diff --git a/opensearch/client.go b/opensearch/client.go
index 910775a..c2ba28b 100644
--- a/opensearch/client.go
+++ b/opensearch/client.go
@@ -32,7 +32,6 @@ type Client struct {
 	indexTemplatePattern string
 	bulkHeader           http.Header
 	singleHeader         http.Header
-	sendingCount         int32
 	bulkChan             chan *LogDocument
 }
 
@@ -76,28 +75,40 @@ func (c *Client) SendBulk(ds map[string]*LogDocument) {
 }
 
 type stringSliceReader struct {
-	src [][]byte
+	src  [][]byte
+	sent [][]byte
 }
 
 func (b *stringSliceReader) Read(p []byte) (n int, err error) {
+	n = 0
+	err = nil
+
 	for len(b.src) > 0 {
 		sbt := b.src[0]
-		if len(p) < len(sbt) {
-			b.src[0] = sbt[len(p):]
-			sbt = sbt[:len(p)]
-			copy(p, sbt)
-			return n + len(sbt), nil
+		copied := copy(p, sbt)
+		n += copied
+		b.sent = append(b.sent, sbt[:copied])
+
+		if copied < len(sbt) {
+			b.src[0] = sbt[copied:]
+			return
 		}
 
-		copy(p, sbt)
-		n += len(sbt)
-		p = p[len(sbt):]
+		p = p[copied:]
 		b.src = b.src[1:]
 	}
+
 	err = io.EOF
 	return
 }
 
+func (b *stringSliceReader) printSent() {
+	for _, r := range b.sent {
+		fmt.Print(string(r))
+	}
+	fmt.Print("\n")
+}
+
 func (c *Client) sendLoop(ctx context.Context) {
 	defer func() {
 		r := recover()
@@ -145,11 +156,9 @@ func (c *Client) sendLoop(ctx context.Context) {
 			resp, err := c.Do(context.Background(), req, nil)
 			if err != nil {
 				if netoperr, ok := err.(*net.OpError); ok && netoperr.Op == "dial" {
-					// 접속 안됨. 파일로 남기고 끝
+					// 접속 안됨. 재시도 안함
 					logger.Println("log send bulk failed. no retry :", err)
-					for _, e := range sending {
-						logger.Println(string(e))
-					}
+					reader.printSent()
 				} else {
 					// 재시도
 					logger.Println("log send bulk failed. retry :", err)