diff --git a/internal/net/gphttp/accesslog/access_logger.go b/internal/net/gphttp/accesslog/access_logger.go
index 3f56fa2b..34e752e8 100644
--- a/internal/net/gphttp/accesslog/access_logger.go
+++ b/internal/net/gphttp/accesslog/access_logger.go
@@ -11,6 +11,7 @@ import (
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/logging"
 	"github.com/yusing/go-proxy/internal/task"
+	"github.com/yusing/go-proxy/internal/utils/synk"
 )
 
 type (
@@ -20,7 +21,7 @@ type (
 		io       AccessLogIO
 		buffered *bufio.Writer
 
-		lineBufPool sync.Pool // buffer pool for formatting a single log line
+		lineBufPool *synk.BytesPool // buffer pool for formatting a single log line
 		Formatter
 	}
 
@@ -78,7 +79,7 @@ func NewAccessLoggerWithIO(parent task.Parent, io AccessLogIO, cfg *Config) *Acc
 		cfg.BufferSize = 4096
 	}
 	l := &AccessLogger{
-		task:     parent.Subtask("accesslog"),
+		task:     parent.Subtask("accesslog."+io.Name(), true),
 		cfg:      cfg,
 		io:       io,
 		buffered: bufio.NewWriterSize(io, cfg.BufferSize),
@@ -96,9 +97,7 @@ func NewAccessLoggerWithIO(parent task.Parent, io AccessLogIO, cfg *Config) *Acc
 		panic("invalid access log format")
 	}
 
-	l.lineBufPool.New = func() any {
-		return bytes.NewBuffer(make([]byte, 0, 1024))
-	}
+	l.lineBufPool = synk.NewBytesPool(1024, synk.DefaultMaxBytes)
 	go l.start()
 	return l
 }
@@ -118,12 +117,11 @@ func (l *AccessLogger) Log(req *http.Request, res *http.Response) {
 		return
 	}
 
-	line := l.lineBufPool.Get().(*bytes.Buffer)
-	line.Reset()
+	line := l.lineBufPool.Get()
 	defer l.lineBufPool.Put(line)
-	l.Formatter.Format(line, req, res)
-	line.WriteRune('\n')
-	l.write(line.Bytes())
+	l.Formatter.Format(bytes.NewBuffer(line), req, res)
+	line = append(line, '\n')
+	l.write(line)
 }
 
 func (l *AccessLogger) LogError(req *http.Request, err error) {
diff --git a/internal/utils/io.go b/internal/utils/io.go
index 0a25938e..5b5b8e3e 100644
--- a/internal/utils/io.go
+++ b/internal/utils/io.go
@@ -9,6 +9,7 @@ import (
 	"syscall"
 
 	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/utils/synk"
 )
 
 // TODO: move to "utils/io".
@@ -117,24 +118,21 @@ func getHttpFlusher(dst io.Writer) httpFlusher {
 	return nil
 }
 
-const (
-	copyBufSize = 32 * 1024
-)
+const copyBufSize = 32 * 1024
 
-var copyBufPool = sync.Pool{
-	New: func() any {
-		return make([]byte, copyBufSize)
-	},
-}
+var copyBufPool = synk.NewBytesPool(copyBufSize, synk.DefaultMaxBytes)
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // This is a copy of io.Copy with context and HTTP flusher handling
 // Author: yusing <yusing@6uo.me>.
 func CopyClose(dst *ContextWriter, src *ContextReader) (err error) {
-	var buf []byte
+	buf := copyBufPool.Get()
+	defer copyBufPool.Put(buf)
+
+	var size int
 	if l, ok := src.Reader.(*io.LimitedReader); ok {
-		size := copyBufSize
+		size = copyBufSize
 		if int64(size) > l.N {
 			if l.N < 1 {
 				size = 1
@@ -142,10 +140,8 @@ func CopyClose(dst *ContextWriter, src *ContextReader) (err error) {
 				size = int(l.N)
 			}
 		}
-		buf = make([]byte, 0, size)
 	} else {
-		buf = copyBufPool.Get().([]byte)
-		defer copyBufPool.Put(buf[:0])
+		size = cap(buf)
 	}
 	// close both as soon as one of them is done
 	wCloser, wCanClose := dst.Writer.(io.Closer)
@@ -179,7 +175,7 @@ func CopyClose(dst *ContextWriter, src *ContextReader) (err error) {
 	flusher := getHttpFlusher(dst.Writer)
 	canFlush := flusher != nil
 	for {
-		nr, er := src.Reader.Read(buf[:copyBufSize])
+		nr, er := src.Reader.Read(buf[:size])
 		if nr > 0 {
 			nw, ew := dst.Writer.Write(buf[0:nr])
 			if nw < 0 || nr < nw {
diff --git a/internal/utils/synk/pool.go b/internal/utils/synk/pool.go
new file mode 100644
index 00000000..2f1164be
--- /dev/null
+++ b/internal/utils/synk/pool.go
@@ -0,0 +1,42 @@
+package synk
+
+import "sync"
+
+type (
+	// Pool is a wrapper of sync.Pool that limits the size of the object.
+	Pool[T any] struct {
+		pool    sync.Pool
+		maxSize int
+	}
+	BytesPool = Pool[byte]
+)
+
+const (
+	DefaultInitBytes = 1024
+	DefaultMaxBytes  = 1024 * 1024
+)
+
+func NewPool[T any](initSize int, maxSize int) *Pool[T] {
+	return &Pool[T]{
+		pool: sync.Pool{
+			New: func() any {
+				return make([]T, 0, initSize)
+			},
+		},
+		maxSize: maxSize,
+	}
+}
+
+func NewBytesPool(initSize int, maxSize int) *BytesPool {
+	return NewPool[byte](initSize, maxSize)
+}
+
+func (p *Pool[T]) Get() []T {
+	return p.pool.Get().([]T)
+}
+
+func (p *Pool[T]) Put(b []T) {
+	if cap(b) <= p.maxSize {
+		p.pool.Put(b[:0])
+	}
+}
diff --git a/pkg/json/json.go b/pkg/json/json.go
index ba0bedf9..4927018e 100644
--- a/pkg/json/json.go
+++ b/pkg/json/json.go
@@ -2,9 +2,9 @@ package json
 
 import (
 	"reflect"
-	"sync"
 
 	"github.com/bytedance/sonic"
+	"github.com/yusing/go-proxy/internal/utils/synk"
 )
 
 type Marshaler interface {
@@ -38,8 +38,8 @@ var (
 //
 //   - It does not support maps other than string-keyed maps.
 func Marshal(v any) ([]byte, error) {
-	buf := newBytes()
-	defer putBytes(buf)
+	buf := bytesPool.Get()
+	defer bytesPool.Put(buf)
 	return cloneBytes(appendMarshal(reflect.ValueOf(v), buf)), nil
 }
 
@@ -47,21 +47,9 @@ func MarshalTo(v any, buf []byte) []byte {
 	return appendMarshal(reflect.ValueOf(v), buf)
 }
 
-const bufSize = 8192
+const initBufSize = 4096
 
-var bytesPool = sync.Pool{
-	New: func() any {
-		return make([]byte, 0, bufSize)
-	},
-}
-
-func newBytes() []byte {
-	return bytesPool.Get().([]byte)
-}
-
-func putBytes(buf []byte) {
-	bytesPool.Put(buf[:0])
-}
+var bytesPool = synk.NewBytesPool(initBufSize, synk.DefaultMaxBytes)
 
 func cloneBytes(buf []byte) (res []byte) {
 	return append(res, buf...)