Having looked at it a little more, a true shared nothing architecture through all layers of the stack probably isn't achievable. Moodle doesn't currently support the concept of database sharding etc. It's largely oriented towards a single database. Maybe its possible at the layers above; certainly if you push sessions back to the database then you can scale out your web server cluster.
Hardware and performance
Could Moodle support a shared nothing architecture?
This discussion has been locked because a year has elapsed since the last post. Please start a new discussion topic.