Just tested in practice the N instances approach with Redis: what I get in similar hardware is 100k SET/GET operations per core, so using the same box dormando

Just tested in practice the N instances approach with Redis: what I get in similar hardware is 100k SET/GET operations per core, so using the same box dormando used for the test we should get 400k operations per second. Note that you'll see this numbers for both SETs and GETs, as with the single process approach of Redis there is no contention. Instead with memcached you see different numbers for SETs and GETs, I guess this is due to some kind of locking happening. It's a tradeoff, with threads you have more power against a single "object", but at the cost of more complexity and less linear scalability. Anyway it's still possible to run a memcached process per core, I would like to see this results as well. Currently I don't have access to a box with 8 different cores like the one used in the test so I can't fully replicate the test, so I hope dormando will update the results adding the test that uses four Redis instances.