It is difficult enough to find data in a large database, but imagine if you also needed to locate the data and map its location in relation to other pieces of data. A distributed memory system needs to be able to place data on a specific node and also do so without putting an enormous amount of stress on the nodes in a cluster. Rather than randomly allocating data using consistent hashing , this type of distributed RAM grid would need to use locality-sensitive distribution.
Enter SpaceBase, a real-time spacial data store for massive multiplayer online (MMO) games, location-based services, and military C4I systems. Created by an Israeli technology company called Parallel Universe, SpaceBase is capable of distributing data in the cluster nodes’ RAM, rather than on disk, essentially creating an in-memory data grid (IMDG). The result is a low latency data system that is consistent and can meet the demands of a power-hungry application.
The next problem that presented itself was the moving object. As an object moved throughout the virtual universe (or real one, as the case may be), a distributed hash table (DHT) would have to change hash values every time the object moved, slowing down the system and defeating the purpose of locality-sensitive data. Instead, the company created Galaxy, an IMDG that relies on cache-coherence protocol, which is similar to the caching system found in CPU L1 caches. Whenever an object changes location in space, the database would request Galaxy to move its data to another node located closer to other data from actual nearby objects.
Parallel Universe has released Galaxy to the public under an open source LGPL license. It is still considered experimental and filled with bugs, but the company has released it in order to further research in the area. For the unique industries that can make use of it, including MMO gaming, it will be a welcome addition to database management and could change the way companies optimize and store their data.