Fix: Skip the non-exist namespaces when there are multiple mongo instance metrics to scrape

Signed-off-by: LinPr <314573849@qq.com>

Author: LinPr

exporter/collstats_collector.go

@@ -78,7 +78,7 @@ func (d *collstatsCollector) collect(ch chan<- prometheus.Metric) {
 		collections = fromMapToSlice(onlyCollectionsNamespaces)
 	} else {
 		var err error
-		collections, err = checkNamespacesForViews(d.ctx, client, d.collections)
+		collections, err = checkNamespacesForViews(d.ctx, client, d.collections, logger)
 		if err != nil {
 			logger.Error("cannot list collections", "error", err.Error())
 			return

exporter/common.go

@@ -18,6 +18,7 @@ package exporter
 import (
 	"context"
 	"fmt"
+	"log/slog"
 	"sort"
 	"strings"
 
@@ -163,7 +164,7 @@ func unique(slice []string) []string {
 	return list
 }
 
-func checkNamespacesForViews(ctx context.Context, client *mongo.Client, collections []string) ([]string, error) {
+func checkNamespacesForViews(ctx context.Context, client *mongo.Client, collections []string, logger *slog.Logger) ([]string, error) {
 	onlyCollectionsNamespaces, err := listAllCollections(ctx, client, collections, nil, true)
 	if err != nil {
 		return nil, err
@@ -183,6 +184,9 @@ func checkNamespacesForViews(ctx context.Context, client *mongo.Client, collecti
 		}
 
 		if _, ok := namespaces[collection]; !ok {
+			if logger != nil {
+				logger.Warn("namespace %s is a view or does not exist, cannot be used for collstats/indexstats", collection)
+			}
 			continue
 		}
 

exporter/common_test.go

@@ -199,13 +199,13 @@ func TestCheckNamespacesForViews(t *testing.T) {
 	defer cleanupDB(ctx, client)
 
 	t.Run("Views in provided collection list (should fail)", func(t *testing.T) {
-		filtered, err := checkNamespacesForViews(ctx, client, []string{"testdb01.col01", "testdb01.system.views", "testdb01.view01"})
+		filtered, err := checkNamespacesForViews(ctx, client, []string{"testdb01.col01", "testdb01.system.views", "testdb01.view01"}, nil)
 		assert.NoError(t, err)
 		assert.Equal(t, []string{"testdb01.col01", "testdb01.system.views"}, filtered)
 	})
 
 	t.Run("No Views in provided collection list", func(t *testing.T) {
-		filtered, err := checkNamespacesForViews(ctx, client, []string{"testdb01.col01", "testdb01.system.views"})
+		filtered, err := checkNamespacesForViews(ctx, client, []string{"testdb01.col01", "testdb01.system.views"}, nil)
 		assert.NoError(t, err)
 		assert.Equal(t, []string{"testdb01.col01", "testdb01.system.views"}, filtered)
 	})

exporter/indexstats_collector.go

@@ -77,7 +77,7 @@ func (d *indexstatsCollector) collect(ch chan<- prometheus.Metric) {
 		collections = fromMapToSlice(onlyCollectionsNamespaces)
 	} else {
 		var err error
-		collections, err = checkNamespacesForViews(d.ctx, client, d.collections)
+		collections, err = checkNamespacesForViews(d.ctx, client, d.collections, logger)
 		if err != nil {
 			logger.Error("cannot list collections", "error", err.Error())