Scaling WordPress MU with multiple databases

Our larger WordPress MU install, Homeschool Journal has been running on multiple databases for about 3 years. Technically, it’s possible to have thousands of blogs in a single database install. Usually where people running MU start to have issues with the number of blogs is with getting complete backups of the database.
Upgrades with multiple databases have always been more work and many people running multiple databases typically did not upgrade until the .1 release of whatever version of MU. When I upgraded Homeschool Journal to MU 2.7.1, it was two weeks before I had found and repaired all of the database issues (via several plugins). I decided I wasn’t going to go through that again.
With the number of blogs at WordPress.com, Automattic must be using a database plugin that supports WordPress MU better. So, over a couple of weekends, I tweaked HyperDB to use the same MD5 hash…

You Might Also Like...

  • SharDB update

    5962 readersI updated SharDB (Download) for WordPress MU 2.9.1.1 and added support for the comment meta table. December 29, 2009 — Scaling WordPress MU with multiple databases (31) September 24, 2009 — Changing the domain (17) January 21, 2010 — Testers, start your engines (6) January 14, 2010 — 2.9.1 released, last before merge (6) January 6, 2010 — Merge News

  • Bulk Import Users

    2697 readersI had a few requests to update the Bulk Import Members plugin, so that it did not require BuddyPress to be installed and that it work with WordPress MU 2.8.6. Other changes: it now goes in the plugins folder & activates sitewide. The only users who have access to the plugin are site admins. it

  • WPMU Default User Role

    2000 readersDeanna & Kevin released the WPMU Default User Role plugin earlier this week. In WordPress MU, new users are added to the site’s dashboard blog if the site admin has created one. Otherwise the user is added to the main blog in the WPMU site. With the default user role plugin, you can specify additional blogs

  • WordPress Backup Plugin by Blog Traffic Exchange

    302 readersAbout a year and a half ago we wrote about how to backup your WordPress blog.   In that post, we covered a few different WordPress plugins to manage your database backups, and explained why that was so important.   For the record, the plugin I primarily recommended back then and still prefer today is the

  • ;)

    The age of Thelonious and WordPress 3.0

    2884 readersThe penny has dropped, the vuvuzelas have sounded and the kitties have played themselves out. WordPress 3.0 has been officially released. Check out the official release post from Matt. I’ve been watching the download counter whirl by. This release marks the official end of separate WordPressMU development. The exisiting functionality is now a part of

  • ;)

    Upgrading from WPMU to WP 3.0

    1452 readersNow that 3.0 is officially released, you may have seen an upgrade notice in the backend of your WPMU install. While the process is generally just clicking the upgrade button, there are a couple of additional steps to fully smooth out any merged changes that occurred. First, backup your database(s) and the entire wp-content folder.

  • Sitewide Tags 0.4

    1280 readersAndrea & I use Donncha’s Sitewide Tags Blog for global content aggregation on any client installs that use sitewide content. Over the last year I’ve made at least a dozen custom versions of it. Most of those do some combination of the features listed below. This week we tested and released a new version. The

  • wpdbmanageruninstall

    Cleaning Up A WordPress Database After Plugins and Themes Are Uninstalled

    488 readersI have been thinking about this post for a while.  It really started to come to me after I went through a server move of my own website which I discussed on this site last month – Moving Your WordPress Site and Database. I did a lot of manual cleaning of my database to get

  • Browse database tables in PHPMyAdmin

    6 things to remember when moving WordPress blogs to a different host

    406 readersI recently had to move all my WordPress sites and blogs to a new server because Bluehost sucks. My sites were going down on a near-daily basis for way too long, and they couldn’t care less. So I did what I really did not want to do, and moved six WordPress sites to a new

  • Should you use WPMU?

    2893 readersWith news of the merge of the Wordpress & WordPressMU codebase becoming more widespread, one of the questions I get asked with increasing frequency is should someone start a new site based on MU or should they wait for the merge. My answer? It depends. Is it time-critical? Do you need it up and running sooner rather