java - Is it required to use jp@gc - Throughput Shaping Timer when you are using bzm - Concurrency Thread Group in JMeter?

Question

Good day! I'm using JMeter to do load testing. It's my first time to use this tool. I'm confused with some aspect of JMeter. I will be using bzm - Concurrency Thread Group to simulate traffic to the server. Based on documentation, it must be required to used it along with jp@gc - Throughput Shaping Timer. However, I'm thinking not to use it. Will there be any problem in my during my test? bzm - Concurrency Thread Group

question from:https://stackoverflow.com/questions/65894647/is-it-required-to-use-jpgc-throughput-shaping-timer-when-you-are-using-bzm

Answer 1

Not necessarily.

• Concurrency thread group is responsible for starting/stopping threads (you can think of them as of virtual users), like "I want to have 100 concurrent users for 10 minutes"
• Throughput shaping timer is responsible for producing throughput, the load in terms of requests per second, like "I want to have 100 requests per second for 10 minutes"

So:

1. When you operate with "users" you cannot guarantee the number of requests per second which will be generated (see What is the Relationship Between Users and Hits Per Second? for more details if needed)
2. When you operate with "throughput" you cannot guarantee that the number of users will be sufficient for conducting the required load.

So you don't have to use the Throughput Shaping Timer, you can if you want to reach/maintain the load certain number of requests per second and want to make sure that the number of threads is sufficient as they can be connected via Feedback Function so JMeter will be able to kick off some new threads if the current amount is not sufficient for conducing the required load