jaegertracing/jaeger · error

failed to marshal map attribute %q: %w

Error message

failed to marshal map attribute %q: %w

What it means

buildMapAttributeCondition serializes a map-typed attribute via marshalValueForQuery before building the @map@ condition. A marshal failure is wrapped with this message, naming the attribute key, and aborts query construction.

Source

Thrown at internal/storage/v2/clickhouse/tracestore/query_builder.go:253

	return append(args, key, value, key, value, key, value, key, value, key, value)
}

func buildBytesAttributeCondition(q *strings.Builder, args []any, key string, attr pcommon.Value) []any {
	return buildSimpleAttributeCondition(q, args, "@bytes@"+key, pcommon.ValueTypeBytes, base64.StdEncoding.EncodeToString(attr.Bytes().AsRaw()))
}

func buildSliceAttributeCondition(q *strings.Builder, args []any, key string, attr pcommon.Value) ([]any, error) {
	b, err := marshalValueForQuery(attr)
	if err != nil {
		return args, fmt.Errorf("failed to marshal slice attribute %q: %w", key, err)
	}
	return buildSimpleAttributeCondition(q, args, "@slice@"+key, pcommon.ValueTypeSlice, b), nil
}

func buildMapAttributeCondition(q *strings.Builder, args []any, key string, attr pcommon.Value) ([]any, error) {
	b, err := marshalValueForQuery(attr)
	if err != nil {
		return args, fmt.Errorf("failed to marshal map attribute %q: %w", key, err)
	}
	return buildSimpleAttributeCondition(q, args, "@map@"+key, pcommon.ValueTypeMap, b), nil
}

func parseStringToTypedValue(key string, attr pcommon.Value, t pcommon.ValueType) (typedAttributeValue, error) {
	switch t {
	case pcommon.ValueTypeBool:
		b, parseErr := strconv.ParseBool(attr.Str())
		if parseErr != nil {
			return typedAttributeValue{}, fmt.Errorf("failed to parse bool attribute %q: %w", key, parseErr)
		}
		return typedAttributeValue{key: key, value: b, valueType: t}, nil
	case pcommon.ValueTypeDouble:
		f, parseErr := strconv.ParseFloat(attr.Str(), 64)
		if parseErr != nil {
			return typedAttributeValue{}, fmt.Errorf("failed to parse double attribute %q: %w", key, parseErr)
		}
		return typedAttributeValue{key: key, value: f, valueType: t}, nil

View on GitHub (pinned to 806f444784)

Solutions

1. Check the wrapped error to identify which map value failed to serialize
2. Flatten nested map values into string/int entries before querying
3. Pre-marshal map attributes in the caller to catch issues early
4. Restrict query attributes to maps of scalar values

Example fix

// before: nested map value
m.PutVal("nested", pcommon.NewValueEmpty().SetEmptyMapVal())
// after: scalar values only
m.PutStr("nested", flattenedJSON)

for _, k := range attr.Map().Keys() {
    v := attr.MapVal()
    val, _ := v.Get(k)
    t := val.Type()
    if t == pcommon.ValueTypeMap || t == pcommon.ValueTypeSlice {
        return fmt.Errorf("map attribute %q has non-scalar value %q", key, k)
    }
}

func isScalarOnlyMap(v pcommon.Value) bool {
    if v.Type() != pcommon.ValueTypeMap { return false }
    ok := true
    v.Map().Range(func(_ string, val pcommon.Value) bool {
        if val.Type() == pcommon.ValueTypeMap || val.Type() == pcommon.ValueTypeSlice {
            ok = false
        }
        return ok
    })
    return ok
}

traceIDs, err := store.FindTraceIDs(ctx, query)
if err != nil && strings.Contains(err.Error(), "failed to marshal map attribute") {
    log.Warn("unserializable map attribute in query", "err", err)
    return err
}

When it happens

Trigger: A FindTraceIDs query includes a map attribute whose values cannot be marshaled — e.g. a map containing nested unsupported value types or a corrupt pcommon.Value map.

Common situations: Passing OTLP-derived map attributes (e.g. http.request.headers) with nested containers into the search API; programmatic construction of malformed map values.

Related errors

• failed to marshal slice attribute %q: %w
• failed to parse bool attribute %q: %w
• failed to parse double attribute %q: %w
• failed to parse int attribute %q: %w
• unsupported attribute type %v for key %q

AI-assisted analysis of jaegertracing/jaeger@806f444784 (2026-09-01). Data as JSON: /api/errors/d9d81fc1d6275f7f. Report an issue: GitHub.