在golang中用来做监控分析的库包，一般用都是pprof库包… pprof可以在两个地方引入：
    Golang 使用pprof监控性能及GC调优先 - 图1
    其实net/http/pprof中只是使用runtime/pprof包来进行封装了一下，并在http端口上暴露出来。 runtime/pprof可以用来产生dump文件，再使用go tool pprof来分析这运行日志.

    使用net/http/pprof可以做到直接看到当前web服务的状态，包括CPU占用情况和内存使用情况等。

    这次重点说些pprof web显示的模式，我自己主要是关注heap,profile两个数据源。

    关于golang运行环境heap的信息、内存mem等：http://localhost:7777/debug/pprof/heap
    关于profile、CPU计算百分比等：http://localhost:7777/debug/pprof/profile

    上面简单介绍了pprof的监控接口，但怎么查看这些数据？ 有这么几个查看方式.
    交互模式, 可以通过用help查看pprof各种命令。 每次运行后拿到的数据是固定的，不会动态更新该数据。
    Golang 使用pprof监控性能及GC调优先 - 图2

    如果你不想使用交互模式，当然这每次都是新数据：
    Golang 使用pprof监控性能及GC调优先 - 图3

    网页查看模式: http://localhost:7777/debug/pprof/
    Golang 使用pprof监控性能及GC调优先 - 图4
    下面是我随便写的一段伪业务代码. 大家可以长时间运行这段代码，会发现内存在缓慢的增长中.

    1. #xiaorui.cc
    2. package main
    4. import (
    5.     "flag"
    6.     "fmt"
    7.     "io/ioutil"
    8.     "log"
    9.     "net/http"
    10.     _ "net/http/pprof"
    11.     "sync"
    12.     "time"
    13. )
    15. func counter() {
    16.     list := []int{1}
    17.     c := 1
    18.     for i := 0; i < 10000000; i++ {
    19.         httpGet()
    20.         c = i + 1 + 2 + 3 + 4 - 5
    21.         list = append(list, c)
    22.     }
    23.     fmt.Println(c)
    24.     fmt.Println(list[0])
    25. }
    27. func work(wg *sync.WaitGroup) {
    28.     for {
    29.         counter()
    30.         time.Sleep(1 * time.Second)
    31.     }
    32.     wg.Done()
    33. }
    35. func httpGet() int {
    36.     queue := []string{"start..."}
    37.     resp, err := http.Get("http://www.163.com")
    38.     if err != nil {
    39.         // handle error
    40.     }
    42.     //defer resp.Body.Close()
    43.     body, err := ioutil.ReadAll(resp.Body)
    44.     if err != nil {
    45.         // handle error
    46.     }
    47.     queue = append(queue, string(body))
    48.     return len(queue)
    49. }
    51. func main() {
    52.     flag.Parse()
    54.     //这里实现了远程获取pprof数据的接口
    55.     go func() {
    56.         log.Println(http.ListenAndServe("localhost:7777", nil))
    57.     }()
    59.     var wg sync.WaitGroup
    60.     wg.Add(10)
    61.     for i := 0; i < 100; i++ {
    62.         go work(&wg)
    63.     }
    65.     wg.Wait()
    66.     time.Sleep(3 * time.Second)
    67. }

    下面是pprof统计的heaq信息
    Golang 使用pprof监控性能及GC调优先 - 图5
    另外需要说的一点，pprof可以生成一个svg的矢量图，可以通过这svg图确认代码的流程及调用情况. svg是使用graphviz生成的，mac下直接brew install graphviz就能安装，centos下，yum -y install graphviz .

    下面是pprof help的使用文档.

