Add extra wired tiger cache metrics to mongodb input (#3281)

Author: phenomenes

plugins/inputs/mongodb/mongodb_data.go

@@ -77,6 +77,21 @@ var WiredTigerStats = map[string]string{
 	"percent_cache_used":  "CacheUsedPercent",
 }
 
+var WiredTigerExtStats = map[string]string{
+	"wtcache_tracked_dirty_bytes":          "TrackedDirtyBytes",
+	"wtcache_current_bytes":                "CurrentCachedBytes",
+	"wtcache_max_bytes_configured":         "MaxBytesConfigured",
+	"wtcache_app_threads_page_read_count":  "AppThreadsPageReadCount",
+	"wtcache_app_threads_page_read_time":   "AppThreadsPageReadTime",
+	"wtcache_app_threads_page_write_count": "AppThreadsPageWriteCount",
+	"wtcache_bytes_written_from":           "BytesWrittenFrom",
+	"wtcache_bytes_read_into":              "BytesReadInto",
+	"wtcache_pages_evicted_by_app_thread":  "PagesEvictedByAppThread",
+	"wtcache_pages_queued_for_eviction":    "PagesQueuedForEviction",
+	"wtcache_server_evicting_pages":        "ServerEvictingPages",
+	"wtcache_worker_thread_evictingpages":  "WorkerThreadEvictingPages",
+}
+
 var DbDataStats = map[string]string{
 	"collections":  "Collections",
 	"objects":      "Objects",
@@ -121,13 +136,11 @@ func (d *MongodbData) AddDefaultStats() {
 			floatVal, _ := strconv.ParseFloat(percentVal, 64)
 			d.add(key, floatVal)
 		}
+		d.addStat(statLine, WiredTigerExtStats)
 	}
 }
 
-func (d *MongodbData) addStat(
-	statLine reflect.Value,
-	stats map[string]string,
-) {
+func (d *MongodbData) addStat(statLine reflect.Value, stats map[string]string) {
 	for key, value := range stats {
 		val := statLine.FieldByName(value).Interface()
 		d.add(key, val)

plugins/inputs/mongodb/mongodb_data_test.go

@@ -70,9 +70,21 @@ func TestAddReplStats(t *testing.T) {
 func TestAddWiredTigerStats(t *testing.T) {
 	d := NewMongodbData(
 		&StatLine{
-			StorageEngine:     "wiredTiger",
-			CacheDirtyPercent: 0,
-			CacheUsedPercent:  0,
+			StorageEngine:             "wiredTiger",
+			CacheDirtyPercent:         0,
+			CacheUsedPercent:          0,
+			TrackedDirtyBytes:         0,
+			CurrentCachedBytes:        0,
+			MaxBytesConfigured:        0,
+			AppThreadsPageReadCount:   0,
+			AppThreadsPageReadTime:    0,
+			AppThreadsPageWriteCount:  0,
+			BytesWrittenFrom:          0,
+			BytesReadInto:             0,
+			PagesEvictedByAppThread:   0,
+			PagesQueuedForEviction:    0,
+			ServerEvictingPages:       0,
+			WorkerThreadEvictingPages: 0,
 		},
 		tags,
 	)

