dgraph-io/dgraph · error

downstream(%d) closed before Finish=true

Error message

downstream(%d) closed before Finish=true

What it means

After half-closing the downstream send, the relay drains the leader's responses waiting for the frame with Finish=true. If out.Recv() returns io.EOF instead, the leader closed its side without signalling completion, so the import result is unknown and this error is returned.

Source

Thrown at worker/import.go:427

		if req.Pkt == nil {
			return fmt.Errorf("unexpected empty request")
		}

		if req.Pkt.Done {
			// Forward Done, half-close downstream send.
			if err := out.Send(&api.StreamExtSnapshotRequest{Pkt: req.Pkt}); err != nil && !errors.Is(err, io.EOF) {
				return fmt.Errorf("send done downstream(%d): %w", groupId, err)
			}
			_ = out.CloseSend()

			// Drain downstream and relay upstream until Finish=true.
			for {
				if err := ctx.Err(); err != nil {
					return err
				}
				resp, err := out.Recv()
				if errors.Is(err, io.EOF) {
					return fmt.Errorf("downstream(%d) closed before Finish=true", groupId)
				}
				if err != nil {
					return fmt.Errorf("recv final downstream(%d): %w", groupId, err)
				}
				if err := in.Send(resp); err != nil {
					return fmt.Errorf("relay final upstream: %w", err)
				}
				if resp.Finish {
					glog.Infof("[import] [forward %d -> %d] finish", currentGroup, groupId)
					return nil
				}
			}
		}

		// Normal data chunk: send -> wait ack -> send upstream ack.
		if err := out.Send(&api.StreamExtSnapshotRequest{Pkt: req.Pkt}); err != nil {
			return fmt.Errorf("send data downstream(%d): %w", groupId, err)
		}

View on GitHub (pinned to 759e242be6)

Solutions

1. Check the leader's logs for the error that ended its handler before Finish
2. Re-run the import; the snapshot state may be incomplete
3. Ensure the leader has adequate disk/memory for finalizing an external snapshot
4. Remove idle-timeout intermediaries between the two alphas

// ensure leader resources before import so finalization can complete
precheckDiskAndMemory(leaderHost)

func finishedCorrectly(resp *api.StreamExtSnapshotResponse) bool {
    return resp != nil && resp.Finish // only Finish=true means success
}

if err != nil && strings.Contains(err.Error(), "closed before Finish=true") {
    // outcome unknown: check leader logs, then re-run the import
}

When it happens

Trigger: The leader's StreamExtSnapshot server handler returned or closed the stream before sending Finish=true: it errored on its own snapshot pipeline, was killed, or its context was cancelled.

Common situations: Leader hit an internal error (disk full, memory) mid-finalization; leader restarted at the very end of the import; a proxy closed the connection after inactivity during the leader's final flush.

Related errors

• unexpected empty request
• while calling MovePredicate
• failed to establish stream with leader: %v
• failed to send forward request: %v
• recv upstream(%d): %w

AI-assisted analysis of dgraph-io/dgraph@759e242be6 (2026-09-01). Data as JSON: /api/errors/f22121962719395e. Report an issue: GitHub.