Supporting Disconnected Operation in DOORS

In this paper we present a replicated object store used to support disconnected operation. The system uses an optimistic replication approach to provide high read and write availability. The development of new applications is supported by an object framework that decomposes objects in several components, each one managing a different aspect related with data sharing, such as concurrency control and adaptation to environmental changes. This way, objects can manage the “operational” aspects of data sharing in a flexible and type-specific way, using different approaches. To support disconnected operation the system also presents other features: a partial caching mechanism that relies on the definition of objects as a cluster of sub-objects; a “blind invocation” mechanism to overcome some cache misses; and integrated awareness support.