How to reduce or eliminate 502 errors on your WordPress or PHP website

Common Causes of 502 Bad Gateway Errors

The 502 Bad Gateway error is an HTTP status code that indicates that one server on the internet, while acting as a gateway or proxy, received an invalid response from the other server further upstream. This is a common error that occurs when a server receives an invalid response from another server. It can be caused by a variety of factors, such as an overloaded server, an incorrect proxy configuration, or an incorrect server address.

Network Issues

Network issues can be a common cause of 502 Bad Gateway errors. This can include a poor connection between the client and the server, or an interruption of the network connection. It can also be caused by an issue with the DNS server, such as a misconfigured DNS record, or an issue with the routing table.

Server Issues

Server issues can also cause a 502 Bad Gateway error. This can include an overloaded server, a misconfigured server, or an issue with the server’s software or hardware. It can also be caused by a server outage, or an issue with the server’s firewall or security settings.

Software Configuration Issues

Software configuration issues can also cause a 502 Bad Gateway error. This can include an incorrect proxy configuration, an incorrect server address, or an incorrect port number. It can also be caused by an issue with the application or web server software, such as a missing or misconfigured module, or an issue with the application’s configuration file.

Here is a checklist of things you can check, update and tweak to eliminate 502 errors on your website:

Check your .htaccess file for errors.

there are several website you can use to check your htaccess file for problems.

• The W3C Markup Validation Service: https://validator.w3.org/
• The Apache Software Foundation’s .htaccess Tester: http://htaccess.madewithlove.be/
• The HTACCESS Checker Tool: https://www.htaccesschecker.com/
• The Apache htaccess Checker: https://www.htaccesstools.com/apache-htaccess-checker/
  

Check your PHP version and make sure it is up to date.

Pros

Upgrading your PHP version can bring a host of benefits, such as improved security, enhanced performance, and better compatibility with newer technologies. With a newer version of PHP, you’ll benefit from new features and bug fixes that can make your code more efficient and secure. Additionally, a newer version of PHP can help you better integrate with other software and services, such as databases and APIs.

Cons

Although upgrading to a newer version of PHP has many benefits, it also comes with some risks. The biggest risk is that upgrading to a newer version of PHP may break existing code or applications. If you have existing code or applications that rely on the version of PHP you currently have, they may not work properly with a newer version. Additionally, some of the new features and bug fixes that come with a newer version of PHP may cause issues with existing code or applications.

Managing Risks

When considering an upgrade to a newer version of PHP, it’s important to take steps to manage the risks. First, you should test the newer version of PHP in a development environment to make sure it will work with your existing code and applications. Additionally, it’s important to back up your existing code and applications before upgrading so you can easily revert back to the old version of PHP if necessary. Finally, you should keep an eye on the release notes and bug reports for the new version of PHP, as these can help you identify any potential issues before they become a problem

Check for any plugin or theme conflicts.

When troubleshooting a WordPress website, it is important to check for any plugin and theme conflicts that may be causing the issue. Plugin and theme conflicts can be responsible for many types of problems, ranging from a website not loading properly to a plugin not functioning as intended. To check for plugin and theme conflicts, there are a few steps to follow.

Disable All Plugins

The first step in troubleshooting a plugin or theme conflict is to disable all of the plugins on the website. This can be done easily by navigating to the “Plugins” section of the WordPress dashboard and selecting the “Deactivate” option for each plugin. This will temporarily disable all of the plugins on the website, allowing you to test if the issue is linked to a particular plugin. If the issue is resolved after disabling all of the plugins, then the problem is likely caused by a plugin conflict.

Enable Plugins One by One

Once all of the plugins have been disabled, it is time to re-enable them one by one to find the culprit. Start by enabling the most recently installed plugin and check that the issue has not returned. If the issue has returned, then the plugin is likely the source of the conflict. If the issue has not returned, then continue enabling the remaining plugins one by one until the issue returns. Once the plugin causing the conflict has been identified, it can be deactivated and the issue should be resolved.

Switch Themes

If disabling plugins did not resolve the issue, then it is likely caused by a theme conflict. To test this, switch to a default theme such as “Twenty Seventeen” and check to see if the issue has been resolved. If the issue is resolved after switching themes, then the problem is likely caused by a conflict between the active theme and another plugin or theme.

Check for any database issues.

Checking a WordPress database for issues is an important part of maintaining a healthy WordPress website. It is important to regularly check for issues that can impact website performance or lead to data loss.

Verify Database Structure:

The first step to checking a WordPress database for issues is to verify the database structure. This involves checking the database tables for any errors or inconsistencies. It is important to ensure that every table has the correct columns, data types, and data length. Having the wrong structure can cause errors when trying to store or retrieve data.

