Couchbase Server 2.5 introduces advanced features for enhancing high availability and disaster recovery, crucial for maintaining mission-critical applications with minimal downtime. Notable among these is "Rack Awareness," which ensures that replica data partitions are stored on different physical racks from their primary counterparts, allowing the system to remain operational even if an entire rack fails. Additionally, Couchbase supports cross datacenter replication, enabling active-active data replication across geographically dispersed datacenters, a vital feature for disaster recovery. These capabilities, along with enhanced security and connection management, make Couchbase Server 2.5 a robust solution for enterprises aiming to safeguard their applications against various forms of system failures.