hyperledger/fabric · error

no cluster members to synchronize with

Error message

no cluster members to synchronize with

What it means

Raised in Synchronizer.synchronize when HeightsByEndpoints succeeds but returns an empty map — meaning there are zero cluster members to pull blocks from. The synchronizer refuses to proceed because block replication requires at least one reachable remote consenter.

Source

Thrown at orderer/consensus/smartbft/synchronizer.go:97

	return viewMetadata, lastConfigSqn
}

func (s *Synchronizer) synchronize() (*types.Decision, error) {
	blockPuller, err := s.BlockPullerFactory.CreateBlockPuller(s.Support, s.ClusterDialer, s.LocalConfigCluster, s.CryptoProvider)
	if err != nil {
		return nil, errors.Wrap(err, "cannot get create BlockPuller")
	}
	defer blockPuller.Close()

	heightByEndpoint, _, err := blockPuller.HeightsByEndpoints()
	if err != nil {
		return nil, errors.Wrap(err, "cannot get HeightsByEndpoints")
	}

	s.Logger.Infof("HeightsByEndpoints: %v", heightByEndpoint)

	if len(heightByEndpoint) == 0 {
		return nil, errors.New("no cluster members to synchronize with")
	}

	var heights []uint64
	for _, value := range heightByEndpoint {
		heights = append(heights, value)
	}

	targetHeight := s.computeTargetHeight(heights)
	startHeight := s.Support.Height()
	if startHeight >= targetHeight {
		return nil, errors.Errorf("already at height of %d", targetHeight)
	}

	targetSeq := targetHeight - 1
	seq := startHeight

	var blocksFetched int

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Ensure the channel configuration contains at least one other reachable consenter endpoint
2. If this is the only node, synchronization is unnecessary — verify the channel membership in the latest config block
3. Check earlier logs: if endpoints were probed and failed, fix connectivity so HeightsByEndpoints returns non-empty results
4. Re-add the missing orderers to the channel via a channel config update

// Ensure channel config has other consenters before expecting sync to work
consenters := sharedConfig.Consenters()
if len(consenters) <= 1 {
    // single-node channel: synchronization with others is impossible by design
}

// Sync degrades to local-ledger response; check that fallback explicitly
resp := synchronizer.Sync()
if resp.Latest.Height == s.Support.Height()-1 {
    // local fallback was used; treat as sync failure
}

When it happens

Trigger: HeightsByEndpoints returned an empty heightByEndpoint map, typically because the channel has no other consenter endpoints configured, or all endpoints were filtered out (e.g. only the node's own endpoint existed, or endpoint resolution discarded unreachable members).

Common situations: Single-node channel attempting to sync (nothing to sync with); channel config missing consenter entries; all other orderers removed from channel config; join/bootstrap mistakes leaving an orderer in a channel whose config it cannot see.

Related errors

• cannot get HeightsByEndpoints
• failed pulling block %d
• cannot get detect target height
• failed to get any blocks from SyncBuffer
• cannot get HeightsByEndpoints

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/42fd075b9ceb69bd. Report an issue: GitHub.