Node.js分析的最佳实践是什么？

Question

I don't want to use services like nodetime. I have small middleware nodejs application. And now I my application use cpu in strange way http://s27.postimg.org/fgzmmh85f/cpu.png So I need simple tools to profile my code. I tried to use node --prof app.js but Chrome Dev Tool doen't open generated log-file.

Please advise tool to find out bottlenecks. Also I can't understand how v8 garbidge collector works.

Answer 1

I'm not node expert, but I've been trying to profile some JS code for some time now. This is what I can tell you:

There are two ways to profile, but both provide the same data. The first one is running your code with node -- , which will generate an isolate*.log file. You give this file to node --prof-process and this will give you smoe output that, if you're kinda lucky, you can understand and act upon.

The second one is more or less like this:

var profiler = require('v8-profiler');
profiler.startProfiling('carto');

[your code here]

var profile = profiler.stopProfiling('carto');
profile.export(function(error, result) {
    fs.writeFileSync('carto.cpuprofile', result);
    profile.delete();
})

This will generate a .cpuprofile that you can load in chromium 's JS Profiler. This can be found in the Developer Tools, and you will have probably to enable the Javascript Profiler in the More Tools menu. This will give you three different ways to see in which functions you're spending time.