I'm curious: how easily does "easily scaled" mean? How much advance planning needs to be done about the eventual size of a cassandra cluster?
I think I can see how you can add machines when you need more capacity, but what about when you don't need all that capacity anymore? How do you go about removing machines from the cluster, and how does all of the nicely scaled out content get rebalanced when you do?
> what about when you don't need all that capacity anymore
It's not really an interesting use case... For the same reason that in every language I can think of, hashtables grow as you insert items but they don't shrink as you remove them, because if it got to size X once, it will probably do so again in the near future.
That said, decommissioning nodes will fall out naturally from our work on automatic load balancing for the 0.5 release.
Comments
I'm curious: how easily does "easily scaled" mean? How much advance planning needs to be done about the eventual size of a cassandra cluster?
I think I can see how you can add machines when you need more capacity, but what about when you don't need all that capacity anymore? How do you go about removing machines from the cluster, and how does all of the nicely scaled out content get rebalanced when you do?
> what about when you don't need all that capacity anymore
It's not really an interesting use case... For the same reason that in every language I can think of, hashtables grow as you insert items but they don't shrink as you remove them, because if it got to size X once, it will probably do so again in the near future.
That said, decommissioning nodes will fall out naturally from our work on automatic load balancing for the 0.5 release.