I presented on the Drupal CMS Multi-Site at CMS Expo in Chicago, and I wanted to share some of what I spoke about in the blog.
Why Use Multi-Site?
Multi-site technology has been around for a few years now. A multi-site is when one code base manages multiple websites. We were doing multilingual shopping carts back in 2004, where one code base ran a number of different language versions. Multi-site can offer big savings if your company has websites that share functionality, users or products.
Multi-Site Cost Savings
Some benefits of multi-site are being able to search and share member profiles across all of the sites; maintaining an independent mobile version of your site; and having a single shopping cart for all of your sites. But the biggest advantages are being able to maintain one code set, sharing themes and modules. This can produce a significant savings of up to 70% in development costs and 40% to 50% in operating costs through code reuse.
E-Commerce and Multi-Sites
You can use the same profile for all of your sites - helping to improve cross-promotion, loyalty, and conversions. This dovetails well into a unified e-commerce strategy where all purchases can be tracked in a member's profile, accessible through any multi-site or mobile device. This also facilitates a simplified real-time inventory since you only need a single e-commerce engine and financial reconciliation is much easier.
Multi-Site vs. Multilingual Module
Multi-site is also an easy way to have multilingual versions of your Drupal website, since the Multi-lingual module can be limiting and has issues when working with customized content permissions. Tie in your mobile versions and you can see how the costs savings can add up.
Three Approaches to Drupal Multi-Site
There are three approaches to building multi-sites in Drupal, and each has its pluses and minuses: Drupal Multi-site, Aegir and Domain Access.
- Drupal Multi-site (the core functionality) shares at least core and can share Database, Themes, Users or modules. It can not share content and it is challenging to update differing functionality.
- Aegir deploys a common install profile and is tremendous in managing a large number of sites where the functionality is similar. It cannot share content though and is still in beta.
- Domain Access deploys sites on different domains and is great at sharing content. Its downside is all functionality has to be the same on the different sites. The decision to share databases is a trade-off - easily sharing content and users verses performance and scalability.
Things to look out for
Be careful however, because there are some things to watch out for when evaluating whether or not to use a Multi-site architecture.
First, not all circumstances warrant building a multi-site. If you can accomplish your goals with a single site, then this will be the most cost-effective solution. If your sites are not that similar, multi-site may be too expensive and restrictive. When you update a multi-site stack, you have to update all of the sites. Also, not all modules are multi-site friendly. The Locations module, for example, organizes data in ways that are not friendly to a multi-site architecture.
Multi-site has huge benefits for our clients, such as the Kabbalah Centre, and to companies such as Sony Records or Warner Brothers, who have a large number of artist sites that share users, functionality and e-commerce. Since multi-site is a complex approach with different alternatives itŒÍs best to have a firm like CommonPlaces guide you through the implementation with planning, architecture consulting, and development mentoring.