并发多媒体负载访问存储系统的模型分析

多媒体应用要求存储系统提供满足服务质量QoS(Quality of Service)需求的数据访问服 务,反应时间超过截止期限的访问请求必须小于一定的比例.在开放环境下,并发多媒体负载中访问请求的随机性增加了实现这一目标的难度.并发多媒体应用的访问请求经汇聚后到达存储系统的过程服从泊松分布,存储系统的服务时间服从指数分布;并发多媒体负载访问存储系统的过程用M/M/1排队论模型描述.通过对该模型的分析推导出构成并发负载的多媒体应用数量N与负载中访问请求的响应时间分布之间的关系.仿真试验的结果证明该模型对于保证并发多媒体应用的QoS是非常有效的.

Analysis of model of concurrent multimedia workloads retrieving data form storage systems

The multimedia applications need the guarantee of the QoS(quality of service) when retrieving data form the storage systems, the fraction of requests whose response time exceeds a specific delay limit must below a certain proportion. In the concurrent multimedia workloads, many applications access a storage system at the same time, Which makes it difficult to satisfy the QoS requirements. The aggregate requests of concurrent multimedia applications Poisson arrive the storage system, the storage system service time is exponential distribution, such stochastic process was abstracted as an M/M/1 queuing model. Based on the queuing model, the relationship between the number of concurrent multimedia applications and the statistical distribution of the requests response time was determined, the relationship can be used to guarantee the QoS of concurrent multimedia applications. The experimental results validate the novel model is accurate.