TestCase / Groovy script -> LoadTests / Log display missing

Hi,

i'm performing a load test on a soap service.

load test Architecture :

Test Suite
Test step
properties
myService
Groovy script
Load Tests
LoadTest1

The groovy script i declared on the test step display the log i asked him to. -> OK

However, when time come to load test with a few amount of threads, no logs are displayed (in any log, but we are expecting logs in the script log). -> NOK
When the number of thread is set to 50+, i get only a few part of the logs. -> NOK

Is it a magic option to set on on the interface to get all logs? -> MY QUESTION

Do not hesitate to ask for further informations.

My best!