Eventing in Information Systems Based on Command Query Responsibility Segregation Design Pattern

Information systems based on Command Query Responsibility Segregation utilize the separation of read and write operations to the database. This separation enables the use of multiple databases and their configurations to further separate read and write operations. In the case of multiple databases, it is essential to implement synchronization between databases. Regardless of the chosen database configuration, the bottleneck remains. Bottleneck are write operations to the database. To minimize the impact of the bottleneck, developers must choose the appropriate solution. A strong consistency database model guarantees that all changes will immediately be written in the database. Another database consistency model is eventual consistency, which guarantees that all changes will eventually be written in the database with a delay. This delay in the information systems can result in inconsistent information in the user interface if more users simultaneously work with the same data. This paper aims to describe the use of strong and eventual consistency in the database for write operations in the information system based on Command Query Responsibility Segregation. The presented solution enables the use of two database consistency models for write operations and improves system performance. This paper presents a practical application of the described database consistency models.