History merging as a mechanism for concurrency control in cooperative environments

Cooperative applications need proper transactional support for coordinating joint activities, sharing of data, and semantically correct exchange of information of collaborating users. Conventional transaction models based on the ACID properties do not meet the typical requirements of cooperative applications. The CoACT model (M. Rusinkiewicz et al., 1995) is designed for supporting cooperative work in multi user environments. CoACT includes a novel algorithm implementing the semantically correct exchange of information among concurrent activities of cooperating users by means of merging histories of user activities. This technique of merging activity histories is applicable in various fields beyond CSCW systems, e.g., in the area of mobile computing to manage disconnected operation.