func()

in components/otelopscol/receiver/mongodbreceiver/metrics.go [246:284]

• 31 lines of code
• 6 McCabe index (conditional complexity)

func (s *mongodbScraper) recordCacheOperations(now pcommon.Timestamp, doc bson.M, errs *scrapererror.ScrapeErrors) {
	// Collect Cache Hits & Misses if wiredTiger storage engine is used
	// WiredTiger.cache metrics are available in 3.0+
	// https://www.mongodb.com/docs/v4.0/reference/command/serverStatus/#serverstatus.wiredTiger.cache
	mongo30, _ := version.NewVersion("3.0")
	if s.mongoVersion.LessThan(mongo30) {
		return
	}

	storageEngine, err := dig(doc, []string{"storageEngine", "name"})
	if err != nil {
		errs.AddPartial(1, errors.New("failed to find storage engine for cache operations"))
		return
	}
	if storageEngine != "wiredTiger" {
		// mongodb is using a different storage engine and this metric can not be collected
		return
	}

	metricPath := []string{"wiredTiger", "cache", "pages read into cache"}
	metricName := "mongodb.cache.operations"
	cacheMissVal, err := collectMetric(doc, metricPath)
	if err != nil {
		errs.AddPartial(2, fmt.Errorf(collectMetricWithAttributes, metricName, "miss, hit", err))
		return
	}
	s.mb.RecordMongodbCacheOperationsDataPoint(now, cacheMissVal, metadata.AttributeTypeMiss)

	cacheHitPath := []string{"wiredTiger", "cache", "pages requested from the cache"}
	cacheHitName := "mongodb.cache.operations"
	cacheHitVal, err := collectMetric(doc, cacheHitPath)
	if err != nil {
		errs.AddPartial(1, fmt.Errorf(collectMetricWithAttributes, cacheHitName, "hit", err))
		return
	}

	cacheHits := cacheHitVal - cacheMissVal
	s.mb.RecordMongodbCacheOperationsDataPoint(now, cacheHits, metadata.AttributeTypeHit)
}