Check for Corrupt Data:

The next step is to check the data in the database for any corrupt or invalid values. This can be done by running a query to check for any invalid values in the database. It is important to check the data in the database regularly as it can be corrupted by malicious software or user error.

Check for Unused Tables:

Finally, it is important to check the database for any unused tables. Unused tables can cause the database to become bloated and can cause performance issues. It is important to regularly check the database for any unused tables and delete them if necessary. This can help improve the performance of the website.

Check your server resources and make sure they are not being over utilized.

Monitoring Server Resources

The first step to making sure server resources are not being over utilized is to monitor them. This can involve tracking server performance metrics such as CPU, RAM, and disk usage. Many hosting providers provide tools to monitor these metrics, and there are also third-party monitoring software solutions available. By monitoring these metrics, it is possible to detect any unusual patterns or spikes in usage, which can indicate potential over utilization issues.

Optimizing Server Performance

Another way to ensure server resources are not being over utilized is to optimize the performance of the server. This could involve caching and compressing content, optimizing images, and disabling unnecessary plugins and services. It is also important to keep the server software and applications up to date to ensure they are running as efficiently as possible.

Monitoring Traffic

It is also important to monitor the traffic to the website to ensure it is not exceeding the resources available. If the website is receiving more traffic than the server resources can handle, it can lead to over utilization issues. This can be monitored using tools such as Google Analytics, which can provide insight into the amount of traffic the website is receiving and where it is coming from. This can help to identify any potential issues with over utilization.

Increase your PHP memory limit.

WordPress sites often require an increased memory limit in order to run efficiently. WordPress requires a minimum of 32MB memory limit, but many themes and plugins will require more. To increase the memory limit, you need to edit the wp-config.php file. This file can be found in the root folder of your WordPress site.

Firstly, you need to add the following code to the top of the wp-config.php file:

define( ‘WP_MEMORY_LIMIT’, ’64M’ );

The number 64M can be adjusted, depending on the amount of memory you wish to allocate to your WordPress site. Once the code has been added, save the wp-config.php file and upload it back to the root folder of your WordPress site.

Verifying Memory Limit

Once you have uploaded the edited wp-config.php file, you can verify that the new memory limit has been set. To do this, you can use a plugin such as WP Memory Limit or a plugin that displays phpinfo(). These  plugins will allow you to view the memory limit that is currently set for your WordPress site. If the new memory limit has been set successfully, you should see the updated value displayed in the plugin. You can then remove the plugin from your WordPress site, as it is no longer needed.

Disable or remove any unnecessary plugins.

Checking for Unnecessary Plugins

It is important to check for unnecessary plugins in order to keep your WordPress website running smoothly and securely. Unnecessary plugins can slow down your website, create compatibility issues, and even lead to security vulnerabilities. Fortunately, it is easy to check for and disable or remove any unnecessary plugins.

Check Your WordPress Dashboard

The first step is to check your WordPress dashboard for any unnecessary plugins. Most WordPress websites include several plugins that were installed as part of the initial setup or are needed for specific features. You can quickly review the plugins list to identify any plugins that are not needed. If you find any plugins that are not necessary, you can easily uninstall them.

Check Your Plugins Directory

The next step is to check your plugins directory and review all of the plugins that are installed. This will allow you to identify any plugins that are not needed and remove them. It is also important to check for any outdated plugins. Outdated plugins can increase the risk of security vulnerabilities, so it is important to update them or uninstall them if they are no longer needed.

Once you have identified any unnecessary plugins, you can easily disable or remove them. This will help to keep your WordPress website running smoothly and securely.

Try to use a caching plugin.

Server side caching is a process of storing website data on the web server so that the data can be quickly accessed when needed. This improves the performance of the website and reduces load time. In WordPress, server side caching can be managed to improve the management of resources on the website.

Benefits of Server Side Caching

Server side caching offers many benefits to WordPress websites. It reduces the load on the web server, which helps to improve the website performance. It also helps to reduce the amount of bandwidth used and improves the loading time of the website. Additionally, server side caching also helps to improve the user experience as the website loads faster.

Managing Server Side Cache in WordPress

Managing server side cache in WordPress is relatively easy. The first step is to install a caching plugin such as WP Super Cache or W3 Total Cache. These plugins provide an easy to use interface for managing the server side cache. Once the plugin is installed, it can be configured to the desired settings. The settings can be adjusted to increase the amount of caching and to set the time for which the cached data should be stored.

Contact your website host for assistance.

In the end you might have to get in contact with your website host for any of the above solutions.  

We understand that this blog might have been a bit overwhelming and technical for some readers. Is this a bunch of technical gibberish to you? Don’t worry, we’ve got you covered! Here at 613-840-5332, we provide real human help with website issues. We’ve been doing this for the past 20 years, so you can trust our expertise and commitment to customer experience. Our team is always here for you, so don’t hesitate to give us a call anytime.