What does error establishing a Redis connection and how to fix?

If you are updating your WordPress plugin and see “Error establishing a Redis connection” on your WordPress site.

You are angry about your site being down due to the Redis plugin. I have a solution to this problem: “error establishing a Redis connection in the plugin.”

I recommend reading the solution guide; I read multiple blogs and insights from various expert sources and found the expert solution to this problem, especially focusing on plugin updates within WordPress environments.

Understanding the Core Issues (Error establishing a Redis connection)

Redis, an advanced in-memory data structure store, is pivotal for enhancing website performance through caching. However, the integration of Redis with WordPress can be challenging. Key challenges often stem from plugin updates or misconfigurations, leading to the dreaded “Error establishing a Redis connection.” The root causes are generally two-fold:

Plugin Compatibility

Updates to the Redis Object Cache plugin, particularly version 2.3.0, have introduced compatibility issues, especially on shared Redis databases across sites on Ubuntu 18.04 and 20.04 stacks.

Increased Load

WordPress version 6.3 has been identified to impose a significant load on the object cache, exacerbating the issue on servers hosting websites with extensive Redis Store usage.

Step-by-Step Guide to Fix “Error Establishing a Redis Connection” in WordPress

Step 1: Increase Redis Timeouts

1. Locate Your user-configs.php File: This file is part of your WordPress site’s configuration files. You might need FTP access or a file manager tool provided by your hosting service to access it.
2. Modify Timeouts: Add the following lines to your user-configs.php file. These lines increase the Redis connection and read/write timeouts, helping to prevent the error.

// Increase Redis connection and read/write timeouts
define('WP_REDIS_TIMEOUT', 2); // Connection timeout in seconds
define('WP_REDIS_READ_TIMEOUT', 2); // Read/write timeout in seconds

Note: Adjust the timeout values based on your needs. The default is 2 seconds, but your site may require more.

Read about more the redis cache:

https://github.com/rhubarbgroup/redis-cache/blob/develop/INSTALL.md#3-configuring-the-plugin

Step 2: Upgrade to a Dedicated Redis Database (For Ubuntu Users)

Ubuntu 18.04 or 20.04 Users:

Consider Upgrading to Ubuntu 22.04: This is recommended for users on Ubuntu 18.04. Upgrading provides better compatibility and performance with WordPress and Redis.

Enable a Dedicated Redis Database: For Ubuntu 20.04, ensure each site uses its own Redis database. This can be done by toggling object caching off and on again in your site’s settings.

How to Toggle Object Caching:

1. Access Your Site’s Control Panel: Find the object caching option.
2. Toggle Off, Then On Again: This action clears the current Redis cache and enables the use of a dedicated database.

Important: Perform this step during low-traffic times to minimize impact on your site’s visitors.

Step 3: If Problems Persist, Increase Server Resources

1. Allocate More RAM to Redis: Instructions can typically be found in your hosting provider’s knowledge base or by consulting Redis documentation.
2. Consider Upgrading Your Server: If your website is still experiencing issues, a server upgrade to increase available RAM may be necessary.

Conclusion

I’m sure, By following these steps, WordPress users can effectively address and resolve the “Error establishing a Redis connection” issue, leading to improved site performance and stability. These steps not only solve the immediate problem but also position your site for better performance and reliability in the long run, ensuring a smoother, more user-friendly experience for your visitors. If you need more clarification on any step or need further assistance, consider contacting a professional or your hosting provider for support.