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When Node.js performs an I / O operation, such as reading from a network, accessing a database or file system, operations occur when the Node.js response returns, instead of blocking threads and destroying the waiting CPU cycles. Will start again.
This allows Node.js to handle thousands of concurrent connections with a single server without introducing the burden of managing thread consistency, which can be a significant source of bugs.
The new ECMA Script standards in Node.js can be used without problems, as you do not need to wait for all your users to update their browsers – you are in charge of deciding that the ECMAScript version Node.jpg Which to use by changing the version. And you can also enable specific experimental features by running Node.js with flags.
With its simple structure npm helped the ecosystem of Node.js spread, and now the npm registry hosts over 1,000,000 open source packages that you can use independently.
Node.js has a great standard library, including first-class support for networking.
The createServer () method of creating a new HTTP server http and returns it.
The server is set to listen to the specified port and host name. When the server is ready, a callback function is called, in which case inform us that the server is running.
Whenever a new request is received, the request event is called, providing two objects: a request (a http.IncomingMessage object) and a response (a http.ServerResponse object).
Those 2 objects are required to handle HTTP calls.
The first request provides details. In this simple example, it is not used, but you can access request headers and request data.
The other is used to return data to the caller.
Node.js shines in real-time web applications, employing push technology on WebSocket. What is so revolutionary about that? Well, after more than 20 years of stateless-web based on stateless-request-paradigm, we finally have web applications with real-time, two-way connections where both clients and servers can initiate communication , Allowing them to freely exchange data. . This is in contrast to the typical web response paradigm, where the customer always initiates communication. Additionally, it is all based on an open web stack (HTML, CSS and JS) running on standard port 80.
One could argue that Flash and Java as Apple we have had for years – but in fact, they were sandboxed environments using the web as a transport protocol to be delivered to the customer. In addition, they were run in isolation and often operated on non-standard ports, which required additional permission and such.
With all its benefits, Node.js now plays an important role in the technology stack of many high-profile companies that rely on its unique benefits. The Node.js Foundation has consolidated all the best thinking of why enterprises should consider Node.js in a short presentation.
How does this work?
The core idea of Node.js: Use non-blocking, event-driven I / O to remain lightweight and efficient in the face of data-intensive real-time applications running through distributed devices.
This is a mouthful.
What this really means is that Node.js is not a silver bullet new platform that will dominate the web development world. Instead, it is a platform that caters to a particular need.
Does this really mean that Node.js is not a silver bullet new platform that will dominate the web development world. Instead, it is a platform that caters to a particular need. And it is absolutely necessary to understand this. You certainly do not want to use Node.js for CPU-intensive operations; In fact, using it for heavy calculations will eliminate almost all of its advantages. Where the node really shines is in building increasingly scalable network applications, as it is capable of handling a large number of connections simultaneously with high throughput, which is equivalent to high scalability.
How it works under-hood is very interesting. Compared to traditional web-serving technologies where each connection (request) produces a new thread, the system is taking RAM and eventually max-out on the amount of available RAM, Nod.js works on a single-thread , Using non-blocking I /. Hey call, this event allows to support thousands of concurrent connections held in loop.
A quick calculation: Assuming that each thread is potentially with 2 MB of memory, running on a system with 8 GB of RAM allows us theoretically a maximum of 4,000 concurrent connections (a calculation taken from Michael Abernethy’s article ) Just puts on “what is a node”. .js? ”, Published on IBM Developerware in 2011; Unfortunately, the article is no longer available), plus the cost of context-switching between threads. The scenario you usually deal with with traditional web-serving techniques. To avoid all of that, Node.js achieves scalability levels greater than 1M concurrent connections and 600k concurrent webscat connections.
Of course, there is the question of sharing the same thread among all customer requests, and this is a potential disadvantage of writing NODGGS applications. First, heavy computation can choke a single thread of a node and cause problems for all clients (more on this later) because incoming requests will be blocked until computation is completed. Secondly, developers really need to be careful not to allow core (topmost) bubbling up to the Node.js event loop, which will end the instance of Node.js (effectively crashing the program).
The technique used to avoid bubbling exceptions on the surface is passing errors to the caller in callback parameters (instead of throwing them, like other environments). Even if some unregistered exceptions manage to bubble up, tools have been developed to monitor the Node.js process and perform the necessary recovery of the crashed instance (although you can probably find the current state of the user session Will not be able to recover), is the most common Forever module, or using a different approach with external system tools upstart and monitor, or even just upstart.
Npm: node package manager
When discussing Node.js, one thing that definitely should not be skipped is the built-in support for package management using NPM, which comes by default with every Node.js installation. The idea of the NPM module is similar to the Ruby Gems: a set of publicly available, reusable components, available through an online repository through easy installation, with versioning and dependency management.
A complete list of packaged modules can be found on the npm website, or accessed using the npm CLI tool that automatically updates Node.js. Is installed with. The module ecosystem is open to everyone, and anyone can publish their own modules that will be listed in the NPM repository.
