h
PR mergées (30 j)
1

Guide de contribution

Ouvrir le guide de contribution

Par où commencer

  1. Lisez l'issue en entier, puis le guide de contribution du projet.
  2. Signalez en commentaire que vous la prenez — cela évite que deux personnes fassent le même travail.
  3. Forkez le dépôt et travaillez sur une branche.
  4. Ouvrez une pull request qui référence le numéro de l'issue.

Autres issues de graphprotocol/graph-node

Toutes les issues de graphprotocol/graph-node

Issues similaires

Plus d'issues Rust

Recevez les nouvelles issues par e-mail

Un résumé court des issues GitHub adaptées aux débutants.