Database development supporting offline update using CRDT: (Conflict-free replicated data types)

Database is nowadays a crucial data storage for application needs. Currently, there are several existing popular databases such as relational database like SQL and non-relational database (i.e. NoSQL). However, both types have their own drawbacks which could not be utilized in both online and offline modes concurrently. Therefore, the authors develop a database that supports both modes especially availability in offline mode without sacrificing consistency. The database is integrated with CRDT (conflict-free replicated data types) algorithm to handle and solve conflicts in synchronization process. Some tools and technologies are used in the database development including Apache Thrift for middleware, LevelDB for server database, and IndexedDB for temporary client database. The purpose of this development is to build a CRDT database with usable API for developer users. Finally, it is tested with scenarios to satisfy essential operations: add, remove, and update.