Application Server Aging Model and Multi-Level Rejuvenation Strategy Using Semi-Markov Process

Aiming at the characteristic of the dependency between the application components and the application server platform, a rejuvenation strategy with two different levels of rejuvenation granularities is put forward in this paper including the application component reiuvenation and the application server system rejuvenation. The availability and maintenance cost functions are obtained by means of establishing the application server aging model and the boundary condition of the optimal rejuvenation time is analyzed. Theory analysis indicates that the two-level rejuvenation strategy is superior to the traditional single level one. Finally, evaluation experiments are carried out and numerical result shows that compared with the traditional rejuvenation policy, the rejuvenation strategy proposed in this paper can further increase availability of the application server and reduce maintenance cost.

Fujitsu's E-Business Proposal——Overview of INTERSTAGE Software Platform

The explosive growth of the Internet has caused the new medium to step past just being another means of communication, and has acted as a catalyst to cause radical changes to the nature of business. Amongst the changes, e Business, which brings internet technology to all areas of work in enterprises, is especially active. Many enterprises are showing strong interest the application server adapted internet technology, such as Web and Java, as the new platform for the next generation in enterprise computing environments. INTERSTAGE builds on the latest internet technology, and is a complete software platform centering on application server, which can support the various business applications required for e Business. In this document we cover the overview of features and functions of INTERSTAGE, and introduce Fujitsu's approach to e Business through INTERSTAGE.

Trends of Communication Processors

Processors have been playing important roles in both communication infrastructure systems and terminals.In this paper,both application specific and general purpose processors for communications are discussed including the roles,the history,the current situations,and the trends.One trend is that ASIPs(Application Specific Instruction-set Processors) are taking over ASICs(Application Specific Integrated Circuits) because of the increasing needs both on performance and compatibility of multi-modes.The trend opened opportunities for researchers crossing the boundary between communications and computer architecture.Another trend is the serverlization,i.e.,more infrastructure equipments are replaced by servers.The trend opened opportunities for researchers working towards high performance computing for communication,such as research on communication algorithm kernels and real time programming methods on servers.

A Fault-Tolerant Architecture for Parlay Application Server

As the value-added service providing system in the Next-Generation Networks (NGN), Application Servers (AS) are required to provide the carrier-class reliability. To increase the reliability of AS, the fault-tolerant technology is often adopted. This paper proposes a fault-tolerant architecture for AS against single-point faults. The result of analysis shows that the architecture has a good reliability and is easily extendable. Such an advantage is attributed to a kind of special fault-tolerant design, which is different from others in that two Service Logic Program (SLP) instances do not only provide backups to each other, but also share them in the service traffic.

On overload control of parlay application server in next generation network

After analyzing the features of the Parlay application server（AS）, which provides many services with different time constraints in the next generation network（NGN）, a selfadapted overload control algorithm implemented in Parlay AS is proposed. In this algorithm, the service process module in parlay AS uses the earliest deadline first （EDF） serving rule to serve messages, and the overload control mechanism, using the Leaky Bucket algorithm to control message flows, is triggered by estimating the queue waiting time of a newly arriving message. By simulation it shows that this algorithm is a simple, easy-to-use, and available algorithm.

Dynamic weighted random load balancing algorithm for SIP application server

A new load balancing algorithm named dynamic weighed random （DWR） algorithm for the session initiation protocol （SIP） application server cluster is proposed. It uses weighted hashing random algorithm that supports dialog in the SIP protocol to distribute messages. The weight of each server is dynamic adaptive with feedback mechanism. DWR insures that the cluster is balanced, and it performs better than the limited resource vector （LRV） algorithm and minimum sessions first （MSF） algorithm.