I have saved the HTTP Header Manager information for an endpoint as below:
However, when i execute this test plan i see in the test results tree view, many of the hits fail. I figure from the response headers i see there that it is using the header value i had put in earlier.
Why are these history values being used? How do i get rid of it.
Check the request start time, it might be the case you're looking at "old" results and you need to scroll down to see "