LoadSimulator for performance analysis of SMTP server

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Load-Simulator for performance analysis of SMTP
server

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Objectives

• Behavioral analysis in peak load
• Behavioral analysis in persistent load
• Competitive analysis
• finding bugs (memory leak, inefficient threading
  module etc)

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Definition
Load-Simulator is a tool that simulates real time
load on the server by creating virtual users and
monitors the effect on the server.
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Flow
L-sim (10.113.11.65)
L-sim
SMTPServer (10.113.26.62)
SMTP sink (end user) 10.113.26.64
L-sim (10.113.26.27)
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Test Cycle
Virtual Users
Time
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Performance Parameters

• CPU utilization Load-Simulator gets the real
  time CPU utilization of SMTP server.
• Transaction Response Time (TRT) Load-Simulator
  records TRT throughout the test. It tells us how
  much time the server takes to process one
  request. With increasing load, it ideally keeps
  on increasing.
• Messages Per Second (MPS) MPS is another
  performance measurement criterion of SMTP server.
  With more users coming in, ideally MPS should
  increase. With most servers after a certain time
  (load), MPS does not change, indicating the peak
  load.

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Technical details

• Most part of Load-simulator is developed in
  java.
• Virtual users are implemented as java threads
• Remote invocation is achieved by TCP socket
  server. The client need to know in advance what
  IP address and port the server is running. Other
  forms of remote invocation like java RMI, CORBA
  etc would have been ideal as they use tighter
  security.
• CPU utilization This is real time CPU
  utilization. Achieved in C for windows platform
  by digging through the registry.
• TRT One complete transaction from client to
  server.
• MPS Rate at which messages are received at SMTP
  sink. (urlreader good example of web script)

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Important tips

• To explore full potential of the server, do not
  have any major service running on the server
  other than one being tested
• Remover bottleneck
• 1) client
• 2) network bandwidth/traffic

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Snap shots

• http//www.cs.odu.edu/khanv_s/master_project/

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Further development.

• Load simulator is a basic skeleton that does most
  of the full fledged functionality. Much can be
  done on the client side to make it more user
  friendly.
• Data (TRT, MPS, Cpuusage) right now is reported
  in text file. This can be plotted in graph. A
  real time plotting of graph is ideal.
• Load simulator can be implemented on any server
  (database, web server etc). The client just need
  to know in advance the API to talk to.
• The cpu usage works on windows platform. If the
  server was hosted on Linux or Solaris platform we
  need to make use of rstatd statistics.

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References

• http//msdn.microsoft.com/library/default.asp?url
  /library/en-us/perfmon/base/perf_100nsec_timer_inv
  .asp
• http//www.mercuryinteractive.com/
• http//www.cs.odu.edu/7Ecs476/SocketProgramming/j
  ava/java.htm