Today we decided to tell you about one of these technologies - the WebSocket protocol. We will explain how it works and its advantages in simple examples.
How Did the Internet Work Before WebSocket?
Before the WebSocket advent, the client (browser) had to send a request to get new information from the server, and the server sent a response. Without the request, there was no response. That is, no page update - the server could not send anything itself. This model is still working on the web but in fewer quantities.
For example, the user received a message on the website. For the client (browser) to know about it, it had to poll the server at some intervals to see if there was any new data.
There was another option. Browsers found out about the new data only when users interacted with the website: when they navigated to other pages, manually refreshed a tab, or re-opened the website.
There were disadvantages to this approach:
- Superfluous network load. The client (browser) had to constantly send requests to the server, even if there was no new information.
- The overhead of establishing a new connection with each request/response. This also consumed some time. Going forward, we note that the connection is established once and kept open in WebSocket, so there is no additional overhead.
- Low data update rate. The client (browser) couldn't get the data as soon as it appeared on the server. New data reached the browser only after the server had received the request. If it was important to get the data as soon as possible, the browser could contact the server more frequently, for example, once every 0.5 seconds. However, this placed an additional load on the network and the server, which had to conduct and process many requests.
On the other hand, WebSockets allow for an always-on connection so that the server can send new data to the client without waiting for a request. This interactivity eliminates the above disadvantages. To see the benefits of WebSocket, let's compare it with HTTP.
How Does WebSocket Differ From HTTP?
Before the advent of Web Sockets, the primary protocol was and still remains HTTP. The HTTP protocol is unidirectional. After the request-response cycle, the connection is closed. Any subsequent request establishes a new connection to the server: as many requests as there are connections. It wasn't a problem for static content like an informational article on a website. But you need to refresh the page manually to find out about changes in interactive content (such as a new message in an online chat, comments, or push notifications).
The data transfer process is also somewhat delayed. This is due to the overhead of establishing a new connection for each request/response, as well as the network and server load due to the abundance of periodic requests.
Pure HTTP protocol is used less now as HTTPS replaced it. It's not a standalone protocol but an add-on to HTTP that allows you to encrypt your data.
The first version of the WebSocket protocol appeared in 2009. Already in 2011, it received RFC (Request for Comments) status. It was recognized as a standard widely used on the World Wide Web. Today, WebSocket technology is used in all mobile, desktop, and server devices.
The WebSocket protocol is bidirectional, full-duplex, meaning it can both receive and transmit information. A WebSocket does this many times over a single open connection. This connection also has a higher speed than HTTP.
Web sockets also have the ability to encrypt data in transit. This is done using the WSS protocol. If transmitted data is not encrypted, it becomes an object of attraction for such threats as unauthorized access to the client by third parties or the use of malware. Special add-on data transfer protocols encrypt information on the sending side and decrypt it on the receiving side, leaving it encrypted for any intermediaries. This adds a secure transport layer.
To illustrate the differences between HTTP and WebSocket, let's take a chat room example. For users to receive new messages, the browser would periodically ask the server if there were new messages for the user. Each such request would establish a new connection and cause unnecessary network load.
How Does WebSocket Work?
On the Internet, there are strict rules for transferring data between client and server (TCP/IP protocol stack), but there are no strict rules on establishing a connection and structuring the message transmitted. And this affects speed.
To establish a connection, WebSocket uses the open handshake method. The client precedes the sending/receiving of messages with a preliminary request, in which the client and the server "agree" to use web sockets. This is the "handshake". The structure of such a request is similar but slightly different from HTTP. The client and server then exchange data within that connection.
Web sockets also have additional extensions that supplement and extend the protocol. For example, there is an extension for data compression. Or the ability to transfer data in SOAP, WAMP, or XMPP protocols. For these extensions to work, they need to be supported by both the server and the client.
Advantages and Disadvantages of Using WebSocket
WebSocket is a convenient technology for transmitting dynamically updated data. Its implementation allows developers to reduce the network and server hardware load and accelerate the website's work. Now, lets discuss WebSocket advantages and disadvantages in detail.
Advantages of WebSocket
Here are the main WebSocket advantages:
- Full-duplex communication. WebSocket supports full-duplex communication, allowing data to be sent and received simultaneously. This makes it ideal for applications that require interactive, real-time data exchange. These are online gaming, collaborative tools, and live chats.
- Low latency. Once a WebSocket connection is established, data can be transmitted with minimal delay.
- Reduced overhead. WebSocket connections remain open, eliminating the need for repetitive HTTP requests. This reduces the overhead associated with establishing and tearing down connections. This leads to more efficient use of server and network resources.
- Scalability. For applications with many concurrent users, WebSocket can be more scalable than alternatives like Long Polling. Persistent connections allow for better resource management, particularly when using load balancers and other scaling strategies.
- Broad support. WebSocket is widely supported by modern web browsers and platforms, making it a versatile choice for web-based and mobile applications. Its standardized protocol ensures compatibility and ease of integration across different environments.
