How to prevent the unexpected delays that occur in Jmeter, when multiple thread groups are executed at a time or even when executed consecutively

Question

For performing a 1Hr Soak Test, I have two thread groups, First thread group to execute GET token and the next thread group to VALIDATE the access token which is generated in the previous thread group's GET token

I want to achieve this outcome:

GET token to be executed once to fetch the access token, and VALIDATE token to use that same access token and validate "N" number of times, N= 4400

In my GET Thread Group I have added a bean shell processor- to convert the access token into a JMeter Property via __setProperty() function

In Validate Thread group I have accessed property by function ${__P(some-property-name,)}, included a constant throughput timer with values of 73/min and have also set a throughput controller with total no of executions to 4400, have kept duration to 3600Sec

Still When I execute this I'm Not able to reach the expected no of transactions, Actual result is just 900 requests, there is a huge delay in processing the No of Samples....

It would be really helpful if I get help with suggestions on understanding.....What can be the reasons behind such delays, How to avoid this unexpected delays in Jmeter, what other options are available in Jmeter to prevent a delay while executing Multiple Thread Groups either consecutively or while executing all at once?

Answer 1

If you want to execute 73 requests per minute it means that response time must be 1.2 seconds or less.

1. So first of all take a look at average response time using i.e. Aggregate Report listener

2. Constant Throughput Timer has several modes, the one you're looking for is All active threads

   

3. You might need to increase the number of threads in the Thread Group which executes VALIDATE request if one virtual user is not sufficient

4. Make sure to follow JMeter Best Practices

5. If you're absolutely sure that JMeter is the bottleneck you can consider allocating another machine and run JMeter in Distributed Mode

6. Since JMeter 3.1 it's recommended to use JSR223 Test Elements and Groovy language for scripting so consider migrating. If you're using it only for converting a variable into a property and doing it only once - it should be fine, but for heavier tasks consider using Groovy.