WordPress now has a global market share of over 65 percent among content management systems (CMS). Despite this, WordPress is still sometimes ridiculed as a small CMS. But WordPress has nothing to hide - especially when it comes to high performance. Today we'll show you what WordPress can do here.

How your magazine survives 75,000 views per minute

Difference between calls and visits

Before I reveal the secret of how your website can handle an extremely high number of visits, I would first like to explain the relationship between visits and views. A person can of course visit several subpages. The reflection time between clicks is the key figure for establishing a relationship between visits and views.

If 900 people click on a website every three seconds on average, we have 300 hits per second for 900 visits.

As an important rule of thumb, the number of visits is generally at least twice as high as the number of views.

WordPress & high performance - caching as a miracle weapon

So how does a website manage to handle up to 150,000 visits per minute without falling to its knees? The miracle weapon that we use at Raidboxes, even at the lowest rate, is called caching.

Our caching is not a separate Varnish server that is laboriously connected upstream, but a technology that is integrated on the server side as standard.

The cache transfers a mixture of stylesheets, JavaScript, images etc. into a static HTML document, stores it temporarily and delivers it when the page is called up. The static documents are stored in the working memory or on the SSD hard disk.

Thousands of calls and the processor gets bored

Thanks to server-side caching, the requests are delivered directly without even making contact with the processor and the database. In our starter tariff, for example, 75,000 requests can be answered within one minute as standard. WordPress is therefore an excellent system, especially for visitor-intensive websites such as blogs, magazines and those of larger companies.

We have often experienced this in high performance times, for example after the mention of certain websites in a TV program or during online marketing campaigns: Although the server was upgraded in advance, the processor load usually remained at a low level because the caching had largely taken over the delivery of the pages.

High performance special case - WooCommerce

However, there is one important restriction: The statement refers to static pages that can be stored in the cache.

Dynamic requests can be poorly cached

Dynamic requests, such as filling out contact forms or checkout processes in the shopping cart, must not be cached.

One example of dynamic content is product pages where the prices in the shopping cart change depending on the interaction with the website. It would be fatal here if the price in the shopping cart or even at the checkout did not adjust and the cached price was permanently displayed.

Such dynamic pages are therefore excluded from our caching by default in order to ensure flawless operation. Simultaneous visits to websites with a shopping cart therefore usually have a direct impact on the processor.

In the same way, communities and membership websites with forums and many people logged in are difficult to cache. There is a serious need for action here in terms of hardware resources.

The chip shop as a meaningful metaphor

Without caching, only a higher number of CPU cores can help, which can then answer a high number of simultaneous visitor requests. There is the chip shop as a metaphor to explain the principle:

Each CPU core represents one person behind the counter of the chip shop. The more people frying at the same time (cores available), the more fries can be sold (requests can be answered).

Incidentally, this does not apply to the speed at which people work. For this, the CPU clock frequency would have to be increased. This is the case with our tariffs from the PRO tariff upwards, where the processors are up to 30 percent faster.

Approximately 600 simultaneous visits to the shopping cart as a maximum

With two days' notice, we can manually upgrade tariffs to 36 cores and 64 GB RAM for 24 hours. This is particularly popular with many start-ups that will be appearing on TV shows such as "Die Höhle der Löwen" and want to play it safe during the expected peak load.

For the large WooCommerce store, there is then our largest high-performance tariff "Business XXL" with 12 vCores and 32GB RAM. Here you can have up to 600,000 cached visits per minute or up to 600 visits per second in the shopping cart.

Load balancing as the next step

In the event that even more visits per second need to be processed, load balancing is the next step. A load balancer is placed in front of the actual servers to distribute the requests to the servers. Load balancing is therefore about distributing the load.

This allows scaling across hardware resources not only on the same server, but also across server boundaries. This is a procedure that has been established for decades and is ideally suited to directing high traffic into sensible channels without downtime.

Load balancing can be realized, for example, through a so-called Content Delivery Network (CDN). With a CDN, the servers are distributed worldwide and enable fast access to the website from almost any country. Each of these servers stores a cached version of your website and delivers it to the end device. A CDN is particularly worthwhile when it comes to an international website, as not only the server load but also the latency time plays a role here. Providers such as Cloudflare offer the option of a CDN.

Conclusion: WordPress & high performance have long been a very good match

Anyone who still classifies WordPress as a CMS for small websites should urgently reconsider this. WordPress has long since established itself as a CMS for high-performance websites and is used here in a variety of ways. Caching in particular is helping WordPress to reach new heights.

Even large online stores with constantly high traffic can be handled reliably with the right hosting. In countries like the USA, this is no longer a secret. I hope I was able to show you in this article that we in Germany can also trust our favorite CMS to do more.

How have you seen WordPress so far? Have you perhaps already built high-traffic websites? I look forward to your comments!