Object-based locking protocol for replicated objects

Distributed systems are composed of multiple objects. Each object supports more abstract operations than the low-level read and write operations. The objects are replicated to increase the performance, reliability, and availability. In this paper we discuss a synchronization method to make multiple replicas of objects mutually consistent. In the traditional optimistic two-phase locking (02PL), every replica is first locked in a read mode to write an object. Finally, all the replicas are locked in a write mode when the transaction commits. We propose a novel object-based locking (OBL) method based on the abstract operations. Here, the number of the replicas locked is decided based on the access frequency and the strength of the lock mode.