Some of the most useful npm modules today are:
Express – Express.js – or simply Express – a Sinatra-inspired web development framework for Node-JS, and the de-facto standard for most nodes out there today.hapi – a very modular and simple to use configuration-focused framework for building web and services applications Connect – Connect is an extensible HTTP server framework for Node.js, which provides a collection of high-performance “plugins” known as middleware; Aadhaar serves as the foundation for the Express.
socket.io and sockjs – server-side components The components of the two most common websock components are there today.
Pug (formerly Z) – One of the popular templating engines, inspired by HAML, which is a default in Express.js.
Mongodb and Mongoose – MongoDB wrapper to provide API for MongoDB object database in NOD.js
Redis – Redis Client Library.
Forever – Probably the most common utility to ensure that a given node script runs continuously. Processes its Node.js into production due to any unexpected failures.
Bluebird – A full-featured Promise / A + implementation with exceptionally good performance
the list goes on. There are tons of really useful packages available to all (no offense to those that I have left here).
Examples of how Node.js should be used
Chat is the most specialized real-time, multi-user application. From IRC (back in the day), Node.js has the ability to implement everything today, with WebSockets running over standard port 80s, through multiple proprietary and open protocols running on non-standard ports.
The chat application is actually the sweet-spot example for Node.js: it is a lightweight, high-traffic, data-intensive (but low processing / computation) application that runs on distributed devices. It is also a great use-case for learning, as it is simple, yet it encompasses most of the paradigms you would ever use in a specific Node.js application.
Let’s try to show how it works.
In the simplest example, our website has a single chatroom where people come in and can exchange messages in a one-to-many (actually all) fashion. For example, suppose there are three people associated with our message board on the website.
On the server-side, we have a simple Express.js application that implements two things:
A GET / request handler that serves a webpage with a message board and a ‘send’ button to initiate new message input, and
A WebSocket server that listens for new messages emitted by the WebSocket client.
On the client-side, we have an HTML page that sets some handlers, one for the ‘send’ button click event, which picks up the input message and sends it to WebSocket, and another that listens to newly arrived messages Is on the WebSocket client (that is, messages sent by other users, which the server now wants to display to the client).
What happens when a client posts a message:
The server-side component of the WebSocket connection receives the message and forwards it to all other connected clients using the broadcast method.
All clients receive the new message as a push message via the WebSocket client-side component running within the web page. They then pick up the message content and update the web page by adding a new message to the board.
This is the simplest example. For a more robust solution, you can use a simple cache based on the Redis store. Or in an even more advanced solution, a message queue to handle the routing of messages to customers and a more robust delivery mechanism that can cover the loss of temporary connections while offline or to store messages for registered customers . But regardless of the improvements you’ve made, Node.js will still be operating under the same basic principles: reacting to events, handling multiple concurrent connections, and maintaining fluidity in the user experience.
For example, if you are using Rails, you would convert from JSON to a binary model, then backbone.js, Angular.js, or even as plain JIV AJAX as data, when consumed by HTTP But will expose them back as JSON. Makes calls With Node.js, you can simply expose your JSON objects with the REST API for the client to consume. Additionally, you don’t have to worry about converting between JSON and whatever while reading or writing from your database (if you’re using MongoDB). In short, you can avoid the need for multiple conversions by using a uniform data numbering format across clients, servers, and databases.
If you are receiving large amounts of concurrent data, your database can become a bottleneck. Node.js can easily handle concurrent connections themselves, as shown above. But because database access is a blocking operation (in this case), we are in trouble. The solution is to accept the customer’s behavior before the data is truly written into the database.
With that approach, the system maintains its accountability under a heavy load, which is particularly useful when the client does not require a confirmed confirmation of a successful data write. Typical examples include: logging or writing of user-tracking data, processed in batches and not used until later; Also operations that do not need to be immediately mirrored (such as updating the ‘Like’ count on Facebook) where finally concurrency (so often used in the NoSQL world) is acceptable.
The data is queued through some kind of caching or message queuing infrastructure – such as RabbitMQ or ZeroMQ – and digested by a separate database batch-write process, or written deep into a better performing platform for such tasks Processing counts backend services. Similar behavior can be implemented with other languages / frameworks, but not on the same hardware, with the same high, maintain throughput.
In more traditional web platforms, HTTP requests and responses are treated as isolated phenomena; In fact, they are actually streams. This observation can be used to build some cool features in Node.js. For example, it is possible to process files while they are still being uploaded, because the data comes through a stream and we can process it in an online fashion. This can be done for real-time audio or video encoding, and proximity between different data sources.
Node.js is easily employed as a server-side proxy where it can handle large amounts of simultaneous connections in a non-blocking manner. This is particularly useful for different services with different response times, or for collecting data from multiple source points.
An example: consider a server-side application communicating with third-party resources, pulling in data from various sources, or storing assets such as images and videos for third-party cloud services.
