CLOB: Communication Support for Efficient Replicated Database Recovery

Abstract

Replication protocols using an eager update propagation strategy commonly need a reliable broadcast service; i.e., a broadcast primitive with atomic delivery and, in some cases, also with total order. This communication service provides some appropriate features for the recovery tasks, although in some cases this leads to partial blocking of the replica taken as the source in the updating process. CLOB is a framework for reliable broadcast protocols that log the missed update messages in case of failure, being able to automatically resend these updates when the faulty destinations recover. This behaviour is easily configurable and allows an efficient recovery mechanism in case of short-term failures, which can be combined with other version-based recovery protocols in order to manage long-term outages.