10 Websocket Best Practices

Websockets are a powerful tool that can help you build real-time, interactive applications. However, as with any tool, there are certain best practices that should be followed in order to get the most out of them.

In this article, we’ll discuss 10 websocket best practices that will help you build better applications. By following these best practices, you can avoid common pitfalls and ensure that your applications are performant, scalable, and secure.

1. Use a WebSocket library

A WebSocket library will take care of the low-level details of communicating over a WebSocket connection, such as handling the initial handshake, sending and receiving data, and closing the connection. This means that you can focus on your application logic, without having to worry about the underlying implementation details.

There are many different WebSocket libraries available, for a variety of programming languages. Some popular options include:

– Autobahn (Python)
– Socket.IO (JavaScript)
– Pusher (PHP)
– Faye (Ruby)

When choosing a WebSocket library, make sure that it is well maintained and has good documentation. It should also be compatible with the programming language and web framework that you are using.

2. Secure your WebSockets

WebSockets are a duplex communication protocol, meaning they allow for full-duplex, or two-way, communication. This is in contrast to the half-duplex, or one-way, communication of HTTP. Because WebSockets allow for two-way communication, they open up a whole new world of potential attacks that didn’t exist with HTTP.

For example, an attacker could use a WebSocket to inject malicious JavaScript into a web page, which would then be executed by the victim’s browser. Or, an attacker could use a WebSocket to launch a denial-of-service attack by flooding the server with requests.

To prevent these kinds of attacks, it’s important to secure your WebSockets with SSL/TLS. By encrypting the traffic between the client and server, you can be sure that only authorized parties can access the data being exchanged.

3. Don’t use WebSockets for chatty protocols

When you have a chatty protocol, it means that there is a lot of small data being sent back and forth between the client and server. This can quickly add up to a lot of data being transferred, which can cause performance issues.

Instead, WebSockets should be used for protocols where there is a need for real-time communication, but the data being exchanged is not too chatty. For example, a good use case for WebSockets would be a stock ticker application where you need to get the latest stock prices as soon as they are available.

4. Consider the network topology of your application

Websockets are designed for communication between two devices that are connected to the same network. However, in many cases, applications need to communicate across different networks. For example, an application running on a phone might need to communicate with an application running on a server in a different country.

If you’re using websockets in this type of scenario, it’s important to consider how the different networks will interact with each other. In particular, you need to be aware of potential security risks that could arise from connecting different networks.

One way to mitigate these risks is to use a VPN (virtual private network) to connect the different networks. This will create a secure connection between the networks and help to protect the data that is being exchanged.

5. Be aware of browser limitations

Different browsers have different levels of support for websockets. For example, Internet Explorer 10 has very limited support for websockets compared to other browsers like Google Chrome or Mozilla Firefox. This can cause problems if you’re trying to use websockets in a cross-browser environment, because certain features might only work in certain browsers.

To avoid these issues, it’s important to test your websocket implementation in all the browsers you plan to support, and make sure that all the features you need are available. You may also need to provide fallbacks for older browsers that don’t support websockets.

6. Avoid blocking operations in JavaScript

Blocking operations in JavaScript can cause problems because they prevent the websocket from receiving messages. This can lead to missed messages, and if the blocking operation takes a long time to complete, it can even cause the browser to become unresponsive.

To avoid these problems, you should use asynchronous programming techniques whenever possible. For example, instead of using the synchronous XMLHttpRequest API, you should use the asynchronous Fetch API.

If you do need to use blocking operations, make sure to break them up into smaller pieces so that they don’t block the websocket for too long.

7. Keep an eye on memory usage

Websockets are constantly sending and receiving data, which means they can quickly use up a lot of memory. If you’re not careful, this can lead to your server running out of memory and crashing.

To avoid this, it’s important to monitor your websocket connections and make sure that they are not using more memory than they should be. There are a few ways to do this, but one of the simplest is to use the ws module’s built-in memoryUsage() function.

This function will return an object containing information about the current memory usage of your websocket connection. You can then use this information to decide whether or not you need to take action to reduce memory usage.

For example, you might want to consider disconnecting clients that are using too much memory, or limiting the amount of data that they can send and receive.

8. Use TLS to secure all connections

Websockets are often used to transmit sensitive data, such as financial information or personal messages. If this data is not encrypted, it can be intercepted and read by anyone who is monitoring the connection.

TLS (Transport Layer Security) is a protocol that provides encryption and authentication for communications over the internet. When TLS is used with websockets, it ensures that all data transmitted between the client and server is encrypted and cannot be read by anyone who is not supposed to have access to it.

To use TLS with websockets, you will need to obtain a digital certificate from a trusted Certificate Authority. Once you have obtained a certificate, you will need to configure your websocket server to use it.

9. Protect against cross-site request forgery (CSRF) attacks

CSRF attacks exploit the fact that browsers automatically send cookies with every request to a website. This means that if a user is logged into a site, and they visit a malicious site, that malicious site can send requests to the first site that include the user’s cookies. These requests will be executed as if they came from the user themselves, which can allow the attacker to do things like make purchases or change account settings.

To protect against CSRF attacks, it’s important to ensure that websocket connections are only ever made over HTTPS, and that the browser verifies that the server’s certificate is valid. Additionally, developers should consider implementing a same-origin policy for their websockets.

10. Monitor and log WebSocket traffic

Websockets are a new technology, and as with any new technology, there are bound to be security vulnerabilities that have not been discovered yet. By monitoring and logging WebSocket traffic, you can quickly detect when something unusual is happening and take appropriate action.

Additionally, Websockets can use a lot of bandwidth, so it’s important to keep an eye on your usage and make sure you’re not exceeding your limits. Monitoring and logging will help you do this.

Finally, if you ever need to troubleshoot an issue with your Websocket connection, having logs will be invaluable.