问题
We've a distributed JMeter setup as described here - How to Change JMeter´s Load During Runtime
The test plan (JMX file) is provided by the user. Hence, we don't know the property names used in there. During runtime, the user can provide property names and values that we will directly pass to JMeter setup through beanshell script.
In this setup, can we put a limit/cap on values of certain JMeter properties (which can potentially affect our provided resources) that can be changed by the user at runtime?
For eg. we don't want the total RPS of the system to cross say, 300 RPS at anytime. Or if the user has provided runtime change capability of #threads, we don't want them to exceed say, 100 on any machine at anytime.
We want to refrain from storing any user-defined property names in our system to provide such validation.
回答1:
You can inject a Constant Throughput Timer or a Precise Throughput Timer or a Throughput Shaping Timer into the user-provided .jmx script and put your maximum allowed concurrency there.
Even if there will be multiple timers in the test plan JMeter will apply the throughput of the slowest one so you won't make the test too fast in case if original RPS is lower than your maximum and vice versa, no matter what RPS user will want it will never get higher than 300 RPS which you will define.
The same approach applies to the number of threads in thread group.
来源：https://stackoverflow.com/questions/63664782/limit-values-of-custom-jmeter-properties-at-runtime