    1. #xiaorui.cc
    2. $ go tool  pprof  http://localhost:6060/debug/pprof/heap
    3. Fetching profile from http://localhost:6060/debug/pprof/heap
    4. Saved profile in /Users/ruifengyun/pprof/pprof.localhost:6060.inuse_objects.inuse_space.032.pb.gz
    5. Entering interactive mode (type "help" for commands)
    6. (pprof) help
    8.  Commands:
    9.    cmd [n] [--cum] [focus_regex]* [-ignore_regex]*
    10.        Produce a text report with the top n entries.
    11.        Include samples matching focus_regex, and exclude ignore_regex.
    12.        Add --cum to sort using cumulative data.
    13.        Available commands:
    14.          callgrind    Outputs a graph in callgrind format
    15.          disasm       Output annotated assembly for functions matching regexp or address
    16.          dot          Outputs a graph in DOT format
    17.          eog          Visualize graph through eog
    18.          evince       Visualize graph through evince
    19.          gif          Outputs a graph image in GIF format
    20.          gv           Visualize graph through gv
    21.          list         Output annotated source for functions matching regexp
    22.          pdf          Outputs a graph in PDF format
    23.          peek         Output callers/callees of functions matching regexp
    24.          png          Outputs a graph image in PNG format
    25.          proto        Outputs the profile in compressed protobuf format
    26.          ps           Outputs a graph in PS format
    27.          raw          Outputs a text representation of the raw profile
    28.          svg          Outputs a graph in SVG format
    29.          tags         Outputs all tags in the profile
    30.          text         Outputs top entries in text form
    31.          top          Outputs top entries in text form
    32.          tree         Outputs a text rendering of call graph
    33.          web          Visualize graph through web browser
    34.          weblist      Output annotated source in HTML for functions matching regexp or address
    35.    peek func_regex
    36.        Display callers and callees of functions matching func_regex.
    38.    dot [n] [focus_regex]* [-ignore_regex]* [>file]
    39.        Produce an annotated callgraph with the top n entries.
    40.        Include samples matching focus_regex, and exclude ignore_regex.
    41.        For other outputs, replace dot with:
    42.        - Graphic formats: dot, svg, pdf, ps, gif, png (use > to name output file)
    43.        - Graph viewer:    gv, web, evince, eog
    45.    callgrind [n] [focus_regex]* [-ignore_regex]* [>file]
    46.        Produce a file in callgrind-compatible format.
    47.        Include samples matching focus_regex, and exclude ignore_regex.
    49.    weblist func_regex [-ignore_regex]*
    50.        Show annotated source with interspersed assembly in a web browser.
    52.    list func_regex [-ignore_regex]*
    53.        Print source for routines matching func_regex, and exclude ignore_regex.
    55.    disasm func_regex [-ignore_regex]*
    56.        Disassemble routines matching func_regex, and exclude ignore_regex.
    58.    tags tag_regex [-ignore_regex]*
    59.        List tags with key:value matching tag_regex and exclude ignore_regex.
    61.    quit/exit/^D
    62.          Exit pprof.
    64.    option=value
    65.        The following options can be set individually:
    66.            cum/flat:           Sort entries based on cumulative or flat data
    67.            call_tree:          Build context-sensitive call trees
    68.            nodecount:          Max number of entries to display
    69.            nodefraction:       Min frequency ratio of nodes to display
    70.            edgefraction:       Min frequency ratio of edges to display
    71.            focus/ignore:       Regexp to include/exclude samples by name/file
    72.            tagfocus/tagignore: Regexp or value range to filter samples by tag
    73.                                eg "1mb", "1mb:2mb", ":64kb"
    75.            functions:          Level of aggregation for sample data
    76.            files:
    77.            lines:
    78.            addresses:
    80.            unit:               Measurement unit to use on reports
    82.            Sample value selection by index:
    83.             sample_index:      Index of sample value to display
    84.             mean:              Average sample value over first value
    86.            Sample value selection by name:
    87.             alloc_space        for heap profiles
    88.             alloc_objects
    89.             inuse_space
    90.             inuse_objects
    92.             total_delay        for contention profiles
    93.             mean_delay
    94.             contentions
    96.    :   Clear focus/ignore/hide/tagfocus/tagignore
    97. (pprof)

    根据pprof的统计信息我们可以找到CPU过度计算及内存泄露的大概的点。 现在越来越觉得Golang gc有些让人摸不清头脑. 看来有必要深入学习Golang gc垃圾回收原理.

    Golang 使用pprof监控性能及GC调优先 - 图6