Responsive Computing brings together in one place important contributions and state-of-the-art research results in this rapidly advancing area. Responsive Computing serves as an excellent reference, providing insight into some of the most important issues in the field.

Finally, we strongly believe that this year's conference continued the tra- tions of having a high scienti?c and technical quality as well as an extensive dialogue on key issues of service availability. May 2008 Fumihiro Maruyama Andras ' Pataricza Organization ISAS 2008 was sponsored by the Research Center for Advanced Science and Technology (RCAST), University of Tokyo and Service Availability Forum, in cooperation with IEICE TC on Dependable Computing and GI TC on Depe- ability and Fault Tolerance. Organizing Committee General Chair Takashi Nanya (University of Tokyo, Japan) Program Co-chairs Andras ' Pataricza(BudapestUniversityofTechnologyandEconomics,Hungary) Fumihiro Maruyama (Fujitsu Lab. , Japan) Finance Chair H. Nakamura (University of Tokyo, Japan) Local Arrangement Chair M. Imai (University of Tokyo, Japan) Registration Chair M. Kondo (University of Tokyo, Japan) Publicity Chair M. Reitenspiess (Fujitsu Siemens Computers, Germany) Publication Chair M. Malek (Humboldt University, Germany) Web Master H. Okamura (Hiroshima University, Japan) Steering Committee M. Reitenspiess (Fujitsu Siemens Computers, Germany) S. Benlarbi (Alcatel, Canada) T. Dohi (Hiroshima University, Japan) M. Malek (Humboldt University, Germany) D. Penkler (HP, France) F. Tam (Nokia, Finland) X Organization ProgramCommittee A. Avritzer (Siemens, USA) D. Bakken (Washington S. , USA) R. Baldoni (University of Rome, Italy) G. Chockler (IBM, Israel) C. Fetzer (TU Dresden, Germany) F. Fraikin (SDM, Germany) R. Fricks (Motorola, USA) M. Funabashi (Hitachi, Japan) A. Gokhale (Vanderbilt, USA) K. Hidaka (IBM, Japan) M. Hiller (Volvo, Sweden) H. Ichikawa (UEC, Japan) K. Iwasaki (Tokyo Metropolitan University, Japan) Z. Kalbarczyk (UIUC, USA) T.

This book constitutes the refereed proceedings of the 4th International Service Availability Symposium, ISAS 2007, held in Durham, NH, USA in May 2007.

The 12 revised full papers presented were carefully reviewed and selected from 25 submissions. The papers are organized in topical sections on middleware, software systems, modeling and analysis, as well as model-driven development and human engineering.

much Last but not least we would like to thank Manfred Reitenspiess who has been the guiding force behind ISAS and the Service Availability Forum. I hope that the attendees enjoyed the ?nal program, enjoyed the presen- tions, got involved in the discussions, struck up new friendships, and got ins- ration for contributions to the next year s symposium which will be hosted by KimmoRaatikainen, UniversityofHelsinkiandFrancisTamofNokiainHelsinki during May 15 16, 2006. Miroslaw Malek Neeraj Suri Humboldt Universit] at Berlin Technische Universit] at Darmstadt Institut fur ] Informatik Institut fu]rInformatik malek@informatik. hu-berlin. de suri@informatik. tu-darmstadt. de ISAS 2005 General Chair ISAS 2005 Program Chair Table of Contents TTA Supported Service Availability Hermann Kopetz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 The Value of Conformance Testing and a Look at the SAF Test Project Bob Spencer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Building Highly Available Application Using SA Forum Cluster: A Case Study of GGSN Application Ajay Kamalvanshi, Timo Jokiaho. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Using Logical Data Protection and Recovery to Improve Data Availability Wei Hu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Contract-Based Web Service Composition Framework with Correctness Guarantees Nikola Milanovic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Practical Approach to Speci?cation and Conformance Testing of Distributed Network Applications Victor V. Kuliamin, Nickolay V. Pakoulin, Alexander K. Petrenko . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Model-Based Optimization of Enterprise Application and Service Deployment Andr as Balogh, Dan iel Varro, Andr as Pataricza . . . . . . . . . . . . . . . . . . . 84 On Best-E?ort and Dependability, Service-Orientation and Panacea Aad van Moorsel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Are Service-Oriented Architectures the Panacea for a High-Availability Challenge? Guido Laures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Modeling User-Perceived Service Availability Dazhi Wang, Kishor S. Trivedi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ."

Database management systems are critical components of highly available appli- tions. To meet this need, many highly available database management systems have been developed. This paper describes the architectures that are internally used to construct these highly available databases. These architectures are examined from the perspective of both process redundancy and logical data redundancy. Process red- dancy is always required; it refers to the maintenance of redundant database processes that can take over in case of failure. Data redundancy is also required. Data red- dancy can be provided at either the physical or the logical level. Although both forms of data redundancy can provide high availability, this paper has concentrated on lo- cal data redundancy since that is a case where the database explicitly manages the data copies. We believe that process and data redundancy are useful means to describe the availability characteristics of these software systems. References 1. Application Interface Specification, SAI-AIS-A. 01. 01, April 2003. Service Availability Forum, available at www. saforum. org. 2. Gray, J. and Reuter, A. : Transaction Processing Systems, Concepts and Techniques. M- gan Kaufmann Publishers, 1992. 3. How MySQL Cluster Supports 99. 999% Availability. MySQL Cluster white paper, MySQL AB, 2004, available at http://www. mysql. com/cluster/. 4. Hu, K. , Mehrotra, S. , Kaplan, S. M. : Failure Handling in an Optimized Two-Safe Approach to Maintaining Primary-Backup Systems. Symposium on Reliable Distributed Systems 1998: 161-167. 5. Humborstad, R. , Sabaratnam, M. , Hvasshovd, S-O. , Torbjornsen, O.

Responsive Computer Systems: Steps Towards Fault-Tolerant Real-Time Systems provides an extensive treatment of the most important issues in the design of modern Responsive Computer Systems. It lays the groundwork for a more comprehensive model that allows critical design issues to be treated in ways that more traditional disciplines of computer research have inhibited. It breaks important ground in the development of a fruitful, modern perspective on computer systems as they are currently developing and as they may be expected to develop over the next decade. Audience: An interesting and important road map to some of the most important emerging issues in computing, suitable as a secondary text for graduate level courses on responsive computer systems and as a reference for industrial practitioners.

Responsive Computing brings together in one place important contributions and state-of-the-art research results in this rapidly advancing area. Responsive Computing serves as an excellent reference, providing insight into some of the most important issues in the field.