如何在 Mac 上分析 Node.js 配置文件？

Question

我使用的是 Node.js 8.3。我使用node --prof server.js 来分析我的应用程序。我得到了一些类似 xxxx-v8.log 的文件。

我尝试使用https://www.npmjs.com/package/node-tick-processor 和https://github.com/sidorares/node-tick 来分析文件。我有兴趣查看 CPU 配置文件。

但是输出是这样的，帮助不大：

[Bottom up (heavy) profile]:
  Note: percentage shows a share of a particular caller in the total
  amount of its parent calls.
  Callers occupying less than 2.0% are not shown.

   ticks parent  name
  65591   59.5%  /usr/lib/system/libsystem_kernel.dylib
  42621   65.0%    /usr/local/bin/node

  16632   15.1%  /usr/local/bin/node
   5544   33.3%    /usr/local/bin/node

   5888    5.3%  /usr/lib/system/libsystem_c.dylib
   5875   99.8%    /usr/local/bin/node

   2702    2.4%  /usr/lib/system/libsystem_pthread.dylib
   2284   84.5%    /usr/local/bin/node


 [Top down (heavy) profile]:
  Note: callees occupying less than 0.1% are not shown.

  inclusive      self           name
  ticks   total  ticks   total
  68106   61.7%  11088   10.1%  /usr/local/bin/node
  42617   38.6%  42617   38.6%    /usr/lib/system/libsystem_kernel.dylib
   5875    5.3%   5875    5.3%    /usr/lib/system/libsystem_c.dylib
   5548    5.0%   5538    5.0%    /usr/local/bin/node
   2284    2.1%   2284    2.1%    /usr/lib/system/libsystem_pthread.dylib
    337    0.3%    337    0.3%    /usr/lib/system/libsystem_platform.dylib
    303    0.3%    303    0.3%    /usr/lib/system/libsystem_malloc.dylib

  22970   20.8%  22970   20.8%  /usr/lib/system/libsystem_kernel.dylib

    418    0.4%    418    0.4%  /usr/lib/system/libsystem_pthread.dylib

还有其他工具可以分析输出文件吗？我想看到一些显示瓶颈功能的东西，或者至少为我找到行号。我试过v8-profiler，它的输出文件需要加载到 Chrome 开发工具上。但格式看起来不同。我不确定我是否还能分析-v8.log 文件。

Answer 1

您的工具使用绝对没有问题。这里的问题是named JS 函数对 CPU 消耗的贡献太小，无法在沉重的配置文件中看到。请注意您的个人资料输出中的警告（未显示少于 0.1% 的被调用者。）

考虑我的代码：

var x = 10;
function foo() {
  while (true) {
    x++;
  }
}
foo();

这是 prof 输出。如您所见，脚本、函数及其行 # 出现，作为主要的 CPU 消耗者。

 [Unknown]:
   ticks  total  nonlib   name
     13    0.3%

 [Shared libraries]:
   ticks  total  nonlib   name
     57    1.3%    0.0%  /usr/local/bin/node
      6    0.1%    0.0%  /usr/lib/system/libsystem_kernel.dylib
      2    0.0%    0.0%  /usr/lib/system/libsystem_platform.dylib
      1    0.0%    0.0%  /usr/lib/system/libsystem_pthread.dylib
      1    0.0%    0.0%  /usr/lib/system/libsystem_c.dylib

 [JavaScript]:
   ticks  total  nonlib   name
   4177   98.1%   99.7%  LazyCompile: *foo /Users/gireesh/a.js:2:13
      1    0.0%    0.0%  Stub: BinaryOpWithAllocationSiteStub

 [C++]:
   ticks  total  nonlib   name

 [GC]:
   ticks  total  nonlib   name
      2    0.0%

 [Bottom up (heavy) profile]:
  Note: percentage shows a share of a particular caller in the total
  amount of its parent calls.
  Callers occupying less than 2.0% are not shown.

   ticks parent  name
   4177   98.1%  LazyCompile: *foo /Users/gireesh/a.js:2:13
   4177  100.0%    LazyCompile: *foo /Users/gireesh/a.js:2:13
   4177  100.0%      Function: ~<anonymous> /Users/gireesh/a.js:1:11
   4177  100.0%        Function: ~Module._compile module.js:526:37
   4177  100.0%          Function: ~Module._extensions..js module.js:578:37
   4177  100.0%            Function: ~Module.load module.js:494:33

希望这会有所帮助。