Use of a CORBA/RMI gateway: characterization of communication overhead

Many distributed applications make use of distributed object technology. In this kind of systems, modules providing services are implemented as objects spread over a network. Distributed objects are usually accessed through communication frameworks based on specific middleware solutions, such as CORBA, DCOM, and RMI. Applications of this kind might be built up (or extended) integrating different modules, possibly already coded and available on the market. Each required and available module might use a specific communication framework, hampering its prompt integration into a system exploiting a different framework. A convenient way to tackle this problem is the insertion of a gateway module, passing service requests between two different middleware solutions. This approach allows a quick integration of service modules, but it could lead to performance problems, due to the introduced communication overhead. In this paper, we report our experience in developing a simple CORBA/RMI gateway module, and we discuss how it affects the application performance. Measures of the communication overhead show that the employment of the gateway is a viable solution in many real-world applications, and gives hints for efficiently placing modules on the available hosts.