MySQL cluster for Drupal?

We have a pretty busy site based on Drupal and I was thinking of introducing some form of clustering for HA and Load balancing.

However, http://drupal.org/requirements says: Drupal supports MyISAM and InnoDB table types. NDB tables (MySQL Cluster) are not supported.

Does that mean I can't use a MySQL cluster to run Drupal? Or did I get that wrong?

Also, how many servers(virtual or physical) would we need to guarantee redundancy for a Drupal site? What software should I be using? I have googled for days and apparently there are many options available so a bit confused here..

Solution 1:

This is the use case for MySQL Cluster.

Check out Percona XtraDB Cluster (based on Galera) for a similar (i.e. synchronous) solution for use with web applications. Note that it is an alpha release but it is probably the most promising solution out there today. Schooner also has a synchronous solution. There is also Continuent's Tungsten although it is an asynchronous solution.

Hope this helps.

Cheers