Membase

Membase was an open-source distributed key-value store designed to provide scalable, durable storage by combining in-memory caching with persistent storage on disks. It was built to run on commodity hardware as a cluster and to serve web-scale applications that require low-latency data access and high availability. Data in Membase was stored as key-value pairs and could be accessed through a memcached-compatible protocol, while the system also persisted data to disk to preserve data across restarts and failures. The architecture supported automatic data partitioning across nodes, in-memory caching of hot data, and replication for fault tolerance. It also offered features such as node replacement, dynamic rebalancing, and cross-datacenter replication in some configurations.

Membase originated in the late 2000s as an effort to add persistence and replication to memcached. It was developed by NorthScale and the open-source community and later formed an alliance with CouchOne. In 2011, Membase merged with CouchOne to form Couchbase, Inc., and the Membase project was folded into the Couchbase Server product line. Since then, the technology that began as Membase has continued within Couchbase Server, which provides a similar memory-first architecture with integrated caching, persistence, and cross-datacenter replication.

Today, Membase as a standalone project is no longer maintained. Its concepts—memory-first caching, disk-backed persistence, sharded data, and multi-node replication—live on in Couchbase Server and inform ongoing work in distributed, document-oriented databases.