A fault-tolerant object service on CORBA

The Common Object Request Broker Architecture (CORBA), is a major industria l standard for distributed object-based applications. Today's large-scale C ORBA applications have to deal with object crashes, node failures, networks partitioning and unpredictable communication delays. Existing efforts to e nhance the CORBA reliability can be roughly categorized into three approach es: integration approach, interception approach and service approach. Each approach has its own merits and prices. In this paper, we propose a service approach solution called Object Fault-tolerance Service (OFS). Solutions t hat adopt the service approach usually specify their service in terms of CO RBA IDL interfaces. The implementations of such solutions in general do not modify the ORE infrastructure or IDL language mappings, and thus applicati ons developed with those systems appear to be more portable. OFS differs fr om other service approach solutions in that OFS does not assume underlying support of reliable group communication. Applications with advance registra tion can rely on OFS for detection of object and node crashes, and for cust omized recovery. In this paper, we first present the service specification of OFS. We then give the system architecture of an OFS implementation. This OFS implementation is developed on the Solaris 2.5 platform and with IONA' s Orbix 2.0. The performance evaluation of the OFS implementation is also p resented. The preliminary experiments indicate that OFS overhead is minimal and client objects experience little response delay when a service object is under OFS surveillance. (C) 1999 Elsevier Science Inc. All rights reserv ed.