Load Impact and MTGx Prepare for 2013 Winter Olympics

MTGx approached Load Impact before the 2014 Winter Olympics to ensure their streaming service could withstand hundreds of thousands of Swedish sports fans flocking to their site.


MTGx is the digital accelerator of Modern Times Group, and is focused on leveraging MTG’s digital assets and industry leading content portfolio, to create and deliver world class entertainment experiences.

In the fall of 2013, they acquired the rights to broadcast the 2014 winter Olympics throughout Sweden.

With Sweden being quite competitive in winter sports, MTGx expected there to be a significant amount of traffic accessing their various sites as well as the live streaming offered on os.viaplay.se.

The Project Scope

Load Impact was commissioned to help excite a series of performance tests aimed at
stressing several worst case scenarios. The worst case scenarios were:

  • Score is tied during the last minutes of the hockey finals Sweden vs Canada

  • Terrestrial broadcast is interrupted

  • In a panic, 4 million users flood to tv3.se in a few minutes to find where they can stream the event online

  • Test setup

    Simulate the average user load on the tv3.sehomepage and then execute a sudden usage
    spike before users click the link to the olympic website - os.viaplay.se. Expected 30,000
    concurrent users at peak usage.

    Spike test in excess of 1 million users who will hit thetv3.sehomepage, which should be fully cached in varnish.

    Test to see where the bottlenecks are, fix and then retest to confirm the improvements.

    The test covered:

  • os.viasatsport.se

  • sotchijunior.se

  • tv3.se

  • Test environment

  • At least 2 Varnish caching servers (HTTP reverse proxy)

  • Standard Apache backend

  • Several integrations and CDNs

  • MySQL database

  • Memcache

  • Wordpress CMS for Viasat sport and Sotchi sites

  • Results: os.viasat.se and SotchiJunior.se

  • 3 different load test were run for Sotchijunior.se and os.viasat.se, which are hosted on the same environment

  • One test exercised both sites at the same time with load evenly distributed between
    both. Goal was stability at 50 000 concurrent users

  • os.viasat.se test went fine, it was the Sotchijunior site that proved problematic

  • During this first test of both sites a bug was discovered in the Sotchijunior site (the site
    had yet to launched)

  • The bug was that the request went directly through the caching layer hitting the backend

  • Load Impact then removed the requests that went directly through the caching layer
    hitting backend from the load test script and re-ran the test only against Sotchijunior

  • After re-running the Sotchijunior test, results showed it was working great and could
    handle at least twice the load it could handle in the first test (the first test was 7,500
    concurrent users and the second test showed it could handle 20,000 concurrent users)

  • The third test was run only against os.viasat.se and was successful. It could handle about 50,000 concurrent users with an under 3 seconds load time

  • As a result of testing with Load Impact

  • Discovered problem: CDN provider seemed to have stripped deflate headers, which
    means all the content was delivered in plain text rather than Gzipped. Which made it
    much more bandwidth intense for the communication between the Varnish and the CDN

  • Discovered bug with SotchiJunior.se site that had requests go directly through the caching layer hitting the backend

  • As a result of the testing, MTGx’s hosting provider BaseFarm did a lot of Varnish tuning
    between test iterations because they were able to keep and reuse the tests scripts
    created with Load Impact team

  • Because of our hard work, the resounding success of the project and MTGx being great partners, ComputerWeekly recognized the effort as the Best Private Sector Project of the Year in its annual European User Awards. Click the award banner above to read more about what into the project.

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