When your site is experiencing performance issues, one way to pinpoint the cause is to use profiling tools. Before you can fix the issue you have to be able to identify what's causing it. All profiling tools do roughly the same thing: they tell you what code is called during the request and how much time is spent executing it. This helps to identify the slowest code and dig deeper into the cause. Once the cause is determined you can start figuring out how to optimize the code.
For this tutorial, we’ll use New Relic as a profiling tool, but you can apply a similar methodology using the profiling tool of your choice.
In this tutorial, we'll:
- Learn how to identify and analyze slow transactions
- Look at common things to check for while profiling
- Cover some questions you should ask when looking at profiling data to help track down the slow code
By the end of this tutorial, you should know how to profile a Drupal site (specifically with New Relic) to find performance bottlenecks.
Drupal site performance relies heavily on caching. Optimal caching (and invalidation) requires that each page is rendered with the correct cacheable metadata. This metadata allows for intelligent caching -- but when something isn't working correctly, it can be tricky to figure out where exactly the metadata was generated from.
When debugging Drupal cache issues, you're usually trying to answer 1 of 2 primary questions:
- Why is this cached? If the information gets stale, why isn’t it updated?
- Why is this not cached? And why is our cache hit rate low?
The Drupal cache system consists of many layers, each of which may contribute to the problem. This tutorial focuses on debugging the Drupal application cache layer, and strategies for debugging Varnish. Given that most external to Drupal layers rely on the use of HTTP headers for caching, you should be able to use similar techniques to those used for debugging Varnish.
In this tutorial, we'll:
- Learn strategies for debugging the Drupal application cache and render cache
- Share strategies for debugging low hit rates when using Varnish
By the end of this tutorial, you should know how to enable and use various cache debugging mechanisms in Drupal to help identify problems in your site performance and resolve them.
Server scaling is the process of adding more resources (CPU, memory, disk space, etc.) to a server (or servers) to help with performance. This might be a single server, or a cluster of different machines. When we talk about server scaling, think more about the resources and less about the specific hardware. Modern servers may not always resemble a physical machine that you can open up and insert additional RAM into. But the theory is the same: more memory means the server can handle more concurrent requests.
Sometimes your Drupal site is optimized, but traffic is still high and takes most of the server’s resources. In order to sustain that load you'll need to scale your server up.
Sometimes you don’t have the resources or expertise to implement caching optimizations, refactoring code, and modifying slow queries -- all of which would improve Drupal's performance. In these cases, you may consider server scaling.
Server scaling can be done in two ways: horizontally or vertically.
In this tutorial we'll:
- Learn what server scaling is
- Discuss examples of both horizontal and vertical server scaling
- Talk about when to choose horizontal versus vertical scaling strategies
By the end of this tutorial, you should understand the concept of server scaling and how it applies to a Drupal application.
No one likes to wait for a slow site to load. Not me, not you, and definitely not search engines. And the effect of site load times on things like SEO, user bounce rates, purchase intent, and overall satisfaction are only going to become more pronounced over time.
Drupal is a modern web framework that is capable of serving millions of users. But every site is unique, and while Drupal tries hard to be fast out of the box, you'll need to develop a performance profile, caching strategy, and scaling plan that are specific to your use case in order to be truly blazing fast.
Drupal site performance depends on multiple components, from hardware setup and caching system configuration to contributed modules, front-end page weight, and CDNs. Experienced Drupal developers looking to optimize their applications know where to start looking for potential savings. They can manipulate settings and combinations of these components to achieve the desired results. Our goal with this set of tutorials is to help explain the process and provide you with the insight that comes with experience.
In this tutorial we'll:
- Introduce high-level performance concepts for Drupal that we'll then cover in more detail elsewhere
- Provide an overview of the main Drupal performance components.
By the end of this tutorial, you should understand what components around your Drupal application are responsible for site performance.
Development Environments
TopicDevelopment environments provide a sandbox where you can work on your application without affecting the live site.
Back up Your Drupal Site
TopicA reliable backup will allow you to restore your site if something goes wrong.
Comments
TopicComments are a content entity type that allows users to leave commentary associated with a specific piece of content.
Content Modeling
TopicContent modeling consists of identifying and constructing the different building blocks of data that compose the information on your site.
Content Types
TopicA content type is a subtype of the [content entity](link to Entity topic). When a content creator goes to add new content to the site, they are presented with a list of content types to choose from to get the appropriate form to fill out.
Drupal's content moderation and workflow tools allow you to configure and support a flexible multistep publication process.
An overview of some of our favorite Drupal documentation resources.
Drush
TopicDrush is a command line interface that enables you to interact with your Drupal site without clicking around the graphical user interface (GUI).
Fields and the Field API
TopicFields are the building blocks of Drupal's powerful content modeling system. The Field API allows for the development of custom field types to suit almost any data display and collection needs.
Many sites require the ability to upload, manage, and display various assets like files, images, videos, and audio.
Menus
TopicA site’s main navigation elements, whether they be in the header, footer, or sidebar, are composed of links built using Drupal's menu system. Drupal allows site administrators to build menus while also allowing module developers to add and alter menus in code.
Multilingual Sites
TopicA multilingual site has more than 1 language that users interact with, either through the content, the user interface, or both.
Search engine optimization (SEO) is the process of optimizing your online content, so that your content will rank higher in organic (non-paid) search engine results.
Views Module in Drupal
TopicLearn to use data from your Drupal site to create customized lists in various forms, such as bulleted lists, grids, calendars, or sliders.
Learn about Drupal’s configuration system and how to manage configuration with both the administrative user interface and command-line tools.