apache / jmeter

Apache JMeter open-source load testing tool for analyzing and measuring the performance of a variety of services
https://jmeter.apache.org/
Apache License 2.0
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Use start time of open model thread group instead of test plan start time for calculating sample start times #6352

Closed FSchumacher closed 1 month ago

FSchumacher commented 2 months ago

Expected behavior

Open model thread group should work the same when used with or without a long running setup thread group before it.

Actual behavior

When using open model thread group together with a long running setup thread group, we currently might generate sample storms.

Steps to reproduce the problem

Use the test plan contained in omtg-and-setup-group.jmx.zip

When we use the (current implementation) start time of the test plan, OMTG will think it is 10 seconds late in the game (that is how long the setup thread group made us wait) and start all samples concurrently.

With System#currentTimeMillis() as start time, we get the correct start time and the samples will be issued correctly. That is, they should be roughly issued with 1 req/s.

JMeter Version

5.7.3

Java Version

openjdk version "17.0.12" 2024-07-16

OS Version

Ubuntu 24.04.1