Performance Engineering of Distributed Systems and Wireless Networks

1
Performance Engineering of Distributed Systems
and Wireless Networks

• Varsha Apte, CSE Dept., IIT Bombay
• Collaborators Profs Bellur, Iyer (KreSIT),
  Manjunath (EE)
• UNSW Workshop
• January 16th, 2006

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
Distributed Systems Context
(Multi-tiered, heterogeneous, geographically
distributed, Web front-end)
Internet
Multiple Use cases
End Users
QoS expectations
Server System
Data center cost optimization
4
High-level performance analysis tools

• Goal To go from here

resource profiles workload profile
5
High-level performance analysis tools

• To here

Tool does transformation to queuing network and
its analysis6. (Both Simulation and Analytical
Engine)
6
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
Autoprofiler 1
S
Servers
S
M
Client
Generate Load
S
Profile Servers
S
2
1
Autoprofiler

• Master Slave Architecture
• Slaves profiles the servers.
• Master co-ordinates the process.

Collect client statistics
3
Collect server statistics
Correlate display
8
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
Wireless LANs

• Capacity, performance (802.11b)
• Admission control (801.11e)
• Location Determination (802.11b)

10
Sizing Methodology for 802.11b WLANS
n
n Number of users that should be in one LAN
Sizing algorithm using analytical models 4
11
Admission Control in 802.11e WLANS
PLUS-DAC Priority, Load, Utilization based
Scheme for Distributed Admission Control, w/Prof.
Sridhar Iyer 3
12
Location Determination using WLANs

• Goal to improve on accuracy of existing WLAN
  based location determination systems

Improvement using multiple observers technique 5
13
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
References

• 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 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.
• 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.
• 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.
• 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.
• 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.