func newCheckPerfCommand(cmd *cobra.Command, args []string) {
	var checkPerfAlias = map[string]string{
		"s": "s", "small": "s",
		"m": "m", "medium": "m",
		"l": "l", "large": "l",
		"xl": "xl", "xLarge": "xl",
	}

	model, ok := checkPerfAlias[checkPerfLoad]
	if !ok {
		ExitWithError(ExitBadFeature, fmt.Errorf("unknown load option %v", checkPerfLoad))
	}
	cfg := checkPerfCfgMap[model]

	requests := make(chan v3.Op, cfg.clients)
	limit := rate.NewLimiter(rate.Limit(cfg.limit), 1)

	cc := clientConfigFromCmd(cmd)
	clients := make([]*v3.Client, cfg.clients)
	for i := 0; i < cfg.clients; i++ {
		clients[i] = cc.mustClient()
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(cfg.duration)*time.Second)
	resp, err := clients[0].Get(ctx, checkPerfPrefix, v3.WithPrefix(), v3.WithLimit(1))
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}
	if len(resp.Kvs) > 0 {
		ExitWithError(ExitInvalidInput, fmt.Errorf("prefix %q has keys. Delete with etcdctl del --prefix %s first", checkPerfPrefix, checkPerfPrefix))
	}

	ksize, vsize := 256, 1024
	k, v := make([]byte, ksize), string(make([]byte, vsize))

	bar := pb.New(cfg.duration)
	bar.Format("Bom !")
	bar.Start()

	r := report.NewReport("%4.4f")
	var wg sync.WaitGroup

	wg.Add(len(clients))
	for i := range clients {
		go func(c *v3.Client) {
			defer wg.Done()
			for op := range requests {
				st := time.Now()
				_, derr := c.Do(context.Background(), op)
				r.Results() <- report.Result{Err: derr, Start: st, End: time.Now()}
			}
		}(clients[i])
	}

	go func() {
		cctx, ccancel := context.WithTimeout(context.Background(), time.Duration(cfg.duration)*time.Second)
		defer ccancel()
		for limit.Wait(cctx) == nil {
			binary.PutVarint(k, rand.Int63n(math.MaxInt64))
			requests <- v3.OpPut(checkPerfPrefix+string(k), v)
		}
		close(requests)
	}()

	go func() {
		for i := 0; i < cfg.duration; i++ {
			time.Sleep(time.Second)
			bar.Add(1)
		}
		bar.Finish()
	}()

	sc := r.Stats()
	wg.Wait()
	close(r.Results())

	s := <-sc

	ctx, cancel = context.WithTimeout(context.Background(), 30*time.Second)
	dresp, err := clients[0].Delete(ctx, checkPerfPrefix, v3.WithPrefix())
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}

	if autoCompact {
		compact(clients[0], dresp.Header.Revision)
	}

	if autoDefrag {
		for _, ep := range clients[0].Endpoints() {
			defrag(clients[0], ep)
		}
	}

	ok = true
	if len(s.ErrorDist) != 0 {
		fmt.Println("FAIL: too many errors")
		for k, v := range s.ErrorDist {
			fmt.Printf("FAIL: ERROR(%v) -> %d\n", k, v)
		}
		ok = false
	}

	if s.RPS/float64(cfg.limit) <= 0.9 {
		fmt.Printf("FAIL: Throughput too low: %d writes/s\n", int(s.RPS)+1)
		ok = false
	} else {
		fmt.Printf("PASS: Throughput is %d writes/s\n", int(s.RPS)+1)
	}
	if s.Slowest > 0.5 { // slowest request > 500ms
		fmt.Printf("Slowest request took too long: %fs\n", s.Slowest)
		ok = false
	} else {
		fmt.Printf("PASS: Slowest request took %fs\n", s.Slowest)
	}
	if s.Stddev > 0.1 { // stddev > 100ms
		fmt.Printf("Stddev too high: %fs\n", s.Stddev)
		ok = false
	} else {
		fmt.Printf("PASS: Stddev is %fs\n", s.Stddev)
	}

