The document describes a middleware for implementing highly available distributed databases called HDDBRS. It has the following key points: 1. HDDBRS uses a 3-tier architecture with clients, middleware, and backend database servers. The middleware handles redundancy, recovery, and failure detection in a transparent way. 2. The middleware uses erasure coding techniques to stripe and encode data across multiple database servers for redundancy while minimizing storage overhead. It can recover lost data or servers. 3. A demonstration showed it could recover a failed server with 6% overhead, and recover a 3KB record in 130ms with 0.18ms for decoding. The middleware provides high availability, scalability, and performance.