plugins/inputs/mongodb/mongostat.go

@@ -127,9 +127,19 @@ type ConcurrentTransStats struct {
 
 // CacheStats stores cache statistics for WiredTiger.
 type CacheStats struct {
-	TrackedDirtyBytes  int64 `bson:"tracked dirty bytes in the cache"`
-	CurrentCachedBytes int64 `bson:"bytes currently in the cache"`
-	MaxBytesConfigured int64 `bson:"maximum bytes configured"`
+	TrackedDirtyBytes         int64 `bson:"tracked dirty bytes in the cache"`
+	CurrentCachedBytes        int64 `bson:"bytes currently in the cache"`
+	MaxBytesConfigured        int64 `bson:"maximum bytes configured"`
+	AppThreadsPageReadCount   int64 `bson:"application threads page read from disk to cache count"`
+	AppThreadsPageReadTime    int64 `bson:"application threads page read from disk to cache time (usecs)"`
+	AppThreadsPageWriteCount  int64 `bson:"application threads page write from cache to disk count"`
+	AppThreadsPageWriteTime   int64 `bson:"application threads page write from cache to disk time (usecs)"`
+	BytesWrittenFrom          int64 `bson:"bytes written from cache"`
+	BytesReadInto             int64 `bson:"bytes read into cache"`
+	PagesEvictedByAppThread   int64 `bson:"pages evicted by application threads"`
+	PagesQueuedForEviction    int64 `bson:"pages queued for eviction"`
+	ServerEvictingPages       int64 `bson:"eviction server evicting pages"`
+	WorkerThreadEvictingPages int64 `bson:"eviction worker thread evicting pages"`
 }
 
 // TransactionStats stores transaction checkpoints in WiredTiger.
@@ -406,6 +416,20 @@ type StatLine struct {
 	CacheDirtyPercent float64
 	CacheUsedPercent  float64
 
+	// Cache ultilization extended (wiredtiger only)
+	TrackedDirtyBytes         int64
+	CurrentCachedBytes        int64
+	MaxBytesConfigured        int64
+	AppThreadsPageReadCount   int64
+	AppThreadsPageReadTime    int64
+	AppThreadsPageWriteCount  int64
+	BytesWrittenFrom          int64
+	BytesReadInto             int64
+	PagesEvictedByAppThread   int64
+	PagesQueuedForEviction    int64
+	ServerEvictingPages       int64
+	WorkerThreadEvictingPages int64
+
 	// Replicated Opcounter fields
 	InsertR, QueryR, UpdateR, DeleteR, GetMoreR, CommandR int64
 	ReplLag                                               int64
@@ -534,6 +558,19 @@ func NewStatLine(oldMongo, newMongo MongoStatus, key string, all bool, sampleSec
 		returnVal.Flushes = newStat.WiredTiger.Transaction.TransCheckpoints - oldStat.WiredTiger.Transaction.TransCheckpoints
 		returnVal.CacheDirtyPercent = float64(newStat.WiredTiger.Cache.TrackedDirtyBytes) / float64(newStat.WiredTiger.Cache.MaxBytesConfigured)
 		returnVal.CacheUsedPercent = float64(newStat.WiredTiger.Cache.CurrentCachedBytes) / float64(newStat.WiredTiger.Cache.MaxBytesConfigured)
+
+		returnVal.TrackedDirtyBytes = newStat.WiredTiger.Cache.TrackedDirtyBytes
+		returnVal.CurrentCachedBytes = newStat.WiredTiger.Cache.CurrentCachedBytes
+		returnVal.MaxBytesConfigured = newStat.WiredTiger.Cache.MaxBytesConfigured
+		returnVal.AppThreadsPageReadCount = newStat.WiredTiger.Cache.AppThreadsPageReadCount
+		returnVal.AppThreadsPageReadTime = newStat.WiredTiger.Cache.AppThreadsPageReadTime
+		returnVal.AppThreadsPageWriteCount = newStat.WiredTiger.Cache.AppThreadsPageWriteCount
+		returnVal.BytesWrittenFrom = newStat.WiredTiger.Cache.BytesWrittenFrom
+		returnVal.BytesReadInto = newStat.WiredTiger.Cache.BytesReadInto
+		returnVal.PagesEvictedByAppThread = newStat.WiredTiger.Cache.PagesEvictedByAppThread
+		returnVal.PagesQueuedForEviction = newStat.WiredTiger.Cache.PagesQueuedForEviction
+		returnVal.ServerEvictingPages = newStat.WiredTiger.Cache.ServerEvictingPages
+		returnVal.WorkerThreadEvictingPages = newStat.WiredTiger.Cache.WorkerThreadEvictingPages
 	} else if newStat.BackgroundFlushing != nil && oldStat.BackgroundFlushing != nil {
 		returnVal.Flushes = newStat.BackgroundFlushing.Flushes - oldStat.BackgroundFlushing.Flushes
 	}