A Continuously Available, High Transaction Capacity, Soft Real-Time DBMS Server

Abstract

Large transaction processing systems, like telecommunications network service control points (SCP) ([Dou90], [WBEK91]), telecommunication operations support systems ([CMI88]), and airline ticket reservation systems ([GS84]), set very strict fault-tolerance requirements on DBMS services, particularly with respect to availability. Using a DBMS server as a platform for implementation of service control points leads to transaction service availability requirements similar to those for digital switching network elements, i.e. a maximum 1 hour of unavailability in 30 years ([Nor83]). Thus the need for what we call a continuously available fault-tolerant DBMS server. A continuously available DBMS server is termed highly available in [Kim84] and falls into the class of high-availability in [GS91]. In these types of commercial applications an unavailable DBMS server leads to serious economic problems for the operator, whether it is an airline or a telecommunications network ([Bro85]). One of the major design goals behind the HypRa DBMS server is to satisfy these system availability requirements by providing a continuously available DBMS server.