The adCenter Display Ads Platform team recently ran a large test using VSTS. The goal of this testing was to validate the configuration and stability of 100+ servers under load.
The test used one Controller and 42 agents to produce the necessary load. The controller was also hosting a full install of SQL Server which acted as the result store.
Controller and Agent hardware information
Processor: 4 x AMD Opteron 280 (2405 MHz)
Memory: 4 GB RAM
Network: GigE NIC
High level test summary
Test Duration 12 hours
Total requests generated 3,639,518,000 (3.63 Billion requests)
Average requests/sec 84,248
Average Requests/Test 1
Failed Tests 0
Sampling rate 30 secs
Average agent Proc utilization 45%
To minimize the risk they started off with one controller and one agent, then increasing to 8 agents, then going to 42.
They estimate they could have produced at least 50% more requests with 42 agents but restricted the load to avoid any agent overloading.
A note from the customer: Overall it was a happy experience running a test of this large scale. Thanks to VSTS for making load testing a pleasure!