Filip and Matej's comments

Signed-off-by: haanhvu <haanh6594@gmail.com>

pkg/exemplars/tsdb.go

@@ -18,7 +18,8 @@ import (
 
 // TSDB allows fetching exemplars from a TSDB instance.
 type TSDB struct {
-	db        storage.ExemplarQueryable
+	db storage.ExemplarQueryable
+
 	extLabels labels.Labels
 	mtx       sync.RWMutex
 }

pkg/receive/config.go

@@ -44,7 +44,7 @@ type HashringConfig struct {
 	Tenants        []string          `json:"tenants,omitempty"`
 	Endpoints      []string          `json:"endpoints"`
 	Algorithm      HashringAlgorithm `json:"algorithm,omitempty"`
-	ExternalLabels []string          `json:"external_labels,omitempty"`
+	ExternalLabels map[string]string `json:"external_labels,omitempty"`
 }
 
 // ConfigWatcher is able to watch a file containing a hashring configuration

pkg/receive/multitsdb.go

@@ -567,26 +567,14 @@ func (t *MultiTSDB) startTSDB(logger log.Logger, tenantID string, tenant *tenant
 	reg := prometheus.WrapRegistererWith(prometheus.Labels{"tenant": tenantID}, t.reg)
 	reg = NewUnRegisterer(reg)
 
-	lset := labelpb.ExtendSortedLabels(t.labels, labels.FromStrings(t.tenantLabelName, tenantID))
+	initialLset := labelpb.ExtendSortedLabels(t.labels, labels.FromStrings(t.tenantLabelName, tenantID))
 
-	// Extract tenant's external labels from hashring configs.
-	// If one tenant appears in multiple hashring configs,
-	// only the external label set from the first hashring config is applied.
-hcLoop:
-	for _, hc := range t.hashringConfigs {
-		for _, tenant := range hc.Tenants {
-			if tenant != tenantID {
-				continue
-			}
-
-			var err error
-			lset, err = parseAndExtendSortedLabels(lset, hc.ExternalLabels, t.logger)
-			if err != nil {
-				return errors.Wrap(err, "failed to parse external labels for tenant "+tenantID)
-			}
-
-			break hcLoop
-		}
+	lset, err := t.extractTenantsLabels(tenantID, initialLset)
+	if err != nil {
+		t.mtx.Lock()
+		delete(t.tenants, tenantID)
+		t.mtx.Unlock()
+		return err
 	}
 
 	dataDir := t.defaultTenantDataDir(tenantID)
@@ -691,9 +679,9 @@ func (t *MultiTSDB) SetHashringConfig(cfg []HashringConfig) error {
 
 				lset := labelpb.ExtendSortedLabels(t.labels, labels.FromStrings(t.tenantLabelName, tenantId))
 				var err error
-				lset, err = parseAndExtendSortedLabels(lset, hc.ExternalLabels, t.logger)
+				lset, err = extendLabels(lset, hc.ExternalLabels, t.logger)
 				if err != nil {
-					return errors.Wrap(err, "failed to parse external labels for tenant "+tenantId)
+					return errors.Wrap(err, "failed to extend external labels for tenant "+tenantId)
 				}
 
 				if t.tenants[tenantId].ship != nil {
@@ -863,29 +851,46 @@ func (u *UnRegisterer) MustRegister(cs ...prometheus.Collector) {
 	}
 }
 
-// Parse, sort, and extend external labels to an initial label set.
+// extractTenantsLabels extractes tenant's external labels from hashring configs.
+// If one tenant appears in multiple hashring configs,
+// only the external label set from the first hashring config is applied.
+func (t *MultiTSDB) extractTenantsLabels(tenantID string, initialLset labels.Labels) (labels.Labels, error) {
+	for _, hc := range t.hashringConfigs {
+		for _, tenant := range hc.Tenants {
+			if tenant != tenantID {
+				continue
+			}
+
+			lset, err := extendLabels(initialLset, hc.ExternalLabels, t.logger)
+			if err != nil {
+				return nil, errors.Wrap(err, "failed to extend external labels for tenant "+tenantID)
+			}
+			return lset, nil
+		}
+	}
+
+	return nil, nil
+}
+
+// extendLabels extends external labels of the initial label set.
 // If an external label shares same name with a label in the initial label set,
 // use the label in the initial label set and inform user about it.
-func parseAndExtendSortedLabels(labelSet labels.Labels, extend []string, logger log.Logger) (labels.Labels, error) {
+func extendLabels(labelSet labels.Labels, extend map[string]string, logger log.Logger) (labels.Labels, error) {
 	var extendLabels labels.Labels
-	for _, s := range extend {
-		parts := strings.SplitN(s, "=", 2)
-		if len(parts) != 2 {
-			return nil, errors.Errorf("unrecognized label %q", s)
-		}
-		if !model.LabelName.IsValid(model.LabelName(parts[0])) {
-			return nil, errors.Errorf("unsupported format for label %s", s)
+	for name, value := range extend {
+		if !model.LabelName.IsValid(model.LabelName(name)) {
+			return nil, errors.Errorf("unsupported format for label's name: %s", name)
 		}
-		extendLabels = append(extendLabels, labels.Label{Name: parts[0], Value: parts[1]})
+		extendLabels = append(extendLabels, labels.Label{Name: name, Value: value})
 	}
-	sort.Sort(extendLabels)
 
 	extendedLabelSet := make(labels.Labels, 0, len(labelSet)+len(extendLabels))
 	for len(labelSet) > 0 && len(extendLabels) > 0 {
 		d := strings.Compare(labelSet[0].Name, extendLabels[0].Name)
 		if d == 0 {
 			extendedLabelSet = append(extendedLabelSet, labelSet[0])
-			level.Info(logger).Log("msg", "Duplicate label's name "+extendLabels[0].Name+". Using initial label instead.")
+			level.Info(logger).Log("msg", "Duplicate label found. Using initial label instead.",
+				"label's name", extendLabels[0].Name)
 			labelSet, extendLabels = labelSet[1:], extendLabels[1:]
 		} else if d < 0 {
 			extendedLabelSet = append(extendedLabelSet, labelSet[0])
@@ -898,5 +903,7 @@ func parseAndExtendSortedLabels(labelSet labels.Labels, extend []string, logger
 	extendedLabelSet = append(extendedLabelSet, labelSet...)
 	extendedLabelSet = append(extendedLabelSet, extendLabels...)
 
+	sort.Sort(extendedLabelSet)
+
 	return extendedLabelSet, nil
 }