Jmeter thread groups -

i have entered 500 number of thread group , ramp time 120 seconds when report generated,the virtual users count 15 or in composite graph-active threads on time raised near 12. bit confuse active threads counts. because data(threads) or numbers filled in test plan before test different , after result different. scaled values in graph?and x10?something related threads?

each jmeter thread representing virtual user after initialization starts executing samplers upside down (or according logic controllers).

if thread doesn't have more samplers execute , no more loops iterate it's being shut down. looks case. see max users lower expected article more detailed explanation , workaround.

usually people set loop count "forever" , use runtime controller test finish in designed time. option using i.e. ultimate thread group available via jmeter plugins provides convenient way of defining load scenario.