ARCUS is an open-source in-memory Cache Cluster based on memcached. ARCUS supports collection data structure (List, Set, Map, B+tree) for storing/retrieving multiple values as a structured form in addition to the basic Key-Value data model of Memcached. It was implemented as an elastic cache cluster by using ZooKeeper to provide horizontal scale-out, where nodes can be added/removed on the fly, and with a fault-tolerance feature, it detects failed nodes and automatically removes them. ARCUS provides remote caching services to multiple applications while reducing the load to a database by caching and servicing hot-spot data.

ARCUS Single Cache (Dev.) consists of a single node and supports one-click deployment to experience the basic features of the ARCUS Cache Cluster. The current configuration of ARCUS Single Cache (Dev.) supports only 250MB memory and 1024 client connections.