RAC versus simplistic load-balancing of replicated databases

Thanks in advance for any advice about an Oracle architecture question that will help my research lab at UPenn flesh out a grant application.

For a read-only database-backed website where the data changes en masse once every couple months, the pages are pretty database-intensive, most of the application logic is in stored procedures, a small amount in dynamic pages, and the database is 2-5GB in size, ...

Q1) would scalability best be achieved by:

1. Real Application Clustering, or
2. Some sort of load balancing across multiple machines each running an independent copy of the database?

(UPenn has an Oracle site license; otherwise we would be using MySQL or PostgreSQL. )

Q2) What would be the best means of doing the replication in Q1.B above?

Q3) Regarding "some sort of load balancing", what are the options? Are there load balancers that can direct traffic based on CPU or IO loads? Or is round-robbin load balancing more practical?

Q4) In general would you run the webserver instances on the database machines, or have the webservers run on separate machines?

In either case, the load-balancing would essentially happen at the HTTP request level, since the webservers will keep database connections open. In the latter case (separate webservers), each webserver would effectively be wired to one database server, but if we put an additional load balancer in front of the database machines, that would at least allow all the webserver machines to obtain DB connections if one of the DB machines goes down. Is that correct? Some web/application servers might support software failure of DB connections also, I guess.

Q5) Are there any other questions I should be asking?

Thanks,
Kevin Murphy Received on Tue Jun 03 2003 - 14:32:25 CDT