This document introduces WebStress, a tool for load testing and benchmarking web applications. It discusses recording scripts from live browser traffic, customizing scripts, defining tests with multiple scripts, running benchmark tests, and validating results. Exercises are provided to demonstrate recording a script, editing a script, creating a test, running a benchmark, and using debug mode. WebStress allows load testing for performance evaluations on applications like TrakCare without requiring expensive tools.

1. WebStress Academy
Bill McCormick & Pat McGibbon
Global Summit 2011

2. WebStress Academy
• Agenda
– Introduce the tool
– Record a script
– Edit the script
– Randomization
– Define a test with more then one or more scripts
– Execute a benchmark run
– Validate the run

3. What is WebStress
• A utility being shipped as part of the product in 2011
• A tool that allows for recording http traffic between any client
and server that supports running thru a proxy
• Allows for customizing and randomizing the data being
utilizied from a given recorded base script
• Can play back multiple recordings simultaneously to simulate
load and verify results, including performance metrics

4. Why WebStress?
• TrakCare performance evaluations required for certain bids
– Brisbane
– Edinburgh
• LoadRunner and other tools for this can be very expensive
• Managing CSP / Zen based applications requires a few little
tricks to benchmark correctly
• Has been used in dozens of benchmarks since 2002

5. Some core concepts
• Controller
– Manages the playback of a test and gathers results
• Generator
– Machine that is executing the script and randomization logic
during playback. Can be same machine as controller
• WebServer
– The URL that the application is running over. In the case of a
Cache system it also allows us to connect to the server
• App Server
– The actual database being used by the test under Cache

6. Continued
• NoEncrypt Flag
– Sets the flag that allows benchmark recordings and
playback to work on CSP / Zen based solutions
• No Delay
– For non page content ignore recorded delays
– js, html, css, jpg etc
• No Results
– For non page content ignore results
– js, html, css, jpg simulates cacheing

7. Continued
• Scripts
– A collection of http requests that from a UI perspective
represent a “transaction” or “workflow”
• Tests
– A collection of scripts that when combined represent a
“server usage profile”
• Save Page Source
– For verification purposes this will loop over a script and
save the returned page content to a local directory

8. Recording
• WebStress has a facility that launches a listener on a defined
port
• A browser for example can be configured to use this port as
a proxy and we capture the output
• We will offer to set the no encrypt flag for a given cache
service when the listener is launched
• The recorder also generates a routine for providing
randomization logic
• Exercise 1

9. Customizing a Script
• Once a recording is completed we can edit it to change settings and
values or completely randomize data being used
– Parameters
• These are name value pairs that were submitted via http
– Http Headers
• This is the information your browser added to the http request when it
was POSTed or GET
– URLs
• These are the individual http requests captured. They can be removed
or manually added
• Exercise 2

10. Creating a Test
• Controls the playback of the various scripts
– Scheduled
– Start now
– Run time
– Warm up / Cool down
– Using Delays
– Page Source

11. Tests Continued
• Adding Scripts
– Select a script
– Choose a Web Server
– Define the rate
• Sessions
• Processes
– URL Loopback
– Target
• Repeat as needed

12. Tests Continued
• Adding Scripts
– Select a script
– Choose a Web Server
– Define the rate
• Sessions
• Processes
– URL Loopback
– Target
• Repeat as needed
• Exercise 3

13. Running a Benchmark
• Preparing a Test
– Starts the processes on the Generator
– Starts the controller’s listener that drives the generators and collects
the data
• Run the Test
– The Controller sends the start signal to the generators
– Results are ignored for the duration of the “warm up”
– Live results display on this page
• After the test
– Results are processed
– Jobs Halted

14. Running a Benchmark - Cont
• While the test is running you will see information on the current Rates Per
Minute. These are color coded to indicate how close to your target for a
given script you are doing.
• If you need to you can stop a test, adjust the settings for the Sessions and
Processes and rerun the test again to aim closer to target

15. Continued
• Exercise 4

16. Debug Mode
• You have the option to run a script and have the returned pages be stored
to disk. This is very handy for debugging a script and validating that things
are performing correctly.
• To do this we specify the Source Directory and the Save Page Source
options in the test settings.
• This creates a structure at that location that represents each script, and
each time we looped thru the URLs

17. Continued
• Exercise 5

18. WebStress Summary
• Runs on 2011.1
• Can be used against any http based application
• Https not supported at this time
• Keep Alive must be disabled during recording

19. WebStress Academy
• Thank you
• Bill McCormick - bill.mccormick@intersystems.com
• Pat McGibbon - pat.mcgibbon@intersystems.com
• Iain Bray - Lead developer

20. WebStress Academy
Bill McCormick
Global Summit 2011