Monimasterijärjestelmät

Monimasterijärjestelmät, known in English as Multi-master systems, refer to a type of distributed database architecture where multiple nodes can accept write operations simultaneously. Unlike traditional master-slave configurations where only one master node handles writes, in a multi-master setup, any node can be designated as a master, allowing for distributed data management and increased availability. This architecture is particularly beneficial for applications requiring high write throughput and low latency access across geographically dispersed locations.

The primary challenge in multi-master systems is managing data consistency. When multiple nodes can modify data concurrently, conflicts can arise if the same data item is updated on different masters before those updates can be synchronized. Various conflict resolution strategies are employed to address this, such as last-writer-wins (LWW), version vectors, or application-specific merging logic. The choice of conflict resolution significantly impacts the system's behavior and the accuracy of the data.

Multi-master systems offer several advantages, including improved fault tolerance and scalability. If one master node fails, other masters can continue to process requests, ensuring high availability. Furthermore, by distributing write operations across multiple nodes, the system can handle a larger volume of transactions than a single-master setup. However, these benefits come at the cost of increased complexity in terms of synchronization, conflict resolution, and overall system management. Examples of databases that support multi-master configurations include certain versions of PostgreSQL with extensions, CockroachDB, and NuoDB.