As you can see, the benefits of WebSockets are sufficient. By the way, if you need to augment your team with devs profound in React JS, WebSockets, and SSE, you can hire React JS developers at MaybeWorks.
Disadvantages of WebSocket
Here are the main disadvantages of WebSockets:
- Complexity. This is one of the main WebSocket disadvantages. Implementing WebSocket requires a more complex server and client architecture compared to simpler technologies like HTTP. Developers need to handle connection management, error handling, and security considerations more carefully.
- Resource consumption. Keeping numerous WebSocket connections open can consume significant server resources. Each active connection requires memory and processing power, which can become a bottleneck if not managed properly.
- Browser support variability. Although WebSocket is supported by most modern browsers, older browsers, and some environments may not fully support the protocol. This can limit its applicability in scenarios where broad compatibility is required. Browser support variability is one of the main WebSocket limitations.
- Connection rejection without notifications. Sometimes it is necessary to introduce additional communication mechanisms between the client and the server to understand whether the client is responding.
- Changing the network by the client. The server will not receive information about the address change if the client does not close the connection when reconnecting to another network.
Yes, WebSocket drawbacks can ruin the project in the case of inexperienced developers. This is why it is necessary to hire Node.js developers with sufficient experience in WebSockets to overcome these WebSockets disadvantages.
When to Use and When Not to Use WebSocket
WebSocket is suitable when you need real-time data updates and the ability to deliver messages to the client. Here are a few examples of projects where WebSocket should be used:
- Trading applications with volatile quotes or real-time prices: sales platforms, exchanges
- Gaming applications
- Chats
- Push notifications
- Social media
- Device management in the IoT (using the WAMP sub-protocol)
- Online games, especially multiplayer
- Collaborative web applications
- Online auctions and bidding platforms
- Live streaming
When you need immutable data that is retrieved only once to be processed by an application, it's better to use the HTTP protocol rather than WebSocket. This could be, for example, an article page. Once published, the article changes very little, so there is no point in using a persistent connection to display it.
Also, the HTTP protocol is preferable if we don't want to keep a connection for a certain time or to reuse a single connection to transmit data. These are, for example, situations where the server has to give all the data for a form in one response.
Alternatives to WebSocket
We have discussed the pros and cons of WebSockets with you. WebSockets are generally preferred for applications requiring full-duplex communication and low latency, such as gaming or collaborative tools. Now, it is time to discuss its alternatives: Long Polling and SSE.
Long Polling
Long Polling is a method used to achieve near-real-time communication by keeping a connection open until the server has new information to send. Here’s how it works in practice:
- Mechanism. In Long Polling, the client makes a request to the server. If the server doesn’t have data available, it holds the request open until new data arrives. Once data is available or a timeout occurs, the server responds, and the client immediately initiates a new request.
- Performance considerations. This approach can simulate real-time updates but isn’t as efficient as WebSockets. Each new request involves the overhead of establishing a connection, which can lead to increased latency and server load. Long Polling also introduces delays since the client must wait for a new response after each request.
- Use cases. Long Polling is suitable for applications where WebSocket pros and cons can't be balanced. It’s often used in scenarios like chat applications or live notifications where real-time data is needed but the overhead of WebSocket implementation isn’t justified.
Long Polling can be a fallback option when WebSocket isn’t feasible. It offers a simpler, though less efficient, method for real-time communication.
Server-Sent Events (SSE)
Server-Sent Events (SSE) is a technology for one-way communication from the server to the client. Here’s a detailed look:
- Mechanism. SSE establishes a persistent HTTP connection from the client to the server. The server sends updates as they become available, and the client receives these updates automatically. Unlike WebSockets, SSE only supports server-to-client communication, not the other way around.
- Performance considerations. SSE is more efficient for sending continuous updates from the server compared to Long Polling. It maintains a single connection, reducing the overhead of repeatedly opening and closing connections. SSE also supports automatic reconnection and event IDs, which can help manage connectivity issues and track messages.
- Use cases. SSE is ideal for applications where the client only needs to receive updates, such as live news feeds, stock price updates, or real-time notifications. It’s simpler to implement than WebSockets for these use cases but may not be suitable if two-way communication is required.
SSE is best suited for scenarios involving continuous server-to-client updates. It provides a more streamlined approach compared to Long Polling but lacks bidirectional communication. If you need to augment your team, we have Typescript developers for hire.
WebSocket vs. REST
WebSockets and Representational State Transfer (REST) are both protocols used in web applications, but they have different characteristics and use cases. Let's discuss them:
- Communication model. WebSockets provide a full-duplex, bidirectional communication channel between a client and a server, allowing real-time communication in both directions. Conversely, REST follows a client-server model where the client sends requests to the server, and the server responds with the requested data. REST is typically based on the request-response pattern, while WebSockets enable continuous communication without the need for repeated requests.
