What is a 504 error and how do you fix it?

While browsing online, you may have come across a 504 Gateway Timeout Error or Error 504 when opening a web page. This error happens when a gateway or proxy server doesn’t receive a response quickly enough from the main server.  The delay causes the request to fail, resulting in an error.  

But what exactly does this mean, and more importantly, how can you fix it?  

In this article, we’ll break down what a 504 error is, why it happens, and how you can troubleshoot and resolve it. Whether you own a website or just need to access a webpage, understanding and fixing this error is helpful for a smooth online experience. Let’s dive in!  

What is error 504? 

A 504 error, also known as a Gateway Timeout error, occurs when a server acting as a gateway or proxy doesn’t receive a timely response from the main server. The main server hosts the data that needs to be retrieved to complete a client’s or browser’s request for website content. As a result, the user gets the 504 error message instead of the desired content. 

What causes a 504 Error? 

Before we tackle the causes of a 504 Error, let’s take a quick look at how websites work.  

A website is essentially a collection of files and resources that are sent to users through the internet. When you access a website in the browser, it requests the site’s files that’s stored in the server. The browser then uses the files to show the webpage.  

Sometimes, to make internet browsing more secure and efficient, proxy servers are used as a gateway to request and deliver information to and from the original servers. It acts as an intermediary between your computer and the internet. Proxy servers can hide your real IP address, adding more privacy to your online activities and protecting your network by filtering out harmful content. 

The 504 Error occurs when the original server or higher-level servers fail to provide the requested information to the proxy server within the allotted time.  

504 Gateway Timeout errors happen due to the following reasons: 

Server overload  

Compare a restaurant with too many customers to how your website works. If the kitchen (the server) can’t handle all the orders, some customers will wait too long, and some orders might not be fulfilled.  

Similarly, when a web server gets overwhelmed with too much traffic or too many requests, it can’t respond quickly enough, leading to a 504 error. This often happens during periods of high website traffic or if the server’s resources (like memory or processing power) are stretched too thin. 

DNS resolution failures  

DNS (Domain Name System) is like the phonebook of the internet. It helps your browser translate website names (like www.mywebsite.com) into the IP address of the server that holds the site’s data. The request for website information only happens after the DNS resolution, or the translation of website names into IP addresses.  

If the DNS server can’t find the correct IP address or is misconfigured, your request can’t reach the right server, causing a delay. If this takes too long, the server will time out, and you’ll see a 504 error. 

Faulty server configuration 

As mentioned, there are instances when servers are set up to communicate through proxy servers or security systems, like firewalls. These tools are meant to filter out unwanted traffic or speed up communication. However, if they malfunction or are misconfigured, they can block or slow down the connection between your device and the server. This miscommunication can cause the server to give up and throw a 504 error.  

Network congestion or slow server communication  

Just like a traffic jam on a busy highway, network congestion happens when too many data packets are trying to travel along the same route at the same time. This can slow down the communication between servers, and in some cases, it causes a delay that’s long enough to trigger a timeout. If one server can’t get the information it needs in time from another server, you’ll get a 504 error.  

How to fix a 504 gateway timeout error 

Now that you have a basic idea of what causes a 504 e  rror, let’s walk through the steps to fix it.  

1. Refresh the page or try a different browser 

Sometimes, the issue can be temporary or related to your browser. Start troubleshooting by refreshing the page to see if the error resolves itself. If not, clear your browser cache. It may hold outdated data that is interfering with the connection. You can also try accessing the website using a different browser, device, or internet service provider.  

2. Check server performance  

If the server is under heavy load, it may struggle to respond to requests, leading to a 504 error. You can use tools such as New Relic or Pingdom to determine if the server is overloaded. If you find that the server is overloaded, consider implementing strategies like load balancing or caching.  

Load balancing helps distribute incoming traffic across multiple servers, while caching stores frequently accessed data in a temporary storage location to reduce the load on the server.  

3. Check DNS settings  

Ensure your domain’s DNS records are correctly configured. They should be pointed to where your website is currently hosted. You can check this in your domain provider’s control panel or use DNS lookup tools.  

Look out for any changes in the configuration, especially when you are transferring your website from one service provider to another. Site transfers affect how you configure your DNS.  

Also, when alterations to your DNS settings are made, they need time to take effect, so it may cause temporary downtime or errors on your website. In these cases, waiting for around 90 minutes (average DNS propagation time) is the best course of action when resolving a DNS-related 504 error. 

