Want to performance test your own WordPress installation? Try Kernl’s WordPress Load Testing service.
The database is the most important part of any WordPress site. If you aren’t adept at managing MySQL, it can be a serious risk for you and your clients. One way to de-risk this portion of your WordPress site is by going with a managed MySQL offering. There are ton of different options out there, but for this post we’re going to look at Digital Ocean’s Managed MySQL.
Why Use DigitalOcean Managed MySQL?
There are a lot of reasons to use Digital Ocean’s Managed MySQL (or some other offering) including:
- Simple Setup – With a few simple clicks you can have a high quality MySQL cluster set up.
- Horizontal Scalability – Site growing fast? You can spin up read-only nodes to help scale out read operations.
- Automated Daily Backups – No need to set up your own backups. DigitalOcean takes care of it for you.
- Automated Failover – If for some reason your primary database node fails, you will automatically fail over to your warm spare.
- Security – MySQL best practices for security are automatically followed by DigitalOcean. In addition to that your database is isolated to your private network so that outside requests can’t access it by default.
Baseline Performance Test
To get things started let’s do a baseline performance test where the MySQL database is on the same box as the Nginx server. The server configuration is as follows:
- 1GB RAM
- 3 vCPU
- Nginx
- PHP-FPM 7.2
- MariaDB 10.1
- No caching
A test of 400 concurrent users was run using Kernl’s WordPress Load Testing service. Without caching the results are predictably bad, but that is to be expected.
For completeness, let’s also take a look at the response time distribution.
Given how many failing requests we had and zero caching, the ones that did manage to get through didn’t perform too poorly. 99% in 2 seconds or less.
DigitalOcean Managed MySQL
When setting up a managed MySQL database on DigitalOcean you get the option to select the underlying hardware that powers it. For this blog post we went with the minimum possible configuration (1GB RAM, 1vCPU).
Knowing that fewer resources were allocated, it was expected that performance would actually be a bit worse on the dedicated MySQL instance. These expectations were confirmed with the load test.
All things considered, 50 req/s against a WordPress site with no caching isn’t all that bad. Once we hit that level, the database charts were showing 100% CPU saturation and thats when we started to see the error rate increase. Now let’s look at the response time distribution.
As expected performance is slightly worse here due to fewer resources on the dedicated MySQL machine, but not in a huge way.
Cost & Why Managed MySQL is Important
For our test we used the most basic configuration that DigitalOcean offers:
- 1 GB RAM
- 1 vCPU
- 10 GB Hard Disk
- No failover
- Automatic backups
All of this and not having to manage MySQL for $15/month. Not too bad, but to really be getting your money’s worth (automatic failover) you need to spend more money.
- 2 GB RAM
- 1 vCPU
- 25 GB Hard Disk
- 1 Standby node
- Automatic failover
- Automatic backups
With automatic failover you start to reduce the risk to yourself and your customers a lot. However, this level of availability isn’t free 🙂 DigitalOcean doesn’t support failover on their cheapest node, so you have to upgrade to the next level ($30/month). After that, the failover node costs you an additional $20/month. Now we’re looking at $50/month for a managed MySQL cluster with automated failover.
If you run a WordPress based business on DigitalOcean, $50/month buys you a lot of peace of mind. It’s also easy to scale up as traffic increases and the cost is competitive in the landscape of managed MySQL. If you happen to be an excellent DBA though, you can definitely manage your own cluster at a reduced monetary cost, but increased time cost.
Conclusions
Managing your own database cluster is probably fine if cost is a problem and you are good at it. In general though, if you can afford it we recommend using a managed MySQL host so you can push the complexity of operating a highly available MySQL cluster on to someone else.
Want to performance test your own WordPress installation? Try Kernl’s WordPress Load Testing service.