- Real-time communication. WebSockets are ideal for real-time applications where immediate updates and real-time data exchange are required, such as chat applications, gaming, or live streaming. On the other hand, REST is typically used for request-response scenarios where the client requests data from the server and receives a response, which may not be real-time.
- Scalability. WebSockets can be more scalable in certain scenarios due to their ability to maintain persistent connections and push updates to clients without the need for repeated requests. On the other hand, REST may require multiple requests from clients to get updates, which can result in increased overhead and reduced scalability.
- Protocol overhead. WebSockets have lower protocol overhead than REST, as they use a single connection that remains open for the duration of the session, reducing the need for repeated handshakes and headers. REST, on the other hand, requires separate HTTP requests and responses for each communication, which can result in higher overhead in terms of bandwidth and latency.
- Caching and caching mechanisms. REST relies on standard HTTP caching mechanisms, such as ETag and Last-Modified headers, which can be used for caching responses and improving performance. WebSockets do not have built-in caching mechanisms, as they are designed for real-time, dynamic communication.
- State management. REST is stateless, meaning that each request from a client must contain all the necessary information for the server to understand and process the request. WebSockets, on the other hand, maintain a persistent connection and can maintain stateful communication between the client and the server, allowing for more complex interactions and workflows.
- Client compatibility. REST APIs can be accessed from various clients, including web browsers, mobile apps, and other servers, using standard HTTP methods. On the other hand, WebSockets require client-side support for the WebSocket protocol, which may not be available in all clients or require additional implementation effort.
- Security. Both REST and WebSockets can be secured using encryption protocols such as HTTPS and WSS (WebSocket Secure) to ensure secure communication between the client and the server. REST relies on standard HTTP security mechanisms. At the same time, WebSockets have their own security considerations, such as preventing cross-site scripting (XSS) and cross-site request forgery (CSRF) attacks on WebSocket connections.
So, WebSockets are well-suited for real-time applications that require continuous communication and low-latency updates. At the same time, REST is typically used for request-response scenarios and may be more suitable for applications that require caching, statelessness, and wide client compatibility. The choice between WebSockets and REST depends on the specific requirements of the application and the nature of the communication needed.
MaybeWorks - a Reliable IT Staff Augmentation Provider with Skilled WebSockets Developers
One of the last projects where our developers assisted in project development using WebSocket was a Zoom-like application that allows users to create rooms and have video calls with their friends/partners. The critical difference was that this project was more aimed at small and thematic groups who wanted to play some built-in games or just have fun talking to each other.
This client hired 2 MaybeWorks full-stack developers for his small team to assist in building the project. They:
- Developed the video chat based on the WebRTC using Twilio API
- Implemented Node JS of our API and socket server
- Rewrote the whole app on TypeScript
- Transferred all the data from MongoDB to PostgreSQL
Our developers worked with Typescript, NodeJS, Express, and WebSockets in the backend. They also worked with React and Twilio WebRTC API in the frontend.
As an IT staff augmentation provider, we allowed our client to get the required experts for Zoom-like app development quickly and effortlessly. Feel free to contact us right now!
FAQ
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Are WebSockets suitable for streaming video or audio?
Yes. However, they may not be the most efficient choice for high-bandwidth streaming needs. Protocols like WebRTC are often preferred for these applications due to their optimized handling of media streams. WebSockets can still be used if the streaming requirements are not too demanding.
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What are the alternatives to WebSockets for real-time communication?
Alternatives to WebSockets include WebRTC, Server-Sent Events (SSE), and HTTP/2. WebRTC is designed specifically for real-time media and peer-to-peer communication. SSE is suitable for server-to-client streaming of updates. HTTP/2 also supports multiplexed streams over a single connection. Each alternative has its own strengths and best-use scenarios.
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Are WebSockets secure?
WebSockets can be secure when used with proper configurations and practices. Using WSS (WebSocket Secure) ensures that data transmitted over WebSockets is encrypted, similar to HTTPS. However, security also depends on the implementation, including proper handling of authentication and validation. Without these measures, WebSockets can be vulnerable to attacks.
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What are the security considerations when using WebSockets?
It's important to use WSS to encrypt data and protect against eavesdropping. Implementing robust authentication mechanisms is crucial to prevent unauthorized access. Validating all incoming data to guard against potential attacks, such as cross-site WebSocket hijacking, is also important.
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How do WebSockets impact server scalability?
WebSockets maintain a persistent connection, which can consume server resources and potentially impact scalability. Each active WebSocket connection requires server memory and processing power, which can add up with a large number of users. To manage scalability, techniques such as load balancing and efficient resource management should be employed.
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Can WebSockets be used in mobile applications?
Yes. WebSockets are supported by most modern mobile platforms. They provide a way to maintain a continuous connection, which can be useful for applications that require instant updates. However, mobile network conditions and power consumption should be considered when using WebSockets.
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Can WebSockets reconnect automatically after a disconnection?
WebSockets do not have built-in automatic reconnection features.
