Adding a new site in an existing Oracle Multimaster replication without quiescing the replication

TL;DR

This paper introduces a novel method for adding a new site to an Oracle Multimaster replication system with minimal downtime by implementing an intermediate layer that modifies DML statements during site addition.

Contribution

It proposes a new layer that temporarily intercepts DML statements, enabling online addition of a new replication site without system downtime.

Findings

Reduces system downtime during site addition

Effectively intercepts and modifies DML statements

Compatible with existing Oracle Multimaster setups

Abstract

This paper presents a new solution, which adds a new database server on an existing Oracle Multimaster Data replication system with Online Instantiation method. During this time the system is down, because we cannot execute DML statements on replication objects but we can only make queries. The time for adding the new database server depends on the number of objects, on the replication group and on the network conditions. We propose to add a new layer between replication objects and the database sessions, which contain DML statements. The layer eliminates the system down time exploiting our developed packages. The packages will be active only during the addition of a new site process and will modify all DML statements and queries based on replication objects.