CODEWITHSUNDEEP
javascriptperformancenode.js
user1968030
user1968030

Reputation:

Node js performance in request process

Consider this code:

var http = require("http");
http.createServer(function(request, response) {
    for (var i = 0; i < 1000000; i++) {
        console.log("Request received");
    }
    response.writeHead(200, {
        "Content-Type": "text/plain"
    });
    response.write("Hello World");
    response.end();
}).listen(8888, "127.0.0.1");

If we run this code,we should wait for many minute too get response.But if run a for without console.log("Request received");in a for we get response with high speed? Why?

Upvotes: 1

Views: 269

Answers (4)

fardjad
fardjad

Reputation: 20394

First of all starting with v0.6, console.log() is synchronous (ie. it blocks the main event loop.)

You're writing around 17MBs to stdout on each request. It might take a few minutes for server to respond.

Upvotes: 1

basis
basis

Reputation: 158

Simply, one loop in a empty "for" takes nearly null time. But a output with console.log() need a bunch more time and its also synchronous.

Upvotes: 1

Thomas Skowron
Thomas Skowron

Reputation: 442

console.log is pretty slow like any other print/echo/sysout that does something on your STDOUT console.

EDIT: In addition to that, the interpreter will simply skip the loop if there is no operation in it. If you actually do something in it, it will of course take time.

Upvotes: 0

Mohammad
Mohammad

Reputation: 1304

I think because write console.log("Request received"); in console get time process.

Upvotes: 0

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