diff --git a/internal/io/dataway/body.go b/internal/io/dataway/body.go
index 8f9b588d08..59844f3409 100644
--- a/internal/io/dataway/body.go
+++ b/internal/io/dataway/body.go
@@ -45,8 +45,7 @@ type body struct {
 
 	selfBuffer, // buffer that belongs to itself, and we should not drop it when putback
 	gzon int8
-	from      walFrom
-	checkSize bool
+	from walFrom
 }
 
 func (b *body) reset() {
@@ -109,18 +108,16 @@ func (b *body) loadCache(data []byte) error {
 }
 
 func (b *body) dump() ([]byte, error) {
-	if b.checkSize { // checkSize will not set on production, just for testing cases.
-		// NOTE: check required size before marshal, extra Size() call may cause a bit CPU time.
-		if s := b.CacheData.Size(); s > len(b.marshalBuf) {
-			return nil, fmt.Errorf("too small(%d) marshal buffer, need %d", len(b.marshalBuf), s)
-		}
-	}
-
-	// MarshalTo() all call Size() within itself.
-	if n, err := b.CacheData.MarshalTo(b.marshalBuf); err != nil {
-		return nil, fmt.Errorf("MarshalTo: %w", err)
+	// NOTE: check required size before marshal, extra Size() call may cause a bit CPU time.
+	if s := b.CacheData.Size(); s > len(b.marshalBuf) {
+		return nil, fmt.Errorf("too small(%d) marshal buffer, need %d", len(b.marshalBuf), s)
 	} else {
-		return b.marshalBuf[:n], nil
+		// MarshalTo() all call Size() within itself.
+		if n, err := b.CacheData.MarshalToSizedBuffer(b.marshalBuf[:s]); err != nil {
+			return nil, fmt.Errorf("MarshalTo: %w", err)
+		} else {
+			return b.marshalBuf[:n], nil
+		}
 	}
 }
 
@@ -245,11 +242,15 @@ func (w *writer) buildPointsBody() error {
 
 		encodeBytes, ok := enc.Next(b.sendBuf)
 		if !ok {
+			defer putBody(b)
+
 			if err := enc.LastErr(); err != nil {
 				l.Errorf("encode: %s, cat: %s, total points: %d, current part: %d, body cap: %d",
 					err.Error(), b.cat().Alias(), len(w.points), parts, cap(b.sendBuf))
 				return err
 			}
+
+			l.Debugf("last body: %s", b)
 			break
 		}
 
diff --git a/internal/io/dataway/body_test.go b/internal/io/dataway/body_test.go
index 86e92faa22..95f8214aef 100644
--- a/internal/io/dataway/body_test.go
+++ b/internal/io/dataway/body_test.go
@@ -555,7 +555,6 @@ func TestPBMarshalSize(t *T.T) {
 		b.CacheData.RawLen = int32(size)
 		b.Headers = append(b.Headers, &HTTPHeader{Key: HeaderXGlobalTags, Value: "looooooooooooooooooooooong value"})
 		b.DynURL = "https://openway.guance.com/v1/write/logging?token=tkn_11111111111111111111111"
-		b.checkSize = true // enable size checking, or panic
 
 		_, err := b.dump()
 		assert.Error(t, err)
diff --git a/internal/io/dataway/metrics.go b/internal/io/dataway/metrics.go
index d951da6be1..184423a73e 100644
--- a/internal/io/dataway/metrics.go
+++ b/internal/io/dataway/metrics.go
@@ -11,6 +11,7 @@ import (
 )
 
 var (
+	bodyCounterVec,
 	ptsCounterVec,
 	bytesCounterVec,
 	writeDropPointsCounterVec,
@@ -41,6 +42,7 @@ func APISumVec() *prometheus.SummaryVec {
 func Metrics() []prometheus.Collector {
 	return []prometheus.Collector{
 		walWorkerFlush,
+		bodyCounterVec,
 		ptsCounterVec,
 		walPointCounterVec,
 		bytesCounterVec,
@@ -59,6 +61,7 @@ func Metrics() []prometheus.Collector {
 
 func metricsReset() {
 	walWorkerFlush.Reset()
+	bodyCounterVec.Reset()
 	ptsCounterVec.Reset()
 	walPointCounterVec.Reset()
 	bytesCounterVec.Reset()
@@ -78,6 +81,7 @@ func metricsReset() {
 func doRegister() {
 	metrics.MustRegister(
 		walWorkerFlush,
+		bodyCounterVec,
 		ptsCounterVec,
 		walPointCounterVec,
 		bytesCounterVec,
@@ -216,6 +220,20 @@ func init() {
 		[]string{"category", "status"},
 	)
 
+	bodyCounterVec = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "datakit",
+			Subsystem: "io",
+			Name:      "dataway_body_total",
+			Help:      "Dataway total body",
+		},
+		[]string{
+			"from",
+			"op",
+			"type",
+		},
+	)
+
 	walPointCounterVec = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Namespace: "datakit",
diff --git a/internal/io/dataway/pool.go b/internal/io/dataway/pool.go
index 40c4fda667..610bb6d5e4 100644
--- a/internal/io/dataway/pool.go
+++ b/internal/io/dataway/pool.go
@@ -77,7 +77,10 @@ func getNewBufferBody(opts ...bodyOpt) *body {
 		b = &body{
 			selfBuffer: 1,
 		}
+
+		bodyCounterVec.WithLabelValues("malloc", "get", "new").Inc()
 	} else {
+		bodyCounterVec.WithLabelValues("pool", "get", "new").Inc()
 		b = x.(*body)
 	}
 
@@ -98,7 +101,10 @@ func getReuseBufferBody(opts ...bodyOpt) *body {
 		b = &body{
 			selfBuffer: 0,
 		}
+
+		bodyCounterVec.WithLabelValues("malloc", "get", "reuse").Inc()
 	} else {
+		bodyCounterVec.WithLabelValues("pool", "get", "reuse").Inc()
 		b = x.(*body)
 	}
 
@@ -119,8 +125,10 @@ func putBody(b *body) {
 
 		if b.selfBuffer == 1 {
 			newBufferBodyPool.Put(b)
+			bodyCounterVec.WithLabelValues("pool", "put", "new").Inc()
 		} else {
 			reuseBufferBodyPool.Put(b)
+			bodyCounterVec.WithLabelValues("pool", "put", "reuse").Inc()
 		}
 	}
 }