Method queryExemplars

pkg/ingester/ingester.go:1820–1872

(ctx context.Context, userID string, req *client.ExemplarQueryRequest)

}

func (i *Ingester) queryExemplars(ctx context.Context, userID string, req *client.ExemplarQueryRequest) (*client.ExemplarQueryResponse, error) {
	from, through, matchers, err := client.FromExemplarQueryRequest(i.matchersCache, req)
	if err != nil {
		return nil, err
	}

	i.metrics.queries.Inc()

	db, err := i.getTSDB(userID)
	if err != nil || db == nil {
		return &client.ExemplarQueryResponse{}, nil
	}

	if err = db.acquireReadLock(); err != nil {
		return &client.ExemplarQueryResponse{}, nil
	}
	defer db.releaseReadLock()

	q, err := db.ExemplarQuerier(ctx)
	if err != nil {
		return nil, err
	}

	// We will report *this* request in the error too.
	c, err := i.trackInflightQueryRequest()
	if err != nil {
		return nil, err
	}

	// It's not required to sort series from a single ingester because series are sorted by the Exemplar Storage before returning from Select.
	res, err := q.Select(from, through, matchers...)
	c()
	if err != nil {
		return nil, err
	}

	numExemplars := 0

	result := &client.ExemplarQueryResponse{}
	for _, es := range res {
		ts := cortexpb.TimeSeries{
			Labels:    cortexpb.FromLabelsToLabelAdapters(es.SeriesLabels),
			Exemplars: cortexpb.FromExemplarsToExemplarProtos(es.Exemplars),
		}

		numExemplars += len(ts.Exemplars)
		result.Timeseries = append(result.Timeseries, ts)
	}

	i.metrics.queriedExemplars.Observe(float64(numExemplars))

	return result, nil
}

// LabelValues returns all label values that are associated with a given label name.
func (i *Ingester) LabelValues(ctx context.Context, req *client.LabelValuesRequest) (resp *client.LabelValuesResponse, err error) {