Facebook has said that it will soon open source Prism, an internal project that supports geographically distributed Hadoop data stores, thereby removing the limits on Hadoop’s capacity to crunch data. ‘The problem is that Hadoop must confine data to one physical data center location. Although Hadoop is a batch processing system, it’s tightly coupled, and it will not tolerate more than a few milliseconds delay among servers in a Hadoop cluster. With Prism, a logical abstraction layer is added so that a Hadoop cluster can run across multiple data centers, effectively removing limits on capacity.’