Although dedicated proxy servers exist, it may be useful to use a node instead if your adjacent infrastructure is non-existent or if you need a solution for local development. By this, I mean that you can create a client-side app with a Node.js development server for the property and forward API requests, while in production you can use a dedicated proxy service (nginx, HAProxy, etc. ) Will handle such conversations with. .)
Brokerage – Stock Trader Dashboard
Let’s go back to the application level. Another example where desktop software dominates, but can easily be replaced with a real-time web solution, is brokers’ trading software, which is used to track stock prices, perform calculations / technical analysis, and create graphs / charts. Is done for.
Switching to a real-time web-based solution will allow brokers to easily switch to workstations or working locations. Soon, we can start seeing them on the beach in Florida .. or Ibiza .. or Bali.
Application Monitoring Dashboard
Another common use-case in which node-with-web-socket fits perfectly: tracking website visitors and viewing their interactions in real time.
You can collect real-time statistics from your user, or take it to the next level, by starting a targeted conversation with your audience from your channel when you reach a specific point in your funnel. (If you are interested, this idea is already being produced by CANDDi.)
Imagine if you knew what your visitors were doing in real time, you could improve your business – if you could imagine their interactions. With real-time, two-way sockets of Node.js, you can now.
Node.js can be used
Server-side web application
Node.js with Express.js can also be used to build classic web applications on the server-side. While it is possible, this request-response pattern in which Node.js will move around the rendered HTML is not the most typical use-case. Arguments have to be made for and against this view. Here are some facts to consider:
Crawlers receive a fully rendered HTML response, that is, Node.js. Is far more SEO-friendly than a single page application or WebShock app running on top of.
Any CPU-intensive computation will block Node.js accountability, so a threaded platform is a better approach. Alternatively, you can try to complete the calculation [*].
Using Node.js with relational databases is still quite a pain (see below for more details). If you are trying to do relational operations then do yourself a favor and choose another environment like Rails, Django, or ASP.Net MVC.
Heavy Serial-Side Computing / Process
When it comes to heavy computation, Node.js is not the best platform around. No, you definitely do not want to create a Fibonacci computing server in Node.js. In general, all throughput benefits are announced in any CPU intensive operation, with the node providing its own event-driven, non-blocking I / O model as any incoming requests will be blocked, while The thread is occupied with your number-crunching — assuming that you are trying to run your own computations in the same node instance with which you are requesting.
As stated earlier, Node.js is single-threaded and uses only a single CPU core. When it comes to adding consistency to multi-core servers, there is some work being done by the node core team as a cluster module [ref: http://nodejs.org/api/cluster.html]. You can also easily run multiple Node.js server instances via nginx behind a reverse proxy.
With clustering, you should still load all heavy computations for background processes written in an environment more suitable for that, and communicate them through a message queue server such as RabbitMQ.
Even though initially your background processing can be run on the same server, such an approach has the potential for much scalability. Those background processing services can be easily distributed across different worker servers without the need to configure the load of front-facing web servers.
Of course, you will use the same approach on other platforms as well, but with Node.js you will get the high per second / second throughput that we have talked about, as each request handles a small task very quickly and efficiently. is done.
in this matter:
res.statusCode = 200
We set the StatusCode property to 200 to indicate a successful response.
res.setHeader (‘Content-Type’, ‘text / plain’)
And we close the response, adding the contents as an argument end ():
res.end (‘Hello World \ n’)
Node.js Frameworks & Tools
Node.js is a low-level platform. To make things easier and exciting for developers, thousands of libraries were built by the community on Node.js.
Why You Should Use It For Enterprise Software
Node.js is a super-powerful, ultra-lean, lightweight JS based runtime application platform that performs JS code beyond the browser and serves JS everywhere.
This can be extended to employing third-party modules to develop feature-rich web applications for enterprises because of the vast aura seen around it.
Node.js, with over a billion downloads every week, has become the most prominent open-source platform ever.
Node.js rose to fame as a first-class citizen applying push technology in the creation of real-time apps, microservices, and IoT. Most enterprises favor NodeJS for mobile and web app development.
Reason for choosing Node.js for enterprise apps
The reason behind the widespread popularity and global acceptance of Node.js are its striking hallmarks and significant advantages. Node JS for the enterprise application includes and demands bulk input-output services querying the database.
Any programming language will provide you with some reasons to choose Node.js over others. Node.js stands out in its efficiency for developing easily scalable applications.
Its progressive-graph programming techniques for producing better tooling and complex applications make Node.js an edge.
This approach collectively helps to build applications into smaller services. The enterprise app ideally starts with MVP and develops applications employing a microservice architecture to provide scalability by compiling small portions.
Single-function modules can be developed to operate independently with a clean-designed user-interface. It enhances agile intelligence and DevOps within companies.
Many tech giants prefer to build small units (microservices) that are built together to develop a large application. Developers are given freedom to write code for different sections of the app in different languages and from anywhere at the same time.
Node.js basically enables you to design highly scalable and reliable microservices-based web apps by breaking them into smaller units.
Why is Node.J becoming popular with enterprise?
Many more things we can discuss in next blog thank you all