SD-11577: decouple kv namespace from scrape interval

Author: rtalvarez

main.go

@@ -25,6 +25,11 @@ var (
 	cftimeout time.Duration
 	gql       *GraphQL
 	log       = logrus.New()
+
+	// kvNamespaceCache maps accountID -> namespaceID -> namespace name.
+	// Written by refreshKVNamespaceCache, read by fetchKVAnalytics.
+	kvNamespaceCache   = make(map[string]map[string]string)
+	kvNamespaceCacheMu sync.RWMutex
 )
 
 // var (
@@ -151,6 +156,30 @@ func fetchMetrics(deniedMetricsSet MetricsSet) {
 	wg.Wait()
 }
 
+func refreshKVNamespaceCache() {
+	accounts := fetchAccounts()
+	newCache := make(map[string]map[string]string, len(accounts))
+	for _, a := range accounts {
+		nsMap, err := fetchKVNamespaces(a.ID)
+		if err != nil {
+			log.Warnf("failed to refresh KV namespace cache for account %s: %v", a.ID, err)
+			continue
+		}
+		newCache[a.ID] = nsMap
+	}
+
+	kvNamespaceCacheMu.Lock()
+	kvNamespaceCache = newCache
+	kvNamespaceCacheMu.Unlock()
+	log.Info("KV namespace cache refreshed")
+}
+
+func getKVNamespaceMap(accountID string) map[string]string {
+	kvNamespaceCacheMu.RLock()
+	defer kvNamespaceCacheMu.RUnlock()
+	return kvNamespaceCache[accountID]
+}
+
 func runExporter() {
 	cfgMetricsPath := viper.GetString("metrics_path")
 
@@ -174,6 +203,14 @@ func runExporter() {
 	log.Debugf("Metrics set: %v", metricsSet)
 	mustRegisterMetrics(metricsSet)
 
+	// Populate KV namespace cache at boot, then refresh every 5 minutes.
+	refreshKVNamespaceCache()
+	go func() {
+		for range time.NewTicker(5 * time.Minute).C {
+			refreshKVNamespaceCache()
+		}
+	}()
+
 	scrapeInterval := time.Duration(viper.GetInt("scrape_interval")) * time.Second
 	log.Info("Scrape interval set to ", scrapeInterval)
 

prometheus.go

@@ -631,11 +631,7 @@ func fetchKVAnalytics(account cfaccounts.Account, wg *sync.WaitGroup, deniedMetr
 	wg.Add(1)
 	defer wg.Done()
 
-	namespaceMap, err := fetchKVNamespaces(account.ID)
-	if err != nil {
-		log.Error("failed to fetch KV namespaces for account ", account.ID, ": ", err)
-		return
-	}
+	namespaceMap := getKVNamespaceMap(account.ID)
 
 	r, err := fetchKVOperations(account.ID)
 	if err != nil {