The body of a successful response to a request would contain the requested resource (e.g. a new HTML page, or an image), which could then be displayed by the web browser. In the modern world of web development, learning about server-side development is highly recommended. This my first time in Node JS and read many articles on the architecture, but your article made the concept so clear. As I’m a Java Developer, I will try to explain “How Event Loop works” in Java terminology. If you face any issues in understanding this, please drop me a comment. Today we will look into Node JS Architecture and Single Threaded Event Loop model.
Requests for dynamic resources are instead forwarded (2) to server-side code (shown in the diagram as a Web Application). The diagram below shows a simple architecture for a dynamic website. As in the previous diagram, browsers send HTTP requests to the server, then the server processes the requests and returns appropriate HTTP responses. Before starting some Node JS programming examples, it’s important to have an idea about Node JS architecture. We will discuss about “How Node JS works under-the-hood, what type of processing model it is following, How Node JS handles concurrent request with Single-Threaded model” etc. in this post. Using a microservice offers flexibility and performance benefits that can’t be achieved with a monolithic application.
A connection pool is a cache of database connections that Sequelize uses to avoid creating a new connection for each request, which would take time and resources. The Node.js server.timeout property indicates the number of milliseconds of inactivity before a socket is presumed to have timed out. A socket is considered inactive when no data is being transferred in either direction within the specified timeout. By default, it is set to 0, meaning that there are no timeouts and connections can hang forever. When a client makes a request to the server, a connection between the two is established. Incoming request timeouts specify how long these client connections can last without any data being sent or received.
This includes selecting and styling UI components, creating layouts, navigation, form validation, etc. By contrast, server-side website programming mostly involves choosing which content is returned to the browser in response to requests. The server-side code handles tasks like validating submitted data and requests, using databases to store and retrieve data and sending the correct data to the client as required.
To create a connection to the server, you would use the net.createConnection() method. If you specify a port and host in the arguments, then it will create a TCP connection. However, if you specify a string path, it will create an IPC connection. Server.listen() method is used to initiate a server and wait for incoming connections. The type of server that is created depends on what the method is listening to.
Banks use server-side programming to store account information and allow only authorized users to view and make transactions. Other services like Facebook, Twitter, Instagram, and Wikipedia use server-side programming to highlight, share, and control access to interesting content. The diagram below shows a basic web server architecture for a static node js development site (a static site is one that returns the same hard-coded content from the server whenever a particular resource is requested). When a user wants to navigate to a page, the browser sends an HTTP “GET” request specifying its URL. Now that we’re done with the about.js route module, we’ll create the route that handles the weather info request.
We learned why Node.js is a great choice for building microservices, and we ran through an example using the OpenWeather API. You can make a simple GET request by clicking on a link or searching on a site (like a search engine homepage). We can see that two clients were connected to the server(their IP addresses were logged and you can notice that there are 2 different IP addresses one for each client). Then the server received a message from each client and send back a response and finally closes the connection for each client. Note that onClientConnection is a callback function which will be called each time a client is connected to the server. VPS servers offer base capabilities and environment to integrate Node.js apps with developer tools and APIs.
In the event queue, these requests will be processed one by one and pass to the event loop. The event loop will check the request is contains any blocking operations or it’s a simple request. Web servers wait for client request messages, process them when they arrive, and reply to the web browser with an HTTP Response message. The body of a successful response to a GET request would contain the requested resource.
In contrast to conventional methods, js uses a single limited thread to perform non-blocking I/O calls; therefore, accepting concurrent connections will consume fewer resources. The Node.js server offers effective handling of a large number of incoming requests through the usage of Event Queue and limited thread Pool. The main thread of a node does not wait for an externally initiated time-consuming process to finish. The Main Thread does not wait for the I/O single Function to finish execution while the Background Thread is doing it. The Main Thread is free to accept more Requests while the Async complex computation Task is completed in the background. After the Background Thread has finished running, it switches back to the Main Thread to continue running.
Encountering unexpected errors or behavior in your app can be unpleasant, and as a natural part of the development process, it’s something that can’t be entirely avoided when writing code. Having fewer flaws in the application leads to less time spent on debugging, resulting in cost savings for the project. Time becomes a critical factor as resources can now be allocated toward developing new features for the product. Having separately managed configurations also simplifies the identification and isolation of files containing sensitive information. When utilizing version control systems like Git, you can establish appropriate ignore rules to prevent the config folder or specific configuration files from being committed to the repository.
Node.js single-threading and asynchronous capabilities enable a non-blocking mechanism. When building a microservice with Node.js, developers will experience an uninterrupted flow and enjoy Node’s speed, scalability, and easy maintenance. You can serve your client side codes including other static files by locating them in public directory. If you decide to serve all files from nodejs server, you can develop without apache and avoid to write specific port number in your code. I think your application code should not be conscious about the port number you will use.
The API keys, database passwords, and other such information can be stored this way. It gets saved as a .env file that has all the environment variables. The dependency injection improves the scalability and understandability of code. All the communications are managed server-side and you can have different namespaces and rooms. So when A send a message, the server print it out to all other client (B in this context). The goal of this tutorial is to teach software developers the fundamentals of Node.js and its architectural ideas.
Have a look at yoeman.io, specifically it has project templates for express. Then, run the node server, open a browser and point it to that server and express will serve up “index.html” from the “public” folder. It is obviously related to the client side but the server (expressJS) is loading it when the server. I aspire for disconnecting all of the dependencies between the server code and the client code, in the sense that each side can stand alone by its own.
อัพเดทล่าสุด : 10 พฤศจิกายน 2023