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Optimising a Drupal CMS

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Optimising a Drupal CMS

Drupal is a powerful and flexible CMS, ideal for complex projects. However, to achieve top performance, every aspect must be carefully considered – from infrastructure to code optimisation. A well-optimised Drupal site not only loads faster but also provides a better user experience and more efficient use of server resources.

 

1. Hosting and Infrastructure

Everything starts with the server. Choosing the right hosting solution is the foundation for building a high-performing Drupal site. It’s best to go with a VPS or dedicated hosting, avoiding shared solutions that can slow down execution. Using PHP-FPM, a well-tuned database (such as MariaDB or MySQL), and server-level caching systems (such as OPcache or Varnish) can make a significant difference.

Key practices:

  • Use dedicated hosting or VPS instead of shared hosting.
  • Run optimised PHP-FPM and MariaDB/MySQL.
  • Enable OPcache and HTTP/2.
  • Integrate a CDN (Cloudflare, Fastly…) for static assets.

 

2. Caching

Drupal’s caching system is sophisticated and can be configured on multiple levels. For anonymous users, Page Cache is essential. For authenticated users, Dynamic Page Cache comes into play. In more advanced environments, you can integrate external caching tools such as Redis or Memcached, and use Varnish as a reverse proxy to serve pages extremely quickly.

Don’t forget to configure caching for Views, blocks, and even Twig templates, which can benefit from proper cache metadata strategies to avoid unnecessary rendering.

Best practices:

  • Page Cache for anonymous users.
  • Dynamic Page Cache for authenticated users.
  • Internal cache or external systems such as Redis and Memcached.
  • Varnish as a reverse proxy for ultra-fast delivery.
  • Configure cache for Views, blocks, and Twig templates.

 

3. Code and Template Optimisation

Another critical area is how you write your code. Twig templates should be kept as “light” as possible, with complex logic delegated to preprocess functions or controllers. It’s also important to aggregate and minify CSS and JS files to reduce HTTP requests – using either Drupal’s built-in tools or advanced modules such as AdvAgg. In general, less code means faster execution.

Recommendations:

  • Avoid complex logic inside “.twig” templates.
  • Use cacheable metadata functions to make pages more cache-friendly.
  • Aggregate and minify CSS/JS (core aggregator or modules such as AdvAgg).
  • Avoid unnecessary queries in hooks or preprocess functions.

 

4. Module Management

In Drupal, each enabled module adds code and potentially extra database queries. It’s essential to uninstall unused modules and carefully evaluate any new additions. Some modules, such as Views UI, are useful during development but not needed in production. Tools such as Devel and Webprofiler help you identify slow parts of the site and visualise heavy queries and bottlenecks.

Tips:

  • Uninstall unused modules (every active module adds overhead).
  • Avoid heavy modules unless absolutely necessary (e.g. disable Views UI in production).
  • Use modules such as Devel and Webprofiler to analyse performance.

 

5. Monitoring and Profiling

A fast site is also a monitored site. Profiling tools such as XHProf, Blackfire, or New Relic allow you to measure the exact response time of your code and database interactions. In addition, system logs and Watchdog messages are essential for spotting errors or warnings that could slow down execution.

Tools to consider:

  • XHProf, Blackfire, New Relic for profiling and identifying bottlenecks.
  • Watchdog, syslog, Apache/Nginx logs to catch errors and warnings.

 

6. Cron and Task Queue

Many of Drupal’s background tasks are handled via cron, but relying on user-triggered cron execution is not ideal. It’s better to use an external cron system that pings Drupal at regular intervals. For heavier tasks – such as sending bulk emails or processing large datasets – it’s advisable to use the Queue API, which helps distribute the load efficiently.

Suggestions:

  • Use an external cron system (not Drupal’s internal one) for better responsiveness.
  • Use the Queue API or modules such as Queue UI and Advanced Queue for heavy tasks.

 

7. Security and Updates

A slow site is often also an insecure one. Keeping the core and modules up to date is vital not only to avoid vulnerabilities but also to benefit from performance improvements introduced in newer versions. Additionally, enforcing HTTPS, using security headers, and restricting access to the admin area are best practices that should not be ignored.

 

Conclusion

Optimising a Drupal site requires attention and skill, but it’s a worthwhile investment that pays off in terms of speed, reliability, and user satisfaction. There’s no single magic trick or module – what you need is a holistic approach that sees infrastructure, caching, code, modules, and security as interconnected pieces of a single ecosystem that must work together at their best.