Reconciling Replication and Transactions for the End-to-End Reliability of CORBA Applications Pascal Felber and Priya Narasimhan   View Paper (PDF)   Return to Dependability, Security, Assurance Abstract The CORBA standard now incorporates support for reliability through two distinct mechanisms - replication (using the Fault Tolerant CORBA standard) and transactions (using the CORBA Object Transaction Service). Transactions represent a roll-back reliability mechanism, and handle a fault by reverting to the last committed state, and by discarding operations that were in progress at the time of the fault. Replication represents a roll-forward reliability mechanism, and handles a fault by re-playing any operations that were in progress at another operational replica of the crashed server. Most of today's enterprise applications have a three-tier structure, with simple clients in the first tier, servers in the middle-tier to perform the processing, and databases in the third tier to store information. For such applications, replication is required to protect the middle-tier processing, while transactions are required to protect the third-tier data. This requires the reconciliation of roll-forward and roll-back reliability mechanisms in order to protect both data and processing, and to provide consistent end-to-end reliable operation. This paper looks at the issues of integrating replication with transactions for three-tier enterprise CORBA applications, with particular emphasis on reconciling the Fault Tolerant CORBA standard and the CORBA Object Transaction Service. DiSC'03 © 2003 Association for Computing Machinery