avoid cookie duplicate in jmeter with JSR223 preprocessor - cookies

Question

I am using a JSR 223 preprocessor to generate cookie from a text file and it works just fine. However, this cookie gets duplicated on every HTTP sampler request i have.
How can i avoid this ?
My testplan structure is :
testplan
-CookieManger
--testFragment
---JSR223 PreProcessor
----Transaction controller
-----HTTP request1
-----HTTP request2
-----HTTP request3
-----HTTP request4
in the first http request the cookie appear just once, however on HTTP request 2,3,4 the cookie is duplicated 2,3,4 times even though i checked the "clear cookie each itteration" in the cookie manager. How can i avoid this ?
Please note i'm a beginner to jmeter

Answer 1

Be aware of JMeter Scoping Rules, given the current placement of the JSR223 PreProcessor it will be executed before every HTTP Request sampler.
The easiest workaround is just moving it to be a child of the HTTP Request 1
Alternatively you can check the presence of cookie and add it only if it's absent, something like:
if (sampler.getCookieManager().getCookies().find { cookie -> cookie.getName().equals('your-cookie-name-here') } != null) {
//the code to add cookie from the text file here
}
More information: Modifying Cookies in JMeter with Groovy