Expose BulkIndexer total flushed bytes metric (#914) (#931)

Co-authored-by: Aurèle Oulès <aurele@oules.com>

Author: Anaethelion

esutil/bulk_indexer.go

@@ -86,14 +86,15 @@ type BulkIndexerConfig struct {
 
 // BulkIndexerStats represents the indexer statistics.
 type BulkIndexerStats struct {
-	NumAdded    uint64
-	NumFlushed  uint64
-	NumFailed   uint64
-	NumIndexed  uint64
-	NumCreated  uint64
-	NumUpdated  uint64
-	NumDeleted  uint64
-	NumRequests uint64
+	NumAdded     uint64
+	NumFlushed   uint64
+	NumFailed    uint64
+	NumIndexed   uint64
+	NumCreated   uint64
+	NumUpdated   uint64
+	NumDeleted   uint64
+	NumRequests  uint64
+	FlushedBytes uint64
 }
 
 // BulkIndexerItem represents an indexer item.
@@ -266,14 +267,15 @@ type bulkIndexer struct {
 }
 
 type bulkIndexerStats struct {
-	numAdded    uint64
-	numFlushed  uint64
-	numFailed   uint64
-	numIndexed  uint64
-	numCreated  uint64
-	numUpdated  uint64
-	numDeleted  uint64
-	numRequests uint64
+	numAdded     uint64
+	numFlushed   uint64
+	numFailed    uint64
+	numIndexed   uint64
+	numCreated   uint64
+	numUpdated   uint64
+	numDeleted   uint64
+	numRequests  uint64
+	flushedBytes uint64
 }
 
 // NewBulkIndexer creates a new bulk indexer.
@@ -354,14 +356,15 @@ func (bi *bulkIndexer) Close(ctx context.Context) error {
 // Stats returns indexer statistics.
 func (bi *bulkIndexer) Stats() BulkIndexerStats {
 	return BulkIndexerStats{
-		NumAdded:    atomic.LoadUint64(&bi.stats.numAdded),
-		NumFlushed:  atomic.LoadUint64(&bi.stats.numFlushed),
-		NumFailed:   atomic.LoadUint64(&bi.stats.numFailed),
-		NumIndexed:  atomic.LoadUint64(&bi.stats.numIndexed),
-		NumCreated:  atomic.LoadUint64(&bi.stats.numCreated),
-		NumUpdated:  atomic.LoadUint64(&bi.stats.numUpdated),
-		NumDeleted:  atomic.LoadUint64(&bi.stats.numDeleted),
-		NumRequests: atomic.LoadUint64(&bi.stats.numRequests),
+		NumAdded:     atomic.LoadUint64(&bi.stats.numAdded),
+		NumFlushed:   atomic.LoadUint64(&bi.stats.numFlushed),
+		NumFailed:    atomic.LoadUint64(&bi.stats.numFailed),
+		NumIndexed:   atomic.LoadUint64(&bi.stats.numIndexed),
+		NumCreated:   atomic.LoadUint64(&bi.stats.numCreated),
+		NumUpdated:   atomic.LoadUint64(&bi.stats.numUpdated),
+		NumDeleted:   atomic.LoadUint64(&bi.stats.numDeleted),
+		NumRequests:  atomic.LoadUint64(&bi.stats.numRequests),
+		FlushedBytes: atomic.LoadUint64(&bi.stats.flushedBytes),
 	}
 }
 
@@ -508,7 +511,9 @@ func (w *worker) flushBuffer(ctx context.Context) error {
 		defer func() { w.bi.config.OnFlushEnd(ctx) }()
 	}
 
-	if w.buf.Len() < 1 {
+	bufLen := w.buf.Len()
+
+	if bufLen < 1 {
 		if w.bi.config.DebugLogger != nil {
 			w.bi.config.DebugLogger.Printf("[worker-%03d] Flush: Buffer empty\n", w.id)
 		}
@@ -631,6 +636,8 @@ func (w *worker) flushBuffer(ctx context.Context) error {
 		}
 	}
 
+	atomic.AddUint64(&w.bi.stats.flushedBytes, uint64(bufLen))
+
 	return err
 }