As Personalized Web Environment (PWE) and SNS is growing, NHN has developed a social networking service called NAVER.me which pulls user's data, including event alarms, messages from emails, comments made on any blog or at any social service linked to naver.com, and displays everything at one place in a user friendly way. This personalized service operates enormous data, thus requires scalability and high-availability. At the same time it is necessary to keep support for legacy codes in linked applications, and provide the compatible interface for backend processing system which uses RDBMS. For this purpose, NHN has developed a new distributed storage system called nStore, which takes advantage of both RDBMS and NoSQL. As a result, nStore has the following characteristics:
During the load balancing process, the data is distributed by a unit called the Container group.
Faster than a traditional RDBMS, but slower than pure memory caching systems like Arcus.
Provides unlimited capacity to serve as a permanent storage space.
As nStore uses RDBMS as a base storage engine, it supports SQL like query language (nSQL).