One of my clients is proposing a project that requires good storage performance and high reliability. It's an entirely new project so there's no legacy code to deal with. The traditional way of doing this would be to have a cluster of systems maybe in an activa/passive configuration with database replication or with MySQL or PostgreSQL clustering. Those solutions are difficult to manage and upgrade. http://en.wikipedia.org/wiki/Apache_Cassandra I think that probably the best thing to do is to use something like Cassandra on a cluster of servers in a DC to run this. The Cassandra feature set seems good (including being able to add new servers at run-time) and developing it from scratch can't be a lot harder than doing MySQL development. Does anyone have any suggestions for planning at this early stage? I had thought of doing something similar with the Amazon EC2 equivalent to Cassandra, but a quick scan of their web site reveals no mention of it. Did Amazon cancel their cloud key-value store service? -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/