為golang程序使用pprof遠程查看httpserver運行堆棧,cpu耗時等信息

pprof是個神馬玩意兒？

pprof - manual page for pprof (part of gperftools)

是gperftools工具的一部分

gperftools又是啥？

These tools are for use by developers so that they can create more robust applications. Especially of use to those developing multi-threaded applications in C++ with templates. Includes TCMalloc, heap-checker, heap-profiler and cpu-profiler.

一個性能分析的工具，可以查看堆棧、cpu信息等等。

 

在golang中如何使用呢？下面就來看看。

 

1. 在一個httpserver中，只需要一行代碼

 

package main

import (
"flag"
"log"
"net/http"
_ "net/http/pprof"
"sync"
"time"
)


func main() {
flag.Parse()

//這里實現了遠程獲取pprof數據的接口
go func() { log.Println(http.ListenAndServe("localhost:6060", nil)) }()

var wg sync.WaitGroup
wg.Add(10)
for i := 0; i < 10; i++ {
go work(&wg)
}

wg.Wait()
// Wait to see the global run queue deplete.
time.Sleep(3 * time.Second)
}

func work(wg *sync.WaitGroup) {
time.Sleep(time.Second)

var counter int
for i := 0; i < 1e10; i++ {
time.Sleep(time.Millisecond * 100)
counter++
}
wg.Done()
}

2.編譯運行這個程序

go build trace_example.go

./trace_example

 

3. 通過瀏覽器訪問

http://localhost:6060/debug/pprof/

能夠查看到程序的overview

 

 

 

4.你也可以通過終端命令查看

Then use the pprof tool to look at the heap profile:

go tool pprof http://localhost:6060/debug/pprof/heap

Or to look at a 30-second CPU profile:

go tool pprof http://localhost:6060/debug/pprof/profile

Or to look at the goroutine blocking profile:

go tool pprof http://localhost:6060/debug/pprof/block

qpzhang@qpzhangdeMac-mini:~/gocode $go tool pprof http://localhost:6060/debug/pprof/profile
Read http://localhost:6060/debug/pprof/symbol
Gathering CPU profile from http://localhost:6060/debug/pprof/profile?seconds=30 for 30 seconds to
  /var/folders/2l/195zcc1n0sn2wjfjwf9hl9d80000gn/T/mmBnpdkv0D
Be patient...
Wrote profile to /var/folders/2l/195zcc1n0sn2wjfjwf9hl9d80000gn/T/mmBnpdkv0D
Welcome to pprof!  For help, type 'help'.
(pprof) top10
Total: 9 samples
       6  66.7%  66.7%        6  66.7% runtime.mach_semaphore_wait
       1  11.1%  77.8%        1  11.1% runtime.kevent
       1  11.1%  88.9%        1  11.1% runtime.mach_semaphore_signal
       1  11.1% 100.0%        1  11.1% runtime.mach_semaphore_timedwait
       0   0.0% 100.0%        7  77.8% System
       0   0.0% 100.0%        1  11.1% notetsleep
       0   0.0% 100.0%        1  11.1% ready
       0   0.0% 100.0%        2  22.2% runtime.gosched0
       0   0.0% 100.0%        1  11.1% runtime.mach_semrelease
       0   0.0% 100.0%        1  11.1% runtime.notetsleepg
(pprof) web
Total: 9 samples
Loading web page file:////var/folders/2l/195zcc1n0sn2wjfjwf9hl9d80000gn/T/SlFUZhzBDB.0.svg

web命令生成了很cool的svg圖片，在瀏覽器中打開。

除了遠程拉取，你還可以自己編寫代碼，把這些數據寫入文件（實現 net/http/pprof 中的幾個路由，開啟或關閉追蹤信息）。
具體可參考：http://blog.golang.org/profiling-go-programs
https://github.com/hyper-carrot/go_command_tutorial/blob/master/0.12.md

期間：web命令依賴一個svg生成包，在mac下面，你可以通過http://www.graphviz.org/Download_macos.php進行下載。

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2016.11.14 updated

基於uninx domain socket 的agent，可以不用走http

https://github.com/google/gops

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