I am trying to understand in which cases nodejs will be faster than its pros. I completely understood the terms Asynchronous I/O and non-blocking I/O but cant think of a use case where it is be useful. can somebody give me an example ?
我试图了解nodejs在哪些情况下会比其专业人员更快。我完全理解术语异步I / O和非阻塞I / O，但不能想到它有用的用例。有人可以举个例子吗？
2 个解决方案
#1
3
Node is a prime example why async I/O is useful.
节点是异步I / O有用的一个主要示例。
Node is (as far as the user is concerned) single threaded, so waiting for synchronous I/O would stop the only thread that is executing code. Since there are no guarantees how long I/O will take, that could/would make Node code run extremely slowly.
节点是（就用户而言）单线程，因此等待同步I / O将停止执行代码的唯一线程。由于无法保证I / O需要多长时间，因此可能会使节点代码运行得非常慢。
That's why Node pretty much uses only async I/O, it allows the single thread to quickly offload I/O work to the operating system while continuing code execution without interruption until the operating system notifies Node that the I/O operation is done.
这就是Node几乎只使用异步I / O的原因，它允许单个线程快速将I / O工作卸载到操作系统，同时继续执行代码而不会中断，直到操作系统通知Node I / O操作完成。
#2
0
NodeJS is basically a server side coding which is based on single threaded concept, so we have to manage all the I/O and CPU works on this thread itself.
NodeJS基本上是基于单线程概念的服务器端编码，因此我们必须管理此线程本身的所有I / O和CPU工作。
We know, I/O operations are basic blocking operation for the running thread (example: I/O operation may include getting an input from a user, or reading a large file from the data center; this operations may hang up the thread for sometime, which may results in hanging up many client request).
我们知道，I / O操作是正在运行的线程的基本阻塞操作（例如：I / O操作可能包括从用户获取输入，或从数据中心读取大文件;此操作可能会挂起线程一段时间，这可能导致挂起许多客户请求）。
To avoid this above cases, NodeJS came up with the concept of single thread asynchronous non-blocking I/O (also overcoming the overhead of creating multiple threads in case of multi-threading).
为了避免上述情况，NodeJS提出了单线程异步非阻塞I / O的概念（也克服了在多线程情况下创建多个线程的开销）。
#1
3
Node is a prime example why async I/O is useful.
节点是异步I / O有用的一个主要示例。
Node is (as far as the user is concerned) single threaded, so waiting for synchronous I/O would stop the only thread that is executing code. Since there are no guarantees how long I/O will take, that could/would make Node code run extremely slowly.
节点是（就用户而言）单线程，因此等待同步I / O将停止执行代码的唯一线程。由于无法保证I / O需要多长时间，因此可能会使节点代码运行得非常慢。
That's why Node pretty much uses only async I/O, it allows the single thread to quickly offload I/O work to the operating system while continuing code execution without interruption until the operating system notifies Node that the I/O operation is done.
这就是Node几乎只使用异步I / O的原因，它允许单个线程快速将I / O工作卸载到操作系统，同时继续执行代码而不会中断，直到操作系统通知Node I / O操作完成。
#2
0
NodeJS is basically a server side coding which is based on single threaded concept, so we have to manage all the I/O and CPU works on this thread itself.
NodeJS基本上是基于单线程概念的服务器端编码，因此我们必须管理此线程本身的所有I / O和CPU工作。
We know, I/O operations are basic blocking operation for the running thread (example: I/O operation may include getting an input from a user, or reading a large file from the data center; this operations may hang up the thread for sometime, which may results in hanging up many client request).
我们知道，I / O操作是正在运行的线程的基本阻塞操作（例如：I / O操作可能包括从用户获取输入，或从数据中心读取大文件;此操作可能会挂起线程一段时间，这可能导致挂起许多客户请求）。
To avoid this above cases, NodeJS came up with the concept of single thread asynchronous non-blocking I/O (also overcoming the overhead of creating multiple threads in case of multi-threading).
为了避免上述情况，NodeJS提出了单线程异步非阻塞I / O的概念（也克服了在多线程情况下创建多个线程的开销）。