Drupal 5.x currently does not have a production-ready patch bundle to allow for split read & writes for a MySQL master/slave replication setup. After reading a open discussion/thread on the Drupal site (http://drupal.org/node/147160) and a doing a bunch of trial and error, I was successful at designing a base patch/bundle release made specifically for the Drupal 5.x environment that can do what it says along with a performance boost as well!
All of the files that are part of this release bundle are not patches, but complete code files. Follow these instructions to create your own patch bundle using the 'old' Drupal 5.x code and replacing it with the enhanced code fixes that will allow a MySQL database master/slave replication environment handle split read/write capabilities under Drupal 5.x.
- Drupal 5.x (Version 5.10 and above have better performance results)
- Existing MySQL 5.x master/slave replication environment
Sorry... this patch bundle only works under UNIX/Linux platforms.