DatabaseMirror
DatabaseMirror is a high-availability solution for Microsoft SQL Server databases. It provides a near real-time copy of a production database on a separate server, ensuring data redundancy and minimizing downtime in case of hardware or software failures. The primary server, known as the principal, is the active database that handles all read and write operations. The secondary server, known as the mirror, is a passive copy that receives transaction logs from the principal and applies them to its own database. In the event of a failure on the principal server, the mirror can be promoted to become the new principal, allowing for quick recovery and minimal data loss.
DatabaseMirror operates in one of three modes: high safety, high performance, or high availability. High safety
DatabaseMirror is a synchronous replication technology, meaning that the mirror server must acknowledge receipt and application
DatabaseMirror was introduced in SQL Server 2005 and has been deprecated in SQL Server 2012, with AlwaysOn