Few transaction are getting failed while I am executing my performance script

Question

I am new in Performance testing. I am using Jmeter. I have 15 transaction in my test plan and I am running the script for the 40 loops. Some of the transactions are getting failed 3 or 2 times out of 40 loops. So here what would be the possible reason for the failure.

1. Is there anything wrong in Scripting side
2. Do I need to use think time in script to avoid these errors

Answer 1

1. You need to check your target server utilization like CPU, Memory and IO. Check if the errors are connected to resources.
2. Check the target server logs for further investigation.
3. If you doubt that script is at fault make sure that you have correlated all the dynamic values but as you say they are failing 2-3 times out of 40 it means the JMeter script is working fine.
4. Adding think time may help reduce the errors but you need to design your performance test considering real life scenario and accordingly add think time.