KBI 311305 Message API HttpSendRequest Failed Can Happen When Doing Load Testing
Version
Argent Defender all versions
Date
Monday, 26 October 2015
Summary
When simulating more than 100 virtual users for load testing in Argent Defender, following message can be seen in task log many times:
(VUser# nnn) API ‘HttpSendRequest’ failed (http:…)
It is normal behavior for load testing
The virtual users encountering such API errors are those that are for generating loads only
When Argent Defender Engine simulates so many virtual users and generate so much network traffic, the machine NIC can be saturated
As a result, the WININET API calls might not be successful all the time
But that is expected
Argent Defender does not use the performance data from these virtual users who are intended for load generating only
Instead, Engine collects the performance data only from the virtual users that actually run the web session scripts
However, when NIC is saturated, the web session scripts might not be running successfully either
For heavy load testing, it is recommended to run the virtual users for load generating on a separated Trusted Agent other than the Engine that plays the actual web session script
Technical Background
N/A
Resolution
N/A