go-redis/redis · error

no data returned

Error message

no data returned

What it means

Returned by ProcessAggregateResult when the RESP2 FT.AGGREGATE reply array is empty (len 0). The expected RESP2 layout is [total, row, row, ...] with at least the total count, so a zero-length slice means no usable data was returned. This is a client-side decoding guard, not a server-issued error string.

Source

Thrown at search_commands.go:917

		if options.Params != nil {
			queryArgs = append(queryArgs, "PARAMS", len(options.Params)*2)
			for key, value := range options.Params {
				queryArgs = append(queryArgs, key, value)
			}
		}

		if options.DialectVersion > 0 {
			queryArgs = append(queryArgs, "DIALECT", options.DialectVersion)
		} else {
			queryArgs = append(queryArgs, "DIALECT", 2)
		}
	}
	return queryArgs, nil
}

func ProcessAggregateResult(data []interface{}) (*FTAggregateResult, error) {
	if len(data) == 0 {
		return nil, fmt.Errorf("no data returned")
	}

	total, ok := data[0].(int64)
	if !ok {
		return nil, fmt.Errorf("invalid total format")
	}

	rows := make([]AggregateRow, 0, len(data)-1)
	for _, row := range data[1:] {
		fields, ok := row.([]interface{})
		if !ok {
			return nil, fmt.Errorf("invalid row format")
		}

		rowMap := make(map[string]interface{})
		for i := 0; i < len(fields); i += 2 {
			key, ok := fields[i].(string)
			if !ok {

View on GitHub (pinned to 36d97525cd)

Solutions

1. Inspect cmd.RawVal() / cmd.RawResult() to confirm the reply was actually an empty array.
2. Verify the protocol negotiated with the server (Options.Protocol 2 vs 3) matches the reply type the server sent.
3. Reproduce the same FT.AGGREGATE with redis-cli to see whether the empty reply originates at the server.
4. If a proxy is in the path, bypass it to localize the issue.

res, err := cmd.Result()
if err != nil {
    if errors.Is(err, /* wrap of */ errors.New("no data returned")) || err.Error() == "no data returned" {
        raw, _ := cmd.RawResult()
        log.Printf("empty aggregate reply, raw=%v", raw)
    }
    return nil, err
}

When it happens

Trigger: AggregateCmd.readReply decoding a RESP2 reply whose top-level array has zero elements. Triggered during response decoding; the server returned [] rather than the expected [N, ...rows].

Common situations: A proxy or middleware stripped the response. An unexpected RESP3 reply being interpreted as RESP2 (or vice versa). A server bug returning an empty array. Connection/command instrumentation mangling the frame. Very rarely, an upstream error swallowed into an empty reply.

Related errors

• odd-length key/value array of length %d
• invalid total format
• invalid row format
• invalid field key format
• redis: COLLECT value has type %T, want array of entries

AI-assisted analysis of go-redis/redis@36d97525cd (2026-08-06). Data as JSON: /data/errors/1121fdeff87e750a.json. Report an issue: GitHub.