Thank you for your answer. The problems I see with (a) from the top of my head are:
1. Even if it's easy, somebody has to do that.
2. Setting up all the monitoring etc for each instance
3. Running more than one riak daemon on the same machine means that the riak daemon is unaware of the IO operations performed by the other one, hence IO throughput could suffer. This means that in practice you would need to mount separate disk heads (and we are back to 1.)
4. Each riak instance will require some RAM as well, so memory has to be allocated and there is the risk that's over-allocated.
5. Port allocation. I fear it would end up with smth like: "just keep a internal wiki page where each 'db space' is mapped to a port number"
Well, the problem with (b) is of course that I don't have time to do that. For now we stick to cassandra, but Riak is so nice in many aspects that I really hope that at some point, as the product matures, more resources can be invested in aspects which are not currently perceived as "selling points" for riak, but are important for some scenarios and not technically impossible.
Yeah, if you're using Cassandra and the GC/rebalancing issues aren't affecting you, you're probably fine sticking with it. Both are Dynamo-structured, so your consistency/failover model advantages are similar.
1. Even if it's easy, somebody has to do that. 2. Setting up all the monitoring etc for each instance 3. Running more than one riak daemon on the same machine means that the riak daemon is unaware of the IO operations performed by the other one, hence IO throughput could suffer. This means that in practice you would need to mount separate disk heads (and we are back to 1.) 4. Each riak instance will require some RAM as well, so memory has to be allocated and there is the risk that's over-allocated. 5. Port allocation. I fear it would end up with smth like: "just keep a internal wiki page where each 'db space' is mapped to a port number"
Well, the problem with (b) is of course that I don't have time to do that. For now we stick to cassandra, but Riak is so nice in many aspects that I really hope that at some point, as the product matures, more resources can be invested in aspects which are not currently perceived as "selling points" for riak, but are important for some scenarios and not technically impossible.