go pprof详细理解及使用

￡神魔★判官ぃ 2023-06-10 05:20 62阅读 0赞

## 一、概述 ##

在Go语言中，我们可以通过标准库的代码包runtime和runtime/pprof中的程序来生成三种包含实时性数据的概要文件，分别是CPU概要文件、内存概要文件和程序阻塞概要文件。

**cpu概要文件**

在默认情况下，Go语言的运行时系统会以100 Hz的的频率对CPU使用情况进行取样。

**内存概要文件**

内存概要文件用于保存在用户程序执行期间的内存使用情况。这里所说的内存使用情况，其实就是程序运行过程中堆内存的分配情况。

**程序阻塞概要文件**

程序阻塞概要文件用于保存用户程序中的Goroutine阻塞事件的记录。

<table style="margin-left:6.75pt;width:517pt;"> 
 <tbody> 
 <tr> 
 <td style="border-color:#dddddd;"> 名称 </td> 
 <td style="border-color:#dddddd;"> 说明 </td> 
 <td style="border-color:#dddddd;width:198.75pt;"> 取样频率 </td> 
 </tr> 
 <tr> 
 <td style="border-color:#dddddd;"> goroutine </td> 
 <td> 活跃Goroutine的信息的记录。 </td> 
 <td style="width:198.75pt;"> 仅在获取时取样一次。 </td> 
 </tr> 
 <tr> 
 <td style="border-color:#dddddd;"> threadcreate </td> 
 <td> 系统线程创建情况的记录。 </td> 
 <td style="width:198.75pt;"> 仅在获取时取样一次。 </td> 
 </tr> 
 <tr> 
 <td style="border-color:#dddddd;"> heap </td> 
 <td> 堆内存分配情况的记录。 </td> 
 <td style="width:198.75pt;"> 默认每分配512K字节时取样一次。 </td> 
 </tr> 
 <tr> 
 <td style="border-color:#dddddd;"> block </td> 
 <td> Goroutine阻塞事件的记录。 </td> 
 <td style="width:198.75pt;"> 默认每发生一次阻塞事件时取样一次。 </td> 
 </tr> 
 </tbody> 
</table>

## 二、引入pprof ##

import  _ "net/http/pprof"
    
    go func() {
        http.ListenAndServe("0.0.0.0:6060", nil)
    }()

##   三、pprof使用 ##

###   1. 浏览器访问 ###

在浏览器输入[http://ip:6060/debug/pprof][http_ip_6060_debug_pprof]可以看到

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70][]

profiles下分别是block(阻塞情况)、goroutine数量、heap(堆)、mutex(锁)和threadcreate(创建的物理线程)

点击heap可以看到如下堆内存及GC相关的参数信息

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 1][]

看到这里是调用Go底层的runtime.MemStats结构体获取，该结构体相关字段解释如下

Alloc uint64 //golang语言框架堆空间分配的字节数
    TotalAlloc uint64 //从服务开始运行至今分配器为分配的堆空间总 和，只有增加，释放的时候不减少
    Sys uint64 //服务现在系统使用的内存
    Lookups uint64 //被runtime监视的指针数
    Mallocs uint64 //服务malloc heap objects的次数
    Frees uint64 //服务回收的heap objects的次数
    HeapAlloc uint64 //服务分配的堆内存字节数
    HeapSys uint64 //系统分配的作为运行栈的内存
    HeapIdle uint64 //申请但是未分配的堆内存或者回收了的堆内存（空闲）字节数
    HeapInuse uint64 //正在使用的堆内存字节数
    HeapReleased uint64 //返回给OS的堆内存，类似C/C++中的free。
    HeapObjects uint64 //堆内存块申请的量
    StackInuse uint64 //正在使用的栈字节数
    StackSys uint64 //系统分配的作为运行栈的内存
    MSpanInuse uint64 //用于测试用的结构体使用的字节数
    MSpanSys uint64 //系统为测试用的结构体分配的字节数
    MCacheInuse uint64 //mcache结构体申请的字节数(不会被视为垃圾回收)
    MCacheSys uint64 //操作系统申请的堆空间用于mcache的字节数
    BuckHashSys uint64 //用于剖析桶散列表的堆空间
    GCSys uint64 //垃圾回收标记元信息使用的内存
    OtherSys uint64 //golang系统架构占用的额外空间
    NextGC uint64 //垃圾回收器检视的内存大小
    LastGC uint64 // 垃圾回收器最后一次执行时间。
    PauseTotalNs uint64 // 垃圾回收或者其他信息收集导致服务暂停的次数。
    PauseNs [256]uint64 //一个循环队列，记录最近垃圾回收系统中断的时间
    PauseEnd [256]uint64 //一个循环队列，记录最近垃圾回收系统中断的时间开始点。
    NumForcedGC uint32 //服务调用runtime.GC()强制使用垃圾回收的次数。
    GCCPUFraction float64 //垃圾回收占用服务CPU工作的时间总和。如果有100个goroutine，垃圾回收的时间为1S,那么就占用了100S。
    BySize //内存分配器使用情况

