【go语言开发】性能分析工具pprof使用

本文主要介绍如何在项目中使用pprof工具。首先简要介绍pprof工具的作用；然后介绍pprof的应用场景，主要分为工具型应用和服务型应用。最后数据分析项目，先采集项目信息，再可视化查看

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前言

pprof是Go语言的一个性能分析库，它的名字源于**“Profile”（简称"prof"）**一词。该工具最早由Google开发并用于Go语言的性能分析，它可以帮助开发者找出程序中的性能瓶颈。pprof提供了CPU分析、内存分析、阻塞分析等多种性能分析功能。

1. CPU分析：

• pprof可以通过采样应用程序的运行状态来分析CPU的使用情况，找出哪些函数占用了大量的CPU时间。
• 提供CPU使用率最高的函数列表和调用关系，帮助定位程序的CPU性能瓶颈。

2. 内存分析：

• 支持对应用程序的内存分配和使用情况进行分析，帮助开发人员发现内存泄漏、高内存消耗的函数等问题。
• 提供内存使用最多的函数列表和调用关系，帮助优化内存管理和减少不必要的内存分配。

3. 阻塞分析：

• pprof可以分析应用程序中的阻塞情况，识别并发执行过程中可能存在的阻塞问题。
• 提供阻塞最严重的代码段和调用关系，帮助优化并发执行的性能和减少阻塞时间。

4. goroutine分析：

• 支持对应用程序中goroutine的跟踪和分析，帮助理解并发执行情况。
• 提供goroutine的数量、状态和调用关系等信息，帮助优化并发编程和避免goroutine泄漏。

5. 堆分析：

• pprof可以生成堆内存分配和释放的时间序列图，帮助开发人员了解程序在运行过程中的内存分配情况。
• 提供堆内存使用的趋势和波动情况，帮助优化内存管理和减少内存占用。

除了这些功能外，pprof还提供了对运行时调用图的可视化展示。pprof可以很容易地集成到任何Go程序中，只需在程序中导入net/http/pprof包，并启动一个HTTP服务器，就可以通过Web界面查看性能数据。

应用场景

pprof工具的应用场景主要分为两种：

• 服务型应用：web服务性能分析
• 工具型应用：输入命令行应用等

工具型应用

如果你想在不使用HTTP服务的情况下对应用程序进行性能分析，可以直接使用 runtime/pprof 包中提供的函数来生成性能分析数据。

package mainimport ("log""os""runtime""runtime/pprof""time"
)func main() {Analysis()
}func Analysis() {// 创建 CPU 分析文件cpuProfile, err := os.Create("./profile/cpu.prof")if err != nil {log.Fatal(err)}defer cpuProfile.Close()// 开始 CPU 分析if err := pprof.StartCPUProfile(cpuProfile); err != nil {log.Fatal(err)}defer pprof.StopCPUProfile()// 模拟一些 CPU 密集型工作for i := 0; i < 1000000; i++ {_ = i * i}// 创建内存分析文件memProfile, err := os.Create("./profile/mem.prof")if err != nil {log.Fatal(err)}defer memProfile.Close()// 强制进行垃圾回收，以便获取准确的内存分析数据runtime.GC()// 开始内存分析if err := pprof.WriteHeapProfile(memProfile); err != nil {log.Fatal(err)}// 模拟一些内存使用data := make([]byte, 1024*1024)_ = datatime.Sleep(time.Second) // 等待一段时间以便生成分析数据log.Println("完成性能分析")
}

服务型应用

我们这里使用gin框架，结合https://github.com/gin-contrib/pprof

package mainimport (webpprof "github.com/gin-contrib/pprof""github.com/gin-gonic/gin""log""net/http""os""runtime""runtime/pprof""time"
)const Port = ":10000"func main() {WebAnalysis()
}func WebAnalysis() {g := gin.Default()g.GET("/test", func(c *gin.Context) {c.JSON(http.StatusOK, "测试成功")})webpprof.Register(g) // 注入HandlerFuncsg.Run(Port)}

启动后日志打印如下：

查看github.com/gin-contrib/pprof代码，发现gin.Engine将net/http/pprof的函数封装成标准的HandlerFuncs，也就是将func(w http.ResponseWriter, r *http.Request)格式函数转换为gin.HandlerFunc

