It is a timer which can create large amount of load by blocking some number of threads and releasing them when the blocked thread reaches a specific value.
The listener can be used to store response in a file. The file-format depends upon the response from the server.
/test: creates a test file inside the current directory in the path
Q. What happens when Time elapsed increase the timeout value but the number of simulated user does not reach the aforementioned value?
The Synchronizing timer releases the thread whenever one of simulated user or timeout value reach the mentioned value. If timeout value is reached before the simulated user reach the mentioned value then all the threads will be released.
If the simulated user does not reach the mentioned value, and the timeout value is 0 then the jmeter enters the pause state and can only be stopped forcefully.
Name: It can be used to name the timer.
Number of simulated user to group by: The value in this field should be equal to the number of thread load that needs to be created. For e.g. if the value is 3 , then timer will block every thread until the number of blocked thread reaches 3 but as soon as it reaches 3 the thread will be release simultaneously. It is a mandatory field.
Timeout in milliseconds: This is the time by which the timer will wait before releasing any blocked threads. It is a mandatory field.