Abstract
The increasing importance of distributed object-oriented environments for use in parallel and distributed service frameworks has increased interest in efficiently supporting for remote-invocation frameworks, since this layer appears to be a promising paradigm for supporting ubiquitous component communications in heterogeneous network environments. This is also the layer where the well-known software layers such as Java Remote Method Invocation (RMI), .NET Remoting, and CCA remoting are located. In this paper we present novel methodologies for enhancing the streaming capabilities of Java RMI. Our streaming support for Java RMI includes the pushing mechanism, which allows servers to push data in a streaming fashion to the client site, and the aggregation mechanism, which allows the client site to make a single remote invocation to gather data from multiple servers that keep replicas of data streams and aggregate partial data into a complete data stream. In addition, our system also allows the client site to forward local data to other clients. Our framework is implemented by extending the Java RMI stub to allow custom designs for streaming buffers and controls, and by providing a continuous buffer for raw data in the transport layer socket. This enhanced framework allows standard Java RMI services to enjoy streaming capabilities. In addition, we propose aggregation algorithms as scheduling methods in such an environment. Preliminary experiments using our framework demonstrate its promising performance in the provision of streaming services in Java RMI layers. Streaming RMI utilizes 85% of bandwith in Ethernet LAN, and reduces data overhead caused by standard RMI when it is deployed in a streaming application. The simulation indicates the average waiting time is improved when our aggregation policy is applied.