hyperledger/fabric · error

failed pulling block %d

Error message

failed pulling block %d

What it means

getBlocksFromSyncBuffer guard: the synchronization loop finished but lastPulledBlock is still nil — not a single block could be pulled from the sync buffer despite a non-empty target height. The message names the block sequence that was being fetched.

Source

Thrown at orderer/consensus/smartbft/synchronizer_bft.go:274

			s.Logger.Debugf("Fetched and committed config block [%d] from cluster", seq)
		} else {
			s.Support.WriteBlockSync(block, nil)
			s.Logger.Debugf("Fetched and committed block [%d] from cluster", seq)
		}
		lastPulledBlock = block

		prevInLatestDecision := s.lastReconfig.InLatestDecision
		s.lastReconfig = s.OnCommit(lastPulledBlock)
		s.lastReconfig.InLatestDecision = s.lastReconfig.InLatestDecision || prevInLatestDecision
		s.Logger.Debugf("Last reconfig %+v", s.lastReconfig)
		seq++
		blocksFetched++
	}

	s.syncBuff.Stop()

	if lastPulledBlock == nil {
		return nil, errors.Errorf("failed pulling block %d", seq)
	}

	s.Logger.Infof("Finished synchronizing with cluster, fetched %d blocks, starting from block [%d], up until and including block [%d]",
		blocksFetched, startHeight, lastPulledBlock.Header.Number)

	return lastPulledBlock, nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

  1. Check connectivity to the deliver sources (other consenters)
  2. Retry synchronization when the cluster is healthier
Defensive patterns

Strategy: retry

When it happens

Trigger: Thrown at orderer/consensus/smartbft/synchronizer_bft.go:274 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/ffb55d12120577b1. Report an issue: GitHub.