package pprofimport ("net/http/pprof""github.com/gin-gonic/gin"
)const (// DefaultPrefix url prefix of pprofDefaultPrefix = "/debug/pprof"
)func getPrefix(prefixOptions ...string) string {prefix := DefaultPrefixif len(prefixOptions) > 0 {prefix = prefixOptions[0]}return prefix
}// Register the standard HandlerFuncs from the net/http/pprof package with
// the provided gin.Engine. prefixOptions is a optional. If not prefixOptions,
// the default path prefix is used, otherwise first prefixOptions will be path prefix.
func Register(r *gin.Engine, prefixOptions ...string) {RouteRegister(&(r.RouterGroup), prefixOptions...)
}// RouteRegister the standard HandlerFuncs from the net/http/pprof package with
// the provided gin.GrouterGroup. prefixOptions is a optional. If not prefixOptions,
// the default path prefix is used, otherwise first prefixOptions will be path prefix.
func RouteRegister(rg *gin.RouterGroup, prefixOptions ...string) {prefix := getPrefix(prefixOptions...)prefixRouter := rg.Group(prefix){prefixRouter.GET("/", gin.WrapF(pprof.Index))prefixRouter.GET("/cmdline", gin.WrapF(pprof.Cmdline))prefixRouter.GET("/profile", gin.WrapF(pprof.Profile))prefixRouter.POST("/symbol", gin.WrapF(pprof.Symbol))prefixRouter.GET("/symbol", gin.WrapF(pprof.Symbol))prefixRouter.GET("/trace", gin.WrapF(pprof.Trace))prefixRouter.GET("/allocs", gin.WrapH(pprof.Handler("allocs")))prefixRouter.GET("/block", gin.WrapH(pprof.Handler("block")))prefixRouter.GET("/goroutine", gin.WrapH(pprof.Handler("goroutine")))prefixRouter.GET("/heap", gin.WrapH(pprof.Handler("heap")))prefixRouter.GET("/mutex", gin.WrapH(pprof.Handler("mutex")))prefixRouter.GET("/threadcreate", gin.WrapH(pprof.Handler("threadcreate")))}
}

实际上net/http/pprof库中已初始化的函数有Index等，并在此基础上再wrap了heap、mutex等

// Package pprof serves via its HTTP server runtime profiling data
// in the format expected by the pprof visualization tool.
//
// The package is typically only imported for the side effect of
// registering its HTTP handlers.
// The handled paths all begin with /debug/pprof/.
//
// To use pprof, link this package into your program:
//
//	import _ "net/http/pprof"
//
// If your application is not already running an http server, you
// need to start one. Add "net/http" and "log" to your imports and
// the following code to your main function:
//
//	go func() {
//		log.Println(http.ListenAndServe("localhost:6060", nil))
//	}()
//
// By default, all the profiles listed in [runtime/pprof.Profile] are
// available (via [Handler]), in addition to the [Cmdline], [Profile], [Symbol],
// and [Trace] profiles defined in this package.
// If you are not using DefaultServeMux, you will have to register handlers
// with the mux you are using.
//
// # Usage examples
//
// 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?seconds=30
//
// Or to look at the goroutine blocking profile, after calling
// runtime.SetBlockProfileRate in your program:
//
//	go tool pprof http://localhost:6060/debug/pprof/block
//
// Or to look at the holders of contended mutexes, after calling
// runtime.SetMutexProfileFraction in your program:
//
//	go tool pprof http://localhost:6060/debug/pprof/mutex
//
// The package also exports a handler that serves execution trace data
// for the "go tool trace" command. To collect a 5-second execution trace:
//
//	curl -o trace.out http://localhost:6060/debug/pprof/trace?seconds=5
//	go tool trace trace.out
//
// To view all available profiles, open http://localhost:6060/debug/pprof/
// in your browser.
//
// For a study of the facility in action, visit
//
//	https://blog.golang.org/2011/06/profiling-go-programs.html
package pprofimport ("bufio""bytes""context""fmt""html""internal/profile""io""log""net/http""net/url""os""runtime""runtime/pprof""runtime/trace""sort""strconv""strings""time"
)
func init() {http.HandleFunc("/debug/pprof/", Index)http.HandleFunc("/debug/pprof/cmdline", Cmdline)http.HandleFunc("/debug/pprof/profile", Profile)http.HandleFunc("/debug/pprof/symbol", Symbol)http.HandleFunc("/debug/pprof/trace", Trace)
}

