> Another thought would be at the application layer, sending
> all the updates (insert,delete, update, etc) to server A,
> and the selects to the local slave servers.
This has been suggested before, and I'm totally against it. Applications like PHPBB,
Drupal, WordPress, etc can't be easily configured to do this, and I'd really like to use
those applications in a more robust and redundant environment.
Pushing the work of this sort of master/slave relationship to the application level means
that most applications will not support it. Replication is a database server problem,
not an application problem.
Baskin School of Engineering
UC Santa Cruz