Description:
This patch modifies Drupal core so it can be configured to send specified queries to a one or more MySQL replication slaves, helping to distribute the database load. This patch alone does not change where any queries are run.

An optional 'replication-slave.patch' utilizes the changes made in the first patch. It causes all temporary tables to be created on the slaves, sends all pager queries to the slaves, and sends some queries from node_load to the slaves.

Until recently, I was a student employee at the Oregon State University Open Source Lab. My career there ended, like many, with that painful process known as graduation. I got invaluable experience at the lab, not the least of which being the knowledge gained as their main (only) database administrator. One of my great pleasures in that position, was learning how to configure MySQL replication and manage clusters of replicating database servers. Even the simple case of a single master and a single slave has its edge cases.