Why is nodejs so fast?

If you are right about Node.js Shocked by the popularity of , So you're not alone . Don't worry , You're not the only one who feels this way .Node.js since 2009 Since its birth in, it has swept the field of online and application development , Become the most popular development environment .

Node.js There are many reasons why . For beginners , It has a large active community and a simple learning curve . This is probably PayPal、LinkedIn and Uber And other major brands use this framework and praise it for its excellent results .

In this paper , We will introduce Node.js And JavaScript The rest of the framework is different for each feature .

What makes Node.js So fast ？

When we talk about Node.js when , The first thing that comes to mind is the execution speed . therefore , In this section , We will try to figure out why Node.js Faster than the others . First , understand “ Execution speed ” The meaning of .

Execution speed can mean anything from computing Fibonacci numbers to searching databases .

Web Execution speed in the context of a service is all that is required to process requests and respond to clients . It is the time it takes to process the request , Start with the first connection , End when the client receives the response .

Let's take a look Node.js Several reasons why it is so fast ：

• Node.js Is single threaded and asynchronous . That means all I/O Activities do not interfere with other processes . You can also send emails at the same time 、 Read the document 、 Query the database and so on .
• Yes Web Every request from the server will not have a different Node.js process . however , One Node.js The process will always run , Listening to the connection . all JavaScript The code runs in the main thread of the process , And all the others I/O Activities run in different threads , There is little delay .
• Responsible for the execution of JavaScript Of Node.js (V8) Virtual machine usage in JIT compile . At run time , Virtual machines can get source code and compile it into machine code . This means that all commonly used “ heat ” Functions can be compiled into machine code , So as to speed up the execution .

These views give us a deep understanding of Node.js Why so fast . Let's see what makes Node.js Completed all this .

Learn about asynchrony

With examples , We will try to master the concept of asynchronous processing .

Suppose you are on the top of the mountain , There is 100 A ball . Your goal is to send all the balls to the foot of the mountain in the shortest time . You obviously can't press all the balls at once , So you have to press one at a time . At this point you have two choices ：

In the first way , You can push a ball , Then wait for it to reach the bottom , Then move on to the next . however , This method takes a long time to push all the balls to the bottom .

In the second way , You can push the ball one by one , Without waiting for them to reach the bottom . Using this method , You can push all... In the shortest possible time 100 A ball .

The first method is synchronous execution , The second method in this case is asynchronous execution . The previous example demonstrates that asynchronous execution is much faster than synchronous operation .

Now you have mastered the basics of asynchronous programming , Let's see how it helps Web Server performance .

Suppose each ball corresponds to a database query . therefore , If you have a lot of aggregations for one 、 Large projects such as search process data synchronously , Code execution will be blocked . however , If you are processing it asynchronously , You can run all the queries at once , And then collect the results .

On the back end ,Node.js And Angular、React、React Native and Vue.js Combination , Provide lightning like processing and rendering .

The event loop

An event loop is a mechanism responsible for scheduling events in a program that always runs asynchronously with the message originator .

When using Node.js when , It will be executed in you I/O The callback assigned to the operation is reserved during the operation , This allows you to continue with other events . Once all the necessary data has been collected , The callback will be called .

Web The server sends all requests to the event loop , The event loop registers an operation in the thread pool and assigns a callback to it .

Once the request is processed , The callback will be called . Other activities with high requirements , For example, search database , Callbacks can be used to perform .

V8 Role in optimizing code

V8 It consists of two types of compilers ：

• Complete compiler
• Crankshaft compiler

The entire compiler is known for its speed and ability to generate general-purpose code . It will also JavaScript Abstract syntax tree of function (AST) Convert to general native Code . At this level , It performs only one optimization ： inline caching .

V8 Start the parser thread at code execution time and compile the functions to determine which functions are hot , Which are not . Besides , It also captures type feedback , This helps V8 The record is passing through its data type .

Identifying “ heat ” Function and collect some types of feedback ,V8 Try optimizing the compiler （ Sometimes called “Crankshaft” compiler ） Perform enhanced AST.Crankshaft The compiler is slow , But it will try to generate efficient code . It consists of two compilers ：hydrogen and lithium.

Hydrogen The compiler works from AST File creation control flow diagram (CFG). The resulting graph shows a static single allocation (SSA) chart .

With the help of SSA A simple structure of forms and high-level intermediate representations , The compiler can perform many optimizations , For example, method inlining 、 Constant folding, etc .

Lithium The main goal of the compiler is to optimize the HIR Convert to LIR.LIR Very similar to machine code , But it has nothing to do with the platform .

after , old 、 The non optimized code will be replaced by the optimized code . This helps to execute code faster .

5 The best Node.js Use cases

Besides speed ,Node.js It also contains many functions that developers can use in a range of applications . Let's take a look at some classic Node.js Use cases .

Real time applications

When asked “Node.js What is the best use case for ？” Real time applications are a good answer . This is a Node.js A good application . Let's see why Node.js So popular in real-time applications ：

• Node.js Support for reusing and sharing for repository code Node.js package .
• It leads to fast data synchronization between the server and the client .
• It can easily handle multiple client requests .

All in all , If real-time data processing and scalability are two important considerations for your project , that Node.js Is the best technology .

More Than This , It should be used in real-time application development Node.js There are many reasons . therefore , If someone wants to know why you chose Node.js To develop real-time applications , That's why .

Event based servers

Multiple real-time users must be handled in real-time applications . This is it. Node.js Where it comes in handy , Because it can handle the response of event driven server , So as to realize non blocking function .

Data synchronization

Node.js Developers use non blocking I/O function . It also allows fast data transfer between clients and servers .

proxy server

Whenever an intermediate administrator is needed ,Node.js It's the ideal choice . To put Node.js As a proxy server , Developers must write 20 Line code . after , Your application will be ideal for streaming data from many sources .

Highly scalable applications

Node.js Has become the preferred platform for all applications and platforms with a steadily growing user base . Wal-Mart 、 PayPal 、 Uber 、Netflix、LinkedIn Companies are using Node.js, Because it allows seamless expansion .

Node.js Its cutting-edge technology includes cluster module and other functions . It provides services across multiple CPU Load balancing of the kernel , It is easier to provide the desired results through smaller modules , Without exhausting RAM.

More Than This ,Node.js There is also a non blocking event loop system , Allow the server to process requests in real time .

In terms of development ,Node.js Allow you to use microservices , This further allows you to break down the application into smaller components .

By effectively defining and assigning tasks between different teams , You can accelerate the development of each component of the application 、 Deployment and maintenance .

With Node.js, Modern applications can be expanded and reduced as needed . It can also help enterprises achieve higher performance with fewer resources .

Server side agents

In online applications , Third party agents can cause serious damage . Many common third-party servers , for example Nginx and HAProxy, Sometimes it is difficult to handle simultaneous requests .

Node.js Can be a savior , Because it can be easily used as a server-side proxy , Because it can handle a large number of simultaneous connections , While keeping non blocking .

BBC News yes NodeJS An example of an application .BBC News websites interact with many third-party servers , And gather information from a variety of sources .Node.js Assist agents with various services with different response times .

If the agent infrastructure is not up to standard , Or you need to develop a solution locally , You can use Node.js.

It means that you can Node.js Development servers are used for assets and stubs API Query to create client applications . In production , image HAProxy and nginx Such a dedicated proxy server can handle such transactions .

Conclusion

With its lightning fast execution speed ,Node.js It has proved to be the Savior of many developers and enterprises . Many big companies take advantage of Node.js This characteristic of . In this article, we explain in great detail what makes Node.js So fast and unique .