Administering and Monitoring Analysis Services - SQL Server Analysis Services 2012 Cube Development - page 302

you can no longer drop the database. If you need to drop the read-only database,
you must detach it first and then manually delete its files from the data folder.
Each of the scale-out methods requires a third-party solution for balancing the query-
ing load across multiple SSAS instances. The common implementation of load bal-
ancing distributes queries using the Round-robin approach; however, this approach
could lead to one instance being heavily loaded, while others are virtually idle due
to the lightweight queries. A better approach is to check CPU and/or memory usage
on each host and send each query to the host with least resource utilization. Please
refer to the SQLCAT team blog for more information regarding query load balancing
and scaling out SSAS solutions at http://www.sqlcat.com .