How to use BeanShell server to modify Jmeter's user properties while running the test

Question

I would like to control throughput in real-time while running the test. How do I do that using BeanShell server?

Basically I want to update a user property 'throughput' (used in Constant Throughput Timer) from command line while the test is running.

Solution: Based on Dmitri's answer I did the following:
1. I added to user.properties:

beanshell.server.port=9000  
beanshell.server.file=beanshell.server.file=/home/sam/JMeter/apache-jmeter-4.0/extras/startup.bsh

2. Started JMeter and my test.
3. Executed this command in Terminal:
   ~/JMeter/apache-jmeter-4.0$ java -jar lib/bshclient.jar localhost 9000 /home/sam/JMeter/beanshell/setthroughput.bsh 100
4. Value of throughput property is now 100. Fantastic!

Answer 1

1. Add the next 2 lines to user.properties file:

   beanshell.server.port=9000
   beanshell.server.file=../extras/startup.bsh
   

2. Restart JMeter to pick the settings up

3. Set throughput property in the Constant Throughput Timer using __P() function like:

   ${__P(throughput,60)}
   

   this will set default throughput to 60 requests per minute (1 request per second), if throughput property will be defined somewhere somehow - the value will get overriden.

4. Create setthroughput.bsh in "lib" folder of your JMeter installation with the following contents:

   setprop("throughput", args[0]);
   

5. In the runtime you will be able to modify the throughput like:

   java -jar bshclient.jar localhost 9000 setthroughput.bsh 100
   

   

More information: Beanshell Server

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I believe it would be easier if you switch to Throughput Shaping Timer which has load_profile property so you will be able to control throughput in more flexible and efficient manner. You can install Throughput Shaping Timer using JMeter Plugins Manager