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