Disaster Recovery (DR) plans address data consistency by establishing processes and technology that ensure data remains accurate, complete, and available during and after a disaster event. This often includes techniques for data backup, replication, and recovery. By carefully planning how data is handled, developers can minimize the risk of corruption or loss and ensure that systems can be restored to a consistent state that reflects all transactions up to a certain point.
One common approach to maintaining data consistency is through scheduled backups. Backups allow developers to capture the state of a database or data system at a specific time, which can then be restored in the event of data loss. Incremental backups are especially useful as they only capture changes since the last backup, significantly reducing the time and storage space needed. Additionally, backup solutions can be designed to run during off-peak hours to avoid performance issues and ensure that operational data remains consistent without disrupting user activity.
Another technique is data replication, where data is copied in real-time to another location. This can be done synchronously or asynchronously, depending on the requirements for data consistency and availability. Synchronous replication ensures that data is written to both the primary and secondary systems at the same time, maintaining consistency. However, this may impact performance. Asynchronous replication can help with performance by allowing data to be sent to the secondary site after the primary write has completed, but it does come with the risk of data loss if there’s a failure before the data is replicated. By carefully choosing between these strategies, developers can support both data consistency and system resilience in their DR plans.