Middle-R for scalable database replication A recently developed middleware infrastructure provides support to adaptive web services that can be composed even across organisational boundaries. Digital Economy © PhotoDisc The ever-increasing use of the web for information delivery or purchase of goods has led to new business challenges. Organisations are able to provide value-added, inter-organisational services through composition of multiple basic services into composite ones. Key prerequisites for this are the availability, scalability and adaptability of the services to ensure prompt processing of user interactions even under highly dynamic scenarios. Urged by this the ADAPT project aimed at advancing middleware technologies to compose adaptive and composable web services. One of the project results is the Middle-R, a middleware for database replication. Database replication offers increased throughput while at the same time it may considerably reduce response times. Hence, organisations can handle more requests with efficient load balancing. Middle-R allows database replication in a scalable fashion even with workloads of significant ratio of updates. It offers full consistency by implementing synchronous replication. It can work on top of any database providing snapshot isolation. One of its most distinguishing features is its increased potentialities for advancing the scalability of database replication. It comes in two versions, one in C and another in Java. Collaboration is sought with industrial partners for commercialisation of the product. The prototype is offered for free use under a BSD-like license. For further information, click at: http://adapt.ls.fi.upm.es/adapt.
