By default, a JMeter thread sends requests without pausing between each request. We recommend that you specify a delay by adding one of the available timers to your Thread Group. If you do not add a delay, JMeter could overwhelm your server by making too many requests in a very short amount of time.
The timer will cause JMeter to delay a certain amount of time before each sampler which is in its scope.
If you choose to add more than one timer to a Thread Group, JMeter