When we using JMeter Remote testing, more than one slave
machines are running the same tests and the test results from all of the slave
machines will record in the client machine. Aggregate.jtl file will save all of
the test results and we can analyze the results from the .jtl file information.
But I found one more issue at here. The
number of threads (Virtual Users) is not matching what we expect. For example,
We have 2 slave machines to run our test; each slave machine
will run 100 threads, so we totally use 200 threads. And after we run the remote tests in the two
slave machine, we saw 200 samples but only 100 thread records in the .jtl file,
rather than 200 samples and 200 threads.
Why?
This is because the 2 slave machines running the exactly the
same test with the exact same Thread Group Name, so in the .jtl file, they
can’t figure out which thread group is coming from slave machine 1 or slave
machine 2, so it thinks they have the same thread group name, so they are the
same thread, rather than two different threads.
How to solve this issue and make the .jtl result file have
the correct thread number?
The solution is we need to let the thread group
name is different and .jtl will know it comes from which slave machines. So we need to change the thread group name
from the static name to be a dynamic name with slave machine ip or name. The functions ${__machineName()} and ${__machineIP()} are our key to solve the problem.
If you are doing
distributed tests, you should name the thread groups like this in your test
plan:
${__machineName()}_My Threadgroup name
Or
${__machineIP()}_My Threadgroup name
After modified the thread group name in the test plan, in
the active threads over time listener, we can see each test thread in the test
plan are records according to the running slave machines like this
The follwing link is helping to fix my # of threads issue. :)
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