A Synchronisation Mechanism for Replicated Objects
by Francesc D. Munoz-Escoi, Pablo Galdamez and Jose M. Bernabeu-Auban

Abstract:

The HIDRA Concurrency Control (HCC) mechanism provides support for
concurrency control in environments where the coordinator-cohort replication
model is being used. This replication model allows the arrival of multiple
invocations to different object replicas which serve locally those
invocations and later make the appropriate checkpoints on the rest of relpicas.
The HCC uses a service serialiser object (SS) and a set of serialiser agents
placed in each replica node. As a result, since the HCC components are
replicated, this mechanism is also fault tolerant. Each invocation received
by an object replica is processed by the SS which knows the invocations that
are currently being processed. So, this agent is able to block or allow the
execution of arriving invocations according to their conflicts with the
currently active ones and the concurrency specification made when the object
interface was declared.