### 2. go tool pprof命令行查看 ###

go tool pprof --help命令可以查看该命令行的详细使用说明。

> go tool pprof --help
 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 profile
 
 pprof [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 browser
 
 Options:
 -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
 -mean Average sample value over first value (count)
 -nodecount Max number of nodes to show
 -nodefraction Hide nodes below <f>*total
 -normalize Scales profile based on the base profile.
 -output Output filename for file-based outputs
 -positive_percentages Ignore negative samples when computing percentages
 -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
 -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
 -tagshow Only consider tags matching this regexp
 -trim Honor nodefraction/edgefraction/nodecount defaults
 -unit Measurement units to display
 
 Option groups (only set one per group):
 cumulative 
 -cum Sort entries based on cumulative weight
 -flat Sort entries based on own weight
 granularity 
 -addresses Aggregate at the function level.
 -addressnoinlines Aggregate at the function level, including functions' addresses in the output.
 -files Aggregate at the file level.
 -functions Aggregate at the function level.
 -lines Aggregate at the source code line level.
 -noinlines Aggregate at the function level.
 
 Source 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 profile
 Displayed on some reports or with pprof -comments
 -base source Source of profile to use as baseline
 profile.pb.gz Profile in compressed protobuf format
 legacy_profile Profile in legacy pprof format
 http://host/profile URL for profile handler to retrieve
 -symbolize= Controls source of symbol information
 none Do not attempt symbolization
 local Examine only local binaries
 fastlocal Only get function names from local binaries
 remote Do not examine local binaries
 force Force re-symbolization
 Binary Local path or build id of binary for symbolization
 
 
 Misc options:
 -http Provide web based interface at host:port.
 Host is optional and 'localhost' by default.
 Port is optional and a randomly available port by default.
 -tools Search path for object tools
 
 Legacy 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=delay
 
 Environment Variables:
 PPROF_TMPDIR Location for saved profiles (default $HOME/pprof)
 PPROF_TOOLS Search path for object-level tools
 PPROF_BINARY_PATH Search path for local binary files
 default: $HOME/pprof/binaries
 finds binaries by $name and $buildid/$name
 * On Windows, %USERPROFILE% is used instead of $HOME

从以上我们可以看到该命令可以指定输出的格式化类型，以及可选参数。我们只针对其中常用的进行探讨。

如果想输出图片相关格式需要先安装graphviz,graphviz安装地址如下：

linux源码安装地址：[https://graphviz.gitlab.io/\_pages/Download/Download\_source.html][https_graphviz.gitlab.io_pages_Download_Download_source.html]

windows下载地址：[https://graphviz.gitlab.io/\_pages/Download/Download\_windows.html][https_graphviz.gitlab.io_pages_Download_Download_windows.html]

可参考：[https://blog.csdn.net/skh2015java/article/details/102748065][https_blog.csdn.net_skh2015java_article_details_102748065]

**查看内存使用情况**

> go tool pprof  http://ip:6060/debug/pprof/heap

会进入如下gdb交互模式:

![20191025184842988.png][]

> help可以查看使用说明
    
    > top 可以查看前10个的内存分配情况
    
    > tree 以树状显示
    
    > png 以图片格式输出
    
    > svg 生成浏览器可以识别的svg文件

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 2][]

**cpu概要文件(cpu使用情况)**

> go tool pprof  http://ip:6060/debug/pprof/profile

默认需要等30s

常用操作同上

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 3][]

感谢：

[http://wiki.jikexueyuan.com/project/go-command-tutorial/0.12.html][http_wiki.jikexueyuan.com_project_go-command-tutorial_0.12.html]

[http://www.iargs.cn/?p=62][http_www.iargs.cn_p_62]

[http_ip_6060_debug_pprof]: http://ip:6060/debug/pprof
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70]: /images/20230531/baf661728866497bbdd1a961ef9339e1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 1]: /images/20230531/92e3d071ca6248cebc830d0777f3c7b0.png
[https_graphviz.gitlab.io_pages_Download_Download_source.html]: https://graphviz.gitlab.io/_pages/Download/Download_source.html
[https_graphviz.gitlab.io_pages_Download_Download_windows.html]: https://graphviz.gitlab.io/_pages/Download/Download_windows.html
[https_blog.csdn.net_skh2015java_article_details_102748065]: https://blog.csdn.net/skh2015java/article/details/102748065
[20191025184842988.png]: /images/20230531/9f57b35b2fca4ae3b5bb7cfac8d58804.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 2]: /images/20230531/ab3fac40bdda47b786d6ca7939c1d1ec.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NraDIwMTVqYXZh_size_16_color_FFFFFF_t_70 3]: /images/20230531/ef8d3a973c734006a592876285ee2a8a.png
[http_wiki.jikexueyuan.com_project_go-command-tutorial_0.12.html]: http://wiki.jikexueyuan.com/project/go-command-tutorial/0.12.html
[http_www.iargs.cn_p_62]: http://www.iargs.cn/?p=62