pprof工具使用

引入pprof

在代码库中引入log和net/http/pprof包，然后在main入口中起个端口监听

go func() {
    log.Println(http.ListenAndServe(":8888", nil))
}()

完整例子代码

package main

import (
    "encoding/binary"
    "fmt"
    "log"
    "net"
    "net/http"
    _ "net/http/pprof"
    "strconv"
    "strings"
    "time"
)

func main() {
    go func() {
        log.Println(http.ListenAndServe(":8888", nil))
    }()
    cidrs := []string{
        "1.2.3.4/8",
        "1.2.3.4/16",
        "1.2.3.4/24",
        "1.2.3.4/32",
        "1.2.3.4/1",
        "1.2.3.4/7",
        "1.2.3.4/22",
    }
    ipInt := [][2]int{
        {16777216, 33554431},
        {16908288, 16973823},
        {16909056, 16909311},
        {16909060, 16909060},
        {0, 2147483647},
        {0, 33554431},
        {16908288, 16909311},
    }
    for {
        for times := 0; times < 1000; times++ {
            for index := 0; index < len(cidrs); index++ {
                cidr := cidrs[index]
                targetStart, targetEnd := uint32(ipInt[index][0]), uint32(ipInt[index][1])
                start, end, _ := Cidr2range(cidr)
                if start != targetStart || end != targetEnd {
                    fmt.Printf("cidr:%s, targetStart:%d, targetEnd:%d, start:%d, end:%d\n", cidr, targetStart, targetEnd, start, end)
                }
            }
        }
        time.Sleep(time.Duration(1) * time.Second)
    }
}

// Ip2uint 将ip转换成unit32格式
func Ip2uint(ipStr string) uint32 {
    ip := net.ParseIP(ipStr)
    if ip == nil {
        return 0
    }
    ip = ip.To4()
    return binary.BigEndian.Uint32(ip)
}

// Cidr2range 将cidr格式的ipv4地址转换成[uint32 startIp, uint32 endIp]形式
func Cidr2range(cidr string) (uint32, uint32, error) {
    vipSegs := strings.Split(cidr, "/")
    ip := Ip2uint(vipSegs[0])

    var startIp uint32
    var endIp uint32

    if len(vipSegs) > 1 {
        mask, err := strconv.Atoi(vipSegs[1])
        if err != nil {
            return 0, 0, fmt.Errorf("mask type conversion failed")
        }
        startIp = ip & (((1 << uint32(mask)) - 1) << uint32(32-mask))
        endIp = ip | ((1 << uint32(32-mask)) - 1)

    } else {
        startIp = ip
        endIp = ip
    }
    return startIp, endIp, nil
}

在浏览器查看

然后在浏览器打开http://127.0.0.1:8888/debug/pprof/就能看到数据了

image.png

通过终端查看

也可以在终端使用go tool 工具查看
go tool pprof http://127.0.0.1:8888/debug/pprof/profile
使用 list 命令查看指定函数耗时

image.png

使用 top n 命令查看耗时最高的n个函数

image.png

通过 graphviz 工具导出 svg 图查看

(没有 graphviz 的话，在 centos 上可以通过 sudo yum install graphviz 命令下载
执行命令 go tool pprof -svg [go 项目编译的二进制] [prof pb文件, 如pprof.collector.samples.cpu.001.pb] > cpu.svg
然后在浏览器中打开 cpu.svg 图片即可