	if ok {
		fmt.Println("PASS")
	} else {
		fmt.Println("FAIL")
		os.Exit(ExitError)
	}
}
func newCheckPerfCommand(cmd *cobra.Command, args []string) {
	var checkPerfAlias = map[string]string{
		"s": "s", "small": "s",
		"m": "m", "medium": "m",
		"l": "l", "large": "l",
		"xl": "xl", "xLarge": "xl",
	}

	model, ok := checkPerfAlias[checkPerfLoad]
	if !ok {
		ExitWithError(ExitBadFeature, fmt.Errorf("unknown load option %v", checkPerfLoad))
	}
	cfg := checkPerfCfgMap[model]

	requests := make(chan v3.Op, cfg.clients)
	limit := rate.NewLimiter(rate.Limit(cfg.limit), 1)

	cc := clientConfigFromCmd(cmd)
	clients := make([]*v3.Client, cfg.clients)
	for i := 0; i < cfg.clients; i++ {
		clients[i] = cc.mustClient()
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(cfg.duration)*time.Second)
	resp, err := clients[0].Get(ctx, checkPerfPrefix, v3.WithPrefix(), v3.WithLimit(1))
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}
	if len(resp.Kvs) > 0 {
		ExitWithError(ExitInvalidInput, fmt.Errorf("prefix %q has keys. Delete with etcdctl del --prefix %s first", checkPerfPrefix, checkPerfPrefix))
	}

	ksize, vsize := 256, 1024
	k, v := make([]byte, ksize), string(make([]byte, vsize))

	bar := pb.New(cfg.duration)
	bar.Format("Bom !")
	bar.Start()

	r := report.NewReport("%4.4f")
	var wg sync.WaitGroup

	wg.Add(len(clients))
	for i := range clients {
		go func(c *v3.Client) {
			defer wg.Done()
			for op := range requests {
				st := time.Now()
				_, derr := c.Do(context.Background(), op)
				r.Results() <- report.Result{Err: derr, Start: st, End: time.Now()}
			}
		}(clients[i])
	}

	go func() {
		cctx, ccancel := context.WithTimeout(context.Background(), time.Duration(cfg.duration)*time.Second)
		defer ccancel()
		for limit.Wait(cctx) == nil {
			binary.PutVarint(k, rand.Int63n(math.MaxInt64))
			requests <- v3.OpPut(checkPerfPrefix+string(k), v)
		}
		close(requests)
	}()

	go func() {
		for i := 0; i < cfg.duration; i++ {
			time.Sleep(time.Second)
			bar.Add(1)
		}
		bar.Finish()
	}()

	sc := r.Stats()
	wg.Wait()
	close(r.Results())

	s := <-sc

	ctx, cancel = context.WithTimeout(context.Background(), 30*time.Second)
	dresp, err := clients[0].Delete(ctx, checkPerfPrefix, v3.WithPrefix())
	cancel()
	if err != nil {
		ExitWithError(ExitError, err)
	}

	if autoCompact {
		compact(clients[0], dresp.Header.Revision)
	}

	if autoDefrag {
		for _, ep := range clients[0].Endpoints() {
			defrag(clients[0], ep)
		}
	}

	ok = true
	if len(s.ErrorDist) != 0 {
		fmt.Println("FAIL: too many errors")
		for k, v := range s.ErrorDist {
			fmt.Printf("FAIL: ERROR(%v) -> %d\n", k, v)
		}
		ok = false
	}

	if s.RPS/float64(cfg.limit) <= 0.9 {
		fmt.Printf("FAIL: Throughput too low: %d writes/s\n", int(s.RPS)+1)
		ok = false
	} else {
		fmt.Printf("PASS: Throughput is %d writes/s\n", int(s.RPS)+1)
	}
	if s.Slowest > 0.5 { // slowest request > 500ms
		fmt.Printf("Slowest request took too long: %fs\n", s.Slowest)
		ok = false
	} else {
		fmt.Printf("PASS: Slowest request took %fs\n", s.Slowest)
	}
	if s.Stddev > 0.1 { // stddev > 100ms
		fmt.Printf("Stddev too high: %fs\n", s.Stddev)
		ok = false
	} else {
		fmt.Printf("PASS: Stddev is %fs\n", s.Stddev)
	}

	if ok {
		fmt.Println("PASS")
	} else {
		fmt.Println("FAIL")
		os.Exit(ExitError)
	}
}
// newCheckPerfCommand executes the "check perf" command.