cmd: add pd-bench application

Used to benchmark GetTS performance.

Makefile

@@ -28,6 +28,7 @@ build:
 	rm -rf vendor && ln -s _vendor/vendor vendor
 	$(GO) build -ldflags '$(LDFLAGS)' -o bin/pd-server cmd/pd-server/main.go
 	$(GO) build  -o bin/pd-ctl cmd/pd-ctl/main.go
+	$(GO) build  -o bin/pd-bench cmd/pd-bench/main.go
 	rm -rf vendor
 
 install:

cmd/pd-bench/main.go

@@ -0,0 +1,94 @@
+// Copyright 2017 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"sync"
+	"time"
+
+	"github.com/pingcap/pd/pd-client"
+)
+
+var (
+	pdAddrs     = flag.String("pd", "127.0.0.1:2379", "pd address")
+	concurrency = flag.Int("C", 100, "concurrency")
+	num         = flag.Int("N", 1000, "number of request per request worker")
+	sleepFlag   = flag.String("sleep", "1ms", "sleep time after a request, used to adjust pressure")
+	sleep       = time.Millisecond
+)
+
+func main() {
+	flag.Parse()
+	pdCli, err := pd.NewClient([]string{*pdAddrs})
+	if err != nil {
+		log.Fatal(err)
+	}
+	// To avoid the first time high latency.
+	_, _, err = pdCli.GetTS()
+	if err != nil {
+		log.Fatal(err)
+	}
+	sleep, err = time.ParseDuration(*sleepFlag)
+	if err != nil {
+		log.Fatal(err)
+	}
+	wg := new(sync.WaitGroup)
+	wg.Add(*concurrency)
+	for i := 0; i < *concurrency; i++ {
+		go reqWorker(pdCli, wg)
+	}
+	wg.Wait()
+	pdCli.Close()
+}
+
+func reqWorker(pdCli pd.Client, wg *sync.WaitGroup) {
+	var maxDur time.Duration
+	var maxidx int
+	var minDur = time.Second
+	var (
+		milliCnt     int
+		twoMilliCnt  int
+		fiveMilliCnt int
+	)
+	for i := 0; i < *num; i++ {
+		start := time.Now()
+		_, _, err := pdCli.GetTS()
+		if err != nil {
+			log.Fatal(err)
+		}
+		dur := time.Since(start)
+		if dur > maxDur {
+			maxDur = dur
+			maxidx = i
+		}
+		if dur < minDur {
+			minDur = dur
+		}
+		if dur > time.Millisecond {
+			milliCnt++
+		}
+		if dur > time.Millisecond*2 {
+			twoMilliCnt++
+		}
+		if dur > time.Millisecond*5 {
+			fiveMilliCnt++
+		}
+		time.Sleep(sleep)
+	}
+	fmt.Printf("max:(%v,%d), min:%v, num:%d, >1ms = %d, >2ms = %d, >5ms = %d\n", maxDur, maxidx, minDur, *num, milliCnt, twoMilliCnt, fiveMilliCnt)
+	wg.Done()
+}