hyperledger/fabric · error

failed to get last block

Error message

failed to get last block

What it means

NewChain fetches the last block of the channel ledger (support.Block(support.Height()-1)) to initialize chain state (block number, appended terms). If that block is nil despite the height, the ledger is inconsistent and chain startup is aborted with 'failed to get last block'. This prevents initializing raft on top of an unreadable ledger tip.

Source

Thrown at orderer/consensus/etcdraft/chain.go:261

	}

	sizeLimit := opts.SnapshotIntervalSize
	if sizeLimit == 0 {
		sizeLimit = DefaultSnapshotIntervalSize
	}

	// get block number in last snapshot, if exists
	var snapBlkNum uint64
	cc := &raftpb.ConfState{}
	if s := storage.Snapshot(); !raft.IsEmptySnap(s) {
		b := protoutil.UnmarshalBlockOrPanic(s.GetData())
		snapBlkNum = b.GetHeader().GetNumber()
		cc = s.GetMetadata().GetConfState()
	}

	b := support.Block(support.Height() - 1)
	if b == nil {
		return nil, errors.Errorf("failed to get last block")
	}

	c := &Chain{
		configurator:      conf,
		rpc:               rpc,
		channelID:         support.ChannelID(),
		raftID:            opts.RaftID,
		submitC:           make(chan *submit),
		applyC:            make(chan apply),
		haltC:             make(chan struct{}),
		doneC:             make(chan struct{}),
		startC:            make(chan struct{}),
		snapC:             make(chan *raftpb.Snapshot),
		errorC:            make(chan struct{}),
		gcC:               make(chan *gc),
		observeC:          observeC,
		support:           support,
		fresh:             fresh,

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Check the orderer log for prior ledger read errors and validate the channel's block files (blockindex/ledger data integrity).
2. Remove and re-join the channel via the participation API to rebuild the ledger from other consenters.
3. Restore the ledger from a healthy snapshot or copy block files from a working orderer of the same channel (with the orderer stopped).
4. Verify disk health and free space; replace failing storage before restarting.

b := support.Block(support.Height() - 1)
if b == nil {
    return errors.New("ledger tip unreadable; re-sync channel before starting chain")
}

When it happens

Trigger: Creating a chain where support.Height() > 0 but the last block cannot be retrieved — ledger truncation/corruption, height advanced but block data missing, or a race with ledger initialization.

Common situations: Orderer crash mid-block-write corrupting the ledger tip; snapshot restore leaving the ledger height inconsistent; FileLedger directory partially deleted or on a failing disk.

Related errors

• unable to retrieve block [%d]
• failed to restore persisted raft data: %s
• chain is stopped
• chain is not started
• failed to process Raft Step message: %s

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/9203aa553d46663b. Report an issue: GitHub.