title: Can I use Terracotta to scale a RAM-intensive application?
body: <p>I'm evaluating Terracotta to help me scale up an application which is currently RAM-bounded. It is a collaborative filter and stores about 2 kilobytes of data per-user. I want to use Amazon's EC2, which means I'm limited to 14GB of RAM, which gives me an effective per-server upper-bound of around 7 million users. I need to be able to scale beyond this.</p>
  
  <p>Based on my reading so-far I gather that Terracotta can have a clustered heap larger than the available RAM on each server. Would it be viable to have an effective clustered heap of 30GB or more, where each of the servers only supports 14GB?</p>
  
  <p>The per-user data (the bulk of which are arrays of floats) changes very frequently, potentially hundreds of thousands of times per minute. It isn't necessary for every single one of these changes to be synchronized to other nodes in the cluster the moment they occur. Is it possible to only synchronize some object fields periodically? </p>