1. January 16th,20061 Performance Engineering of Distributed Systems and Wireless Networks Varsha Apte, CSE Dept., IIT Bombay Collaborators: Profs Bellur, Iyer (KreSIT), Manjunath (EE) UNSW Workshop January 16 th, 2006

2. 2 Ongoing Research Two threads of work Distributed Systems Performance Wireless Networks (mainly 802.11 family of LANs) At the core: Performance point of view, using models or measurement.

3. January 16th,20063 Distributed Systems: Context Internet (Multi-tiered, heterogeneous, geographically distributed, Web front-end ) End Users Server System Multiple Use cases QoS expectation s Data center cost optimization

4. January 16th,20064 High-level performance analysis tools Goal: To go from here: User WebAuth IMAP login/passwd is valid invalid re-login valid display inbox messages list of messages Inbox listing 0.1 0.9 Sync + auth web imap smtp imap auth LAN 1 LAN 2 Physical server 1 Physical server 2 Physical server 3 Network delay + resource profiles + workload profile

5. January 16th,20065 High-level performance analysis tools To here: Tool does transformation to queuing network and its analysis[6]. (Both Simulation and Analytical Engine)

6. January 16th,20066 Related Research Tool for generating resource consumption profile (Auto profiler) Tool for generating message sequence charts (Prof. Umesh Bellur)  Both are inputs required in the performance analysis tool

7. January 16th,20067 Generate Load Profile Servers 1 2 3 Collect client statistics Collect server statistics Client Correlate & display Autoprofiler M S S S S Master – Slave Architecture Slaves profiles the servers. Master co-ordinates the process. Autoprofiler [1] Servers

8. January 16th,20068 Overload/Admission Control of Distributed Systems Goal: To develop self-tuning, self- configuring control that can guarantee QoS levels to users of software services Preliminary results: Using LIFO queuing discipline in a Web-server at overload. w/ Prof. D. Manjunath [2]

9. January 16th,20069 Wireless LANs Capacity, performance (802.11b) Admission control (801.11e) Location Determination (802.11b)

10. January 16th,200610 Sizing Methodology for 802.11b WLANS n* n* : Number of users that should be in “one LAN” Sizing algorithm using analytical models [4]

11. January 16th,200611 Admission Control in 802.11e WLANS PLUS-DAC: Priority, Load, Utilization based Scheme for Distributed Admission Control, w/Prof. Sridhar Iyer [3]

12. January 16th,200612 Location Determination using WLANs Goal: to improve on accuracy of existing WLAN based location determination systems Improvement using multiple observers technique [5]

13. January 16th,200613 Future Directions Distributed Systems Continue Tool Development (w/ Prof. Umesh Bellur) for Performance analysis of distributed systems extend to model details of J2EE systems Software QoS in Shared Hosting Centers – self tuning mechanisms Wireless Networks Protocols and their analysis for mesh networks QoS in Wireless LANs – measurements on real testbeds Location Determination: develop applications

14. January 16th,200614 References 1. B. Nagaprabhanjan and Varsha Apte, “ A tool for automated resource consumption profiling of distributed transactions ”, in Lecture Notes in Computer Science, Springer-Verlag - Proceedings of the International Conference on Distributed Computing and Internet Technology (ICDCIT), Bhubaneshwar, India, December 2005.A tool for automated resource consumption profiling of distributed transactions 2. "A Combined LIFO-Priority Scheme for Overload Control of E-commerce Web Servers", Naresh Singhmar, Vipul Mathur, Varsha Apte and D. Manjunath, Proceedings of the International Infrastructure Survivability Workshop (affiliated with the 25th IEEE International Real-Time Systems Symposium), Lisbon, Portugal, 2004. "A Combined LIFO-Priority Scheme for Overload Control of E-commerce Web Servers" 3. Kiran K. Gavini, Varsha Apte, Sridhar Iyer, “PLUS-DAC: A Distributed Admission Control scheme for IEEE 802.11e WLANs“, in the Proceedings of the International Conference on Networking (ICON), Kuala-Lumpur, Malaysia, November 2005. 4. Preetam Patil and Varsha Apte, “Sizing of 802.11 Wireless LANs”, in the Proceedings of the ACM Workshop on Mobile Applications and Services in Hotspots (WMASH), Cologne, Germany, September, 2005. 5. Raman Kumar K, Varsha Apte and Yogesh Powar, “Improving the accuracy of WLAN based location determination systems using Kalman filter and multiple observers”, to appear in WCNC 2006, Las Vegas, USA. 6. Rukma P. Verlekar, Varsha Apte, “A Methodology and Tool for Performance Analysis of Distributed Systems”, to appear in the Emerging Research Track of the International Conference on Software Engineering, Shanghai, China, May 2006.