diff --git a/server/src/core/core.go b/server/src/core/core.go
index 82bfac3..a0e7000 100644
--- a/server/src/core/core.go
+++ b/server/src/core/core.go
@@ -4,8 +4,9 @@ import "sync"
 
 // Core ...
 type Core struct {
-	pool map[[16]byte]*row
-	mux  sync.Mutex
+	serial int
+	pool   map[[16]byte]*row
+	mux    sync.Mutex
 }
 
 // NewCore ...
diff --git a/server/src/core/fetch.go b/server/src/core/fetch.go
index ea0cac3..3524835 100644
--- a/server/src/core/fetch.go
+++ b/server/src/core/fetch.go
@@ -11,14 +11,14 @@ import (
 	"time"
 )
 
-func (pr *row) fetchRemote() (ab []byte, ok bool, err error) {
+func (pr *row) fetchRemote() (ab []byte, err error) {
 
 	r := pr.req
 	b := pr.log
 
 	u, err := url.Parse(config.OpenAIBase + r.Url)
 	if err != nil {
-		return nil, false, err
+		return nil, err
 	}
 	// zj.J(`real url`, u.String())
 
@@ -39,9 +39,7 @@ func (pr *row) fetchRemote() (ab []byte, ok bool, err error) {
 		return
 	}
 
-	if rsp.StatusCode >= 200 || rsp.StatusCode < 300 {
-		ok = true
-	} else {
+	if rsp.StatusCode < 200 || rsp.StatusCode >= 300 {
 		err = fmt.Errorf(`status code fail: %d`, rsp.StatusCode)
 		b.WriteString(err.Error())
 	}
diff --git a/server/src/core/pool.go b/server/src/core/pool.go
index 6c3eaa7..81d0944 100644
--- a/server/src/core/pool.go
+++ b/server/src/core/pool.go
@@ -19,11 +19,14 @@ func (c *Core) add(req *pb.Req, hr *http.Request) (pr *row, cached bool) {
 		return
 	}
 
+	c.serial++
 	pr = &row{
-		hr:   hr,
-		hash: hash,
-		req:  req,
-		t:    time.Now(),
+		serial: c.serial,
+		hr:     hr,
+		hash:   hash,
+		req:    req,
+		t:      time.Now(),
+		core:   c,
 	}
 	pr.mux.Lock()
 	go pr.run()
@@ -31,3 +34,12 @@ func (c *Core) add(req *pb.Req, hr *http.Request) (pr *row, cached bool) {
 	c.mux.Unlock()
 	return
 }
+
+func (c *Core) delete(r *row) {
+	c.mux.Lock()
+	pr, ok := c.pool[r.hash]
+	if ok && pr == r {
+		delete(c.pool, r.hash)
+	}
+	c.mux.Unlock()
+}
diff --git a/server/src/core/row.go b/server/src/core/row.go
index 62ded2a..2037c79 100644
--- a/server/src/core/row.go
+++ b/server/src/core/row.go
@@ -11,15 +11,22 @@ import (
 )
 
 type row struct {
-	hash [16]byte
-	hr   *http.Request
-	req  *pb.Req
-	rsp  []byte
-	err  error
-	done bool
-	t    time.Time
-	mux  sync.RWMutex
-	log  *bytes.Buffer
+	serial int
+	hash   [16]byte
+	hr     *http.Request
+	req    *pb.Req
+	rsp    []byte
+	err    error
+	done   bool
+	t      time.Time
+	mux    sync.RWMutex
+	log    *bytes.Buffer
+	core   *Core
+}
+
+func (pr *row) suicide() {
+	pr.core.delete(pr)
+	pr.core = nil
 }
 
 func (pr *row) run() {
@@ -33,20 +40,20 @@ func (pr *row) run() {
 		// return
 	}
 
-	var ok bool
-	pr.rsp, ok, pr.err = pr.fetchRemote()
-	if pr.err == nil && ok {
-		// pr.failLog.Reset()
-		go writeFailLog(pr.hash, pr.log.Bytes())
-	} else {
-		go writeFailLog(pr.hash, pr.log.Bytes())
-	}
-
-	go pr.saveFile()
-	// go pr.metrics()
-
+	pr.rsp, pr.err = pr.fetchRemote()
 	pr.done = true
 	pr.mux.Unlock()
+
+	// go pr.metrics()
+
+	if pr.err == nil {
+		// pr.failLog.Reset()
+		// go writeFailLog(pr.hash, pr.log.Bytes())
+		go pr.saveFile()
+	} else {
+		go writeFailLog(pr.hash, pr.log.Bytes())
+		go pr.suicide()
+	}
 }
 
 func (pr *row) wait() {