4. Clear your DNS cache.  

Sometimes, your device or browser may be holding onto outdated DNS information. Aside from clearing your browser cache, try clearing your local DNS cache to force it to fetch fresh data. On Windows, you can do this by opening Command Prompt and typing ipconfig /flushdns.

On macOS, open Terminal and type sudo killall -HUP mDNSResponder.  

5. Check proxy settings  

If you’re using a proxy server such as Cloudflare to route traffic between your site and users, ensure the proxy is properly configured. Misconfigured proxies can lead to delays and timeouts. Test your site without the proxy to see if the 504 error goes away.  

6. Examine firewall rules  

Review your server’s firewall settings to ensure it’s not blocking legitimate traffic or causing delays. If you’re using a Cloudflare firewall, for example, check your security settings to make sure they’re not overly strict or misconfigured.   

7. Check timeout settings  

Review timeout settings in your web server configuration to make sure they aren’t too strict. Strict configuration means the time allowed before the error appears when no response is received is set too short. The server may disconnect before it can finish processing the request. Try setting it to 20 seconds or longer and see if it allows you to move past the error message. 

8. Check for scheduled maintenance or outages.  

If the error is affecting multiple users, check with your web hosting provider to see if they’re undergoing scheduled maintenance or if there are any ongoing outages that could be causing the problem.  

9. Contact your hosting service provider.  

If you’ve ruled out the issues on your end and the error persists, it might be a server-side problem that requires assistance from your hosting provider. Reach out to them and provide them with details like when the error occurred, the steps you’ve already taken, and any relevant logs you retrieved from your end.  

Best practices: How to prevent 504 error messages 

A 504 error is not just frustrating to experience as a web visitor but can also be disruptive for online business owners. This is why taking proactive steps to significantly reduce the chances of encountering it can save you resources in the long run.  

Here are some best practices to keep your website running smoothly and minimize the risk of server-related issues:  

Regular server maintenance and monitoring  

Regularly maintaining and monitoring your server helps ensure that it’s always running efficiently. This includes checking system logs, ensuring that resources (like CPU, RAM, and storage) are not maxed out, and making sure everything is up to date. Regular monitoring can help detect server issues before they escalate into bigger problems, like overloads or timeouts.  

Tools like New Relic or Pingdom can help you keep an eye on your server’s performance in real-time.  

Configuring server for increased traffic 

If you anticipate high traffic volumes, you should configure your server to handle large spikes in visitors without becoming overwhelmed. Websites with high traffic can easily overwhelm a single server, causing a 504 error when it fails to respond in time.  

You can use Cloudflare for load balancing to distribute traffic across multiple servers. You may also upgrade your hosting package for more resources to handle large numbers of requests. 

Keeping DNS up to date 

DNS resolution failures are a common cause of 504 errors, so it’s important to keep your DNS settings updated. Regularly review your DNS records, especially if you change hosting providers or move to a different server. Verify that your Name Servers, CNAME records, and A records are properly configured. 

Using Content Delivery Networks (CDNs) for redundancy  

A CDN is a network of distributed servers that store copies of your website’s static content, like images. By doing so, the main servers don’t work as hard to retrieve the data. Browsers will just fetch it directly from the stored copies when requested. This eases the load on the origin server, minimizing the chances of a 504 error, even during traffic spikes. You can use a reputable CDN provider like Cloudflare or Akamai to cache static assets. 

Updating software and plugins regularly  

Outdated software can bring problems like bugs and security issues that hurt server performance and communication with other servers. You might also run into problems with outdated plugins or extensions that conflict with your server setup, slowing things down. Regularly check for software updates for your server, website platform and plugins, and set up automatic updates to ensure compatibility within your server’s configuration.  

Choose the right domain and web hosting provider.  

Encountering 504 error messages on your website can be frustrating, especially if they happen frequently. Even short periods of downtime can significantly impact your business, from lost revenue to a damaged reputation.  

While the error typically points to server or network issues, understanding its causes and knowing how to troubleshoot it can help you get back on track quickly. By staying proactive and implementing the best practices outlined above, you can minimize the risk of these errors and avoid costly disruptions in the future. 

Selecting the right domain and hosting provider ensures reliable performance and provides tools to monitor and manage your site, reducing the risk of errors like the 504 Gateway Timeout. Domain.com provides you with a convenient UI for DNS monitoring, automatic platform updates, and plenty of resources to manage high traffic. Feel secure and confident that your website stays up even during peak hours. 

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