diff --git a/storage/clickhousespanstore/pool.go b/storage/clickhousespanstore/pool.go
index 710a6bc..21d5c95 100644
--- a/storage/clickhousespanstore/pool.go
+++ b/storage/clickhousespanstore/pool.go
@@ -60,11 +60,14 @@ func (pool *WriteWorkerPool) Work() {
 	finish := false
 	nextWorkerID := int32(1)
 	pendingSpanCount := 0
+
+	pool.done.Add(1)
+	defer pool.done.Done()
+
 	for {
 		// Initialize to zero, or update value from previous loop
 		numPendingSpans.Set(float64(pendingSpanCount))
 
-		pool.done.Add(1)
 		select {
 		case batch := <-pool.batches:
 			batchSize := len(batch)
@@ -103,7 +106,6 @@ func (pool *WriteWorkerPool) Work() {
 			pool.workers.CloseWorkers()
 			finish = true
 		}
-		pool.done.Done()
 
 		if finish {
 			break
diff --git a/storage/clickhousespanstore/writer.go b/storage/clickhousespanstore/writer.go
index d68a36e..931242c 100644
--- a/storage/clickhousespanstore/writer.go
+++ b/storage/clickhousespanstore/writer.go
@@ -88,13 +88,32 @@ func (w *SpanWriter) registerMetrics() {
 func (w *SpanWriter) backgroundWriter(maxSpanCount int) {
 	pool := NewWorkerPool(&w.workerParams, maxSpanCount)
 	go pool.Work()
-	batch := make([]*model.Span, 0, w.size)
 
+	batch := make([]*model.Span, 0, w.size)
 	timer := time.After(w.workerParams.delay)
 	last := time.Now()
 
+	finishSpan := func() {
+		for len(w.spans) > 0 {
+			select {
+			case span := <-w.spans:
+				batch = append(batch, span)
+				if len(batch) >= cap(batch) {
+					pool.WriteBatch(batch)
+				}
+			default:
+			}
+		}
+		if len(batch) > 0 {
+			pool.WriteBatch(batch)
+		}
+		pool.Close()
+	}
+
+	w.done.Add(1)
+	defer w.done.Done()
+
 	for {
-		w.done.Add(1)
 
 		flush := false
 		finish := false
@@ -128,11 +147,7 @@ func (w *SpanWriter) backgroundWriter(maxSpanCount int) {
 		}
 
 		if finish {
-			pool.Close()
-		}
-		w.done.Done()
-
-		if finish {
+			finishSpan()
 			break
 		}
 	}