High Availability WordPress with HyperDB

James George
James George

One of the reasons why I have always been so enamored with WordPress is because of the limitless possibilities it has. It seems like if you know PHP and how to leverage data and control it, you can do almost anything. A WordPress database can hold just about any type of data, which has made it even more useful with the added capability of custom post types and custom fields. You can save all sorts of data to a WordPress database.

The problem arises when you collect too much data, which can bog down your servers. Imagine huge websites with thousands of members, storing all sorts of information. This could be anything from member profile data, such as names, locations, and bios, to product information for a business website. One of the challenges is the limitation of using a single database and a single server to handle all of this. What happens when your lone server fails? The whole site and it’s functionality comes tumbling down, until the server is restored to working order.

Along comes HyperDB, a plugin for spreading your site’s load across several servers and databases.


HyperDB has its advantages, which we will discuss as we continue our exploration. Why would you want to use HyperDB for your WordPress install? Here are just a few features.


Just like you might partition a hard drive on your computer, you can partition, or separate your data and spread it across multiple servers. This saves resources and helps to spread the data across multiple databases and servers. Hyper DB will try the most optimal servers first, which is helpful.

Think of it like this. If you stepped on a nail, placing your entire body weight on that single nail, it would easily go through your foot. However, if you distributed your bodyweight over an entire bed of nails, you could lay across it without being pierced. Partitioning in HyperDB is similar to the same idea. Instead of one server or database carrying a heavy load, increasing the likelihood that it will crash, it is spread across multiple servers and databases, so it is distributed evenly.


Replication is where you have multiple copies of the same server. One is a master, while the others are called slaves. You can write to the master, but you can only read from the slave servers. This may be useful for instances where security is your top priority.

It’s important to note that HyperDB does not provide replication services. You have to configure your servers that way on your own. Then, HyperDB can access them once you’ve set it up.


This is like a chain of databases and servers that act as fail safe fallback methods for each other. They all contain the same data, but if one fails, the next one will take over. If the 1st two fail, then the third one will take over. I could see this as being useful for an application that requires 100% uptime and 24/7 accessibility. If you had a site where people paid to be there, you wouldn’t want it to go down, costing you valuable revenue. You’d want to have a backup in place, ready to go if the 1st server goes down.

Failover is something you have to set up beforehand. Once that option is set up, it will query the next available server. If you don’t have it set up, HyperDB will try a few more times on its own, but it will eventually give up, returning an error.

Where HyperDB Really Gets Interesting

Big businesses could really benefit from using HyperDB to their advantage. Imagine the different types of businesses out there that rely on databases and servers to run. Think about the massive amount of storage that would be required for the servers of a nationwide, or even an international company. You aren’t limited to having your servers all in one location. You could configure them to work with remote servers in other physical locations.

A Possible Scenario

Let’s use a hosting company as an example. They don’t store football fields of servers in one location. Most bigger hosting companies have servers located at their main headquarters, but they could also have remote servers located clear across the country. Think about how useful that is, in terms of serving up data. As much as we’d like to think that data is instantaneous to any location, it would take data longer to load from a server in California if you were in New York, than if you had a server located on the East Coast.

HyperDB simply takes the limitation of one server and no configuration options for expansion, and blows the doors off. Who is stronger and will last longer: a lone body builder, or 50 nimble men of average build. Collectively, the group of men can share the work, making everything much more efficient.


HyperDB can be extremely useful for optimizing your own custom server configuration. Think of the performance you could get out of multiple servers, compared to just one. Flexibility, combined with these essential features makes HyperDB a WordPress plugin worth looking at.

If you’re looking for more information on HyperDB, check out the official docs:

Frequently Asked Questions (FAQs) about High Availability WordPress with HyperDB

What is HyperDB and how does it enhance WordPress performance?

HyperDB is an advanced database class that is designed to enhance the performance of WordPress by allowing it to interact with multiple databases. It is a replacement for the standard WPDB class and provides a range of features that are not available in the standard class. These include the ability to use multiple databases, read and write servers, dataset partitioning, and failover for database servers. By using HyperDB, you can significantly improve the performance and reliability of your WordPress site.

How does HyperDB work with multiple databases?

HyperDB works with multiple databases by distributing the load of database queries across different servers. This is known as database sharding or partitioning. It allows for the efficient use of resources and improves the performance of your WordPress site. HyperDB can also be configured to use different servers for reading and writing operations, further enhancing performance.

How can I install and configure HyperDB on my WordPress site?

Installing and configuring HyperDB on your WordPress site involves several steps. First, you need to download the HyperDB plugin and upload it to your WordPress plugins directory. Then, you need to create a db-config.php file in your WordPress root directory and configure it according to your database setup. This includes specifying the details of your databases, such as the host, user, password, and name, as well as the read and write servers.

What is the difference between HyperDB and the standard WPDB class?

The main difference between HyperDB and the standard WPDB class is that HyperDB provides advanced features for working with multiple databases. These include the ability to use multiple databases, read and write servers, dataset partitioning, and failover for database servers. The standard WPDB class does not provide these features.

Can I use HyperDB with any WordPress theme or plugin?

Yes, HyperDB is compatible with any WordPress theme or plugin. However, it is important to note that some plugins may not work correctly with multiple databases. Therefore, it is recommended to test your plugins thoroughly after installing HyperDB.

What is database failover and how does HyperDB handle it?

Database failover is a process that allows a secondary database server to take over when the primary server fails. HyperDB handles failover by automatically redirecting queries to the secondary server when the primary server is not available. This ensures that your WordPress site remains operational even if one of your database servers fails.

How does HyperDB improve the scalability of WordPress?

HyperDB improves the scalability of WordPress by allowing it to work with multiple databases. This means that as your site grows, you can add more databases to handle the increased load. In addition, HyperDB’s ability to use different servers for reading and writing operations can further enhance scalability by distributing the load across multiple servers.

Can I use HyperDB on a shared hosting environment?

While it is technically possible to use HyperDB on a shared hosting environment, it may not be practical due to the limitations of shared hosting. HyperDB is designed to work with multiple databases and servers, which may not be available in a shared hosting environment. Therefore, it is recommended to use HyperDB on a VPS or dedicated server.

How can I troubleshoot issues with HyperDB?

Troubleshooting issues with HyperDB can be done by checking the error logs and the status of your databases. You can also use the HyperDB plugin’s built-in debugging feature, which provides detailed information about the database queries.

Is HyperDB suitable for all WordPress sites?

HyperDB is particularly beneficial for large WordPress sites that receive a high volume of traffic. However, it can also be used on smaller sites to improve performance and reliability. It is important to note that using HyperDB requires a certain level of technical knowledge, particularly in terms of configuring and managing databases. Therefore, it may not be suitable for all users.