jaegertracing/jaeger · error

nil search response

Error message

nil search response

What it means

This error is raised by aggregationKeys in service_operation.go when the Elasticsearch SearchResponse pointer itself is nil. A nil response cannot carry any aggregation data, so the function fails fast; in contrast, a non-nil response with no Aggregations section yields an empty slice rather than an error.

Source

Thrown at internal/storage/v2/elasticsearch/tracestore/core/service_operation.go:181

	resp, err := s.searcher.Search(ctx, indices, esclient.SearchRequest{
		Size:  0,
		Query: query.NewTermQuery(serviceName, service),
		Aggregations: map[string]query.Aggregation{
			operationsAggregation: query.NewTermsAggregation(operationNameField).Size(maxDocCount),
		},
	})
	if err != nil {
		return nil, fmt.Errorf("search operations failed: %w", err)
	}
	return aggregationKeys(resp, operationsAggregation)
}

// aggregationKeys extracts the bucket keys of a named terms aggregation. A
// response with no aggregations yields an empty slice; a response missing the
// requested aggregation is an error.
func aggregationKeys(resp *esclient.SearchResponse, name string) ([]string, error) {
	if resp == nil {
		return nil, errors.New("nil search response")
	}
	if resp.Aggregations == nil {
		return []string{}, nil
	}
	agg, ok := resp.Aggregations.Terms(name)
	if !ok {
		return nil, errors.New("could not find aggregation of " + name)
	}
	keys := make([]string, 0, len(agg.Buckets))
	for _, bucket := range agg.Buckets {
		keys = append(keys, bucket.Key)
	}
	return keys, nil
}

func hashCode(s dbmodel.Service) string {
	h := fnv.New64a()
	h.Write([]byte(s.ServiceName))

View on GitHub (pinned to 806f444784)

Solutions

1. Ensure the searcher/client always returns either a valid response or a non-nil error, and check errors before using the response.
2. Fix mock implementations used in tests to return a non-nil SearchResponse or an error.
3. If a nil response with nil error is reproducible, report/investigate the underlying client call for transport failures.

Example fix

// before
resp, err := searcher.Search(ctx, req)
keys, err := aggregationKeys(resp, aggName) // panics/nils if resp==nil and err==nil
// after
resp, err := searcher.Search(ctx, req)
if err != nil || resp == nil { return err }
keys, err := aggregationKeys(resp, aggName)

if resp == nil {
    return fmt.Errorf("searcher returned nil response")
}

func validResponse(r *esclient.SearchResponse) bool { return r != nil }

keys, err := aggregationKeys(resp, name)
if err != nil && err.Error() == "nil search response" {
    // treat as upstream client/transport failure; retry or surface 502
}

When it happens

Trigger: getServices or getOperations receiving a nil *SearchResponse from the searcher — typically when the underlying ES client transport fails in a way that yields a nil response alongside an error, or a test/mock returning (nil, nil).

Common situations: Custom or mocked searcher implementations returning nil responses without errors; lower-level client bugs or unexpected transport conditions; incorrect error handling upstream that lets a nil response propagate.

Related errors

• could not find aggregation of traceIDs
• could not find aggregation of
• root span top-hit missing _source
• file must begin with '['
• max spans count reached

AI-assisted analysis of jaegertracing/jaeger@806f444784 (2026-09-01). Data as JSON: /api/errors/2581a67b622b8cb1. Report an issue: GitHub.