Basic issues for developing distributed applications interacting with legacy systems and databases

Legacy systems have been developed over many years. Each system was developed independently. This resulted in duplication of data and of semantics. Legacy systems and new systems communicate with other legacy systems through their user interfaces or through files. Problems that need to be addressed to include selective migration of data and functionality to corporate subject databases, maintenance of business rules, redundancy of data and distributed transaction management across heterogeneous environments. The authors´ partial solutions to these problems include: vertical slicing of applications, building procedures to support an application slice at low level of granularity, forwarding of invocation of migrated operations to existing as well as to new applications constraint enforcement at several levels, extensive use of remote procedure calls technology. Transaction processing systems will help in integrating these partial solutions. However, there is a need for comprehensive approach to solve these problems