how to set proper ramp-up time in jmeter?

Question

I am new to jmeter, I want to create a report, I have following doubts:

1. I want to find out the maximum number of users that can be given in a thread for ramp-up time 1sec?

Ex: 5 simple Http Request no of user : ? Ramp up time = 1 Loop=1

1. How to set a proper ramp-up time depending on the number of user in a thread?

Ex: 5 simple Http Request no of user : 100 Ramp up time = ? Loop=1

I tried different combinations of ramp-up and number of users considering through put , but the results varies and not able to find out a relation with the ramp-up time and the number of users.

Please help to find a solution for it.

Thanks!

Answer 1

Ramp-up period is the time required for all threads representing virtual users to start.

JMeter starts with 1 user and kicks off another thread so all threads will start in ramp-up period time slot i.e.

• 10 users, 10 seconds ramp-up - start with 1 user, each second 1 user added
• 10 users, 20 seconds ramp-up - start with 1 user, each 2 seconds 1 user added
• 100 users, 50 seconds ramp-up - start with 1 user, each second 2 users added

Keep in mind that if the thread has finished its job and there are no loops defined it'll shut down. For JMeter greenhorns it's better to use Ultimate Thread Group (available via plugin) which provides easy-understandable and configurable load pattern definition.

Depending on what you're trying to achieve you can also use the following test elements:

• Synchronizing Timer - to hold the threads until specified number will be reached and release them at the same moment
• Constant Throughput Timer - to specify exact load in requests-per-second.

Hope this helps.