node.js中的节点到底是什么?-Whatexactlyisanodeinnode.js?

7  

Node.js has much more in common with Twisted than Erlang/OTP. Node.js is just a single threaded SEDA event loop. Node.js has nothing compared to Erlang VM when it comes to distribution, hot code reloading, and scalability via processes, it isn't anything close to "Erlang with Javascript sugar"

节点。js与Twisted比Erlang/OTP有更多的共同之处。节点。js只是一个单线程SEDA事件循环。节点。在分发、热代码重载和进程可扩展性等方面，js与Erlang虚拟机相比简直是小巫见大巫

7  

Maybe because of your Erlang knowledge you thought that somehow Node.js had something to do with "nodes" (as erlang nodes), but it's just the name.

也许是因为你的Erlang知识，你认为这个节点。js与“节点”(如erlang节点)有关，但它只是名称。

The main idea with Node.js is that you defer all expensive I/O operations and assign callbacks to the result of those operations. The reason is that I/O blocks the (only) process that is running at the moment. Node.js will handle this for you, given that you are coding in the proper way.

节点的主要思想。js是延迟所有昂贵的I/O操作并为这些操作的结果分配回调。原因是I/O阻塞了当前正在运行的(惟一的)进程。节点。js将为您处理这个问题，因为您正在以正确的方式进行编码。

An easy example of this is a database call:

一个简单的例子是数据库调用:

result = SQL.query("EXPENSIVE SELECT HERE")
doSomething(result);
moreStuff(); // This line must wait until the previous ones are completed.

In node you would code this in a very different way:

在node，你可以用一种非常不同的方式来编码:

SQL.query("EXPENSIVE SELECT HERE", function(result) {
  doSomething(result);
});
moreStuff(); // This line executes inmediately

If you have wrong code in your Node.js script, like:

如果您的节点中有错误的代码。js脚本,如:

while(true) { }

Then you are blocking the process and it won't be able to handle more requests than the current one, so in Node.js is mandatory to follow the above guidelines.

然后阻塞进程，它将无法处理比当前请求更多的请求，因此在Node中。js必须遵守以上准则。

4  

As I understand it, a Node.JS node is an instance of the V8 engine with the Node.JS runtime and event-loop running in it. While the Node.JS runtime gives you the ability to very quickly and simply begin processing HTTP requests, it's not mandatory; it is very good at handling most any kind of asynchronous I/O, really.

根据我的理解，是一个节点。JS节点是带有该节点的V8引擎的实例。JS运行时和事件循环在其中运行。而节点。JS运行时使您能够非常快速地开始处理HTTP请求，这不是强制性的;它非常擅长处理任何类型的异步I/O。

I don't know that much about Erlang, but my superficial understanding is that its great strength is high-concurrency computing. Node.JS doesn't specialize in that, per se. Its heart is "evented I/O", dealing neatly and cleanly with asynchronous I/O.

我不太了解Erlang，但我的表面理解是它的强大之处在于高并发计算。节点。JS本身并不擅长这个。它的核心是“唤醒I/O”，处理异步I/O时干净利落。

1  

there is no "node" in node.js

node.js中没有“node”

as mentioned, when you run

如前所述，当您运行时

node my_script.js 

you are running one instance of V8 java script interpreter (which is using one core for its lifetime).

您正在运行一个V8 java脚本解释器实例(在其生命周期中使用一个核心)。