浏览器输入http://localhost:10000/debug/pprof/
pprof能分析9项信息

数据分析

命令行查看

go tool pprof
usage:Produce output in the specified format.pprof <format> [options] [binary] <source> ...Omit the format to get an interactive shell whose commands can be used
to generate various views of a profilepprof [options] [binary] <source> ...Omit the format and provide the "-http" flag to get an interactive web
interface at the specified host:port that can be used to navigate through
various views of a profile.pprof -http [host]:[port] [options] [binary] <source> ...Details:Output formats (select at most one):-callgrind       Outputs a graph in callgrind format-comments        Output all profile comments-disasm          Output assembly listings annotated with samples-dot             Outputs a graph in DOT format-eog             Visualize graph through eog-evince          Visualize graph through evince-gif             Outputs a graph image in GIF format-gv              Visualize graph through gv-kcachegrind     Visualize report in KCachegrind-list            Output annotated source for functions matching regexp-pdf             Outputs a graph in PDF format-peek            Output callers/callees of functions matching regexp-png             Outputs a graph image in PNG format-proto           Outputs the profile in compressed protobuf format-ps              Outputs a graph in PS format-raw             Outputs a text representation of the raw profile-svg             Outputs a graph in SVG format-tags            Outputs all tags in the profile-text            Outputs top entries in text form-top             Outputs top entries in text form-topproto        Outputs top entries in compressed protobuf format-traces          Outputs all profile samples in text form-tree            Outputs a text rendering of call graph-web             Visualize graph through web browser-weblist         Display annotated source in a web browserOptions:-call_tree       Create a context-sensitive call tree-compact_labels  Show minimal headers-divide_by       Ratio to divide all samples before visualization-drop_negative   Ignore negative differences-edgefraction    Hide edges below <f>*total-focus           Restricts to samples going through a node matching regexp-hide            Skips nodes matching regexp-ignore          Skips paths going through any nodes matching regexp-intel_syntax    Show assembly in Intel syntax-mean            Average sample value over first value (count)-nodecount       Max number of nodes to show-nodefraction    Hide nodes below <f>*total-noinlines       Ignore inlines.-normalize       Scales profile based on the base profile.-output          Output filename for file-based outputs-prune_from      Drops any functions below the matched frame.-relative_percentages Show percentages relative to focused subgraph-sample_index    Sample value to report (0-based index or name)-show            Only show nodes matching regexp-show_from       Drops functions above the highest matched frame.-source_path     Search path for source files-tagfocus        Restricts to samples with tags in range or matched by regexp-taghide         Skip tags matching this regexp-tagignore       Discard samples with tags in range or matched by regexp-tagleaf         Adds pseudo stack frames for labels key/value pairs at the callstack leaf.-tagroot         Adds pseudo stack frames for labels key/value pairs at the callstack root.-tagshow         Only consider tags matching this regexp-trim            Honor nodefraction/edgefraction/nodecount defaults-trim_path       Path to trim from source paths before search-unit            Measurement units to displayOption groups (only set one per group):granularity-functions       Aggregate at the function level.-filefunctions   Aggregate at the function level.-files           Aggregate at the file level.-lines           Aggregate at the source code line level.-addresses       Aggregate at the address level.sort-cum             Sort entries based on cumulative weight-flat            Sort entries based on own weightSource options:-seconds              Duration for time-based profile collection-timeout              Timeout in seconds for profile collection-buildid              Override build id for main binary-add_comment          Free-form annotation to add to the profileDisplayed on some reports or with pprof -comments-diff_base source     Source of base profile for comparison-base source          Source of base profile for profile subtractionprofile.pb.gz         Profile in compressed protobuf formatlegacy_profile        Profile in legacy pprof formathttp://host/profile   URL for profile handler to retrieve-symbolize=           Controls source of symbol informationnone                  Do not attempt symbolizationlocal                 Examine only local binariesfastlocal             Only get function names from local binariesremote                Do not examine local binariesforce                 Force re-symbolizationBinary                  Local path or build id of binary for symbolization-tls_cert             TLS client certificate file for fetching profile and symbols-tls_key              TLS private key file for fetching profile and symbols-tls_ca               TLS CA certs file for fetching profile and symbolsMisc options:-http              Provide web interface at host:port.Host is optional and 'localhost' by default.Port is optional and a randomly available port by default.-no_browser        Skip opening a browser for the interactive web UI.-tools             Search path for object toolsLegacy convenience options:-inuse_space           Same as -sample_index=inuse_space-inuse_objects         Same as -sample_index=inuse_objects-alloc_space           Same as -sample_index=alloc_space-alloc_objects         Same as -sample_index=alloc_objects-total_delay           Same as -sample_index=delay-contentions           Same as -sample_index=contentions-mean_delay            Same as -mean -sample_index=delayEnvironment Variables:PPROF_TMPDIR       Location for saved profiles (default $HOME/pprof)PPROF_TOOLS        Search path for object-level toolsPPROF_BINARY_PATH  Search path for local binary filesdefault: $HOME/pprof/binariessearches $buildid/$name, $buildid/*, $path/$buildid,${buildid:0:2}/${buildid:2}.debug, $name, $path* On Windows, %USERPROFILE% is used instead of $HOME
no profile source specified

采集数据

可以将每项数据统一采集下来，再具体分析

go tool pprof http://localhost:10000/debug/pprof/allocs
go tool pprof http://localhost:10000/debug/pprof/block
go tool pprof http://localhost:10000/debug/pprof/cmdline
go tool pprof http://localhost:10000/debug/pprof/heap
go tool pprof http://localhost:10000/debug/pprof/mutex
go tool pprof http://localhost:10000/debug/pprof/profile
go tool pprof http://localhost:10000/debug/pprof/threadcreate
go tool pprof http://localhost:10000/debug/pprof/trace

终端中运行以下命令，性能分析allocs数据：

在进入 pprof 命令行界面后，你可以输入不同的命令来查看不同类型的分析数据，比如 top 查看 CPU 使用最多的函数，list 查看某个函数的详细信息，web 可以在浏览器中打开交互式图形界面等。

查看数据

查看数据，可以选择web形式，可视化效果直观，打开收集好的pb.gz文件
UI显示依赖graphviz库 ，mac安装使用命令为：brew install graphviz

go tool pprof -http:127.0.0.1:port pb.gz路径 //参考截图使用

浏览器输入http://127.0.0.1:8082/ui/，UI上查看各项信息

top

查看CPU/内存占有率最高的接口

Graph

Flame Graph

Source