Learning center
Case study: J. Walter Thompson
Advertising agency
“Load Impact’s service allowed us to load and stress test an advertising campaign and helped us successfully prepare for high traffic volumes”
Executive summary:
JWT used Load Impact to perform load tests to verify that their new campaign site could handle 120,000 visitors/hour.About the customer:
JWT is one of the largest advertising agencies in the United States and the fourth-largest in the world. JWT’s network has nearly 10,000 employees in more than 200 offices in over 90 countries, who serve over 1,200 clients.
Case:
Load Impact were commissioned by JWT to establish that the backend for a new campaign web site could handle the expected traffic – 120,000 visitors per hour – while exhibiting load times that were within acceptable limits.
The campaign-site has a user signup/login procedure and offers an interactive online game. The backend for the service is hosted in Texas, and all static content is distributed through a CDN which makes calls to the backend servers. There is also an external partner which handles the user database including registration, signup etc.
Test set up:
For the purpose of testing the backend only, a set of specific user actions were defined, such as “user registration”, “user sign-in”, and other actions where the backend systems had to be involved. These actions were activated through requesting certain URLs, one for each type of action, that were created specifically for the load test. In practise it meant that a simple API was created only for running the load test.
The simulated users in the test were configured to perform a series of these predefined user actions, resulting in corresponding calls to the backend systems. The static content, normally served through CDN operators, was ignored in the test.
The test was run as a series of ramp-up tests, individually tuned depending on results of previous tests, and designed to find out the breaking point of the target system.
Service environment:
- Apache
- PHP
- MySQL
- Linux
The tested environment consisted of an HTTP load balancer plus web-, application- and database servers.
Challenges:
- Validate that the system could handle the expected amount of traffic
- Detect potential problems in the infrastructure or web app
- Establish a performance baseline
Solution:
- Load generation and measurements from multiple geographic locations
- Application response time, throughput and customer experience analysis provided for JWT
Results:
- Baseline established at about the required level of 120k visitors/h
- No specific performance problems found. The external service provider of user registration and sign-in functionality had no problems and their response times remained constant during the test while the other backend services exhibited response times that were stable until just over the required level of 120,000 visitors/hour, after which response times started to increase rapidly and exponentially
- The conclusion was that JWT could go ahead with the launch
The campaign site was launched successfully on Youtube on August 31, 2011
Site link: http://www.youtube.com/zyrtec