Designing Dynamic Composite Media Service and Monitoring Its Run-Time Performance

Abstract

The objective of this paper is to design and implement a Dynamic Composite Media Service (DCMS) and monitor its performance through Service Monitor (SM). The media services such as translation, scaling and colour reduction services are combined to design composite Video-on-Demand (VoD) service using Business Process Execution Language (BPEL) designer and this composition can be changed during run-time based on the changes in the requirements of the user. Performance of these dynamically composed service-oriented applications has to be monitored at application and system level with the existing BPEL exception handling logic. The proposed SM, a monitoring service executed in parallel with each requested media service using multi-threading technology. SM monitors the execution of DCMS which are represented as a BPEL process. The system and application level QoS parameters such as response time, delay, external errors, Quality of Experience (QoE), Service Level Agreement (SLA) violation, percentage of successful completion of individual media services, time at which response time degrades, and media characteristics include frame rate and frame resolution have been monitored at run time. These monitored results are used to know the performance of media services in their operational environments. The effectiveness of SM has been evaluated for Dynamic Composite VoD Service and its results indicate an improvement in the performance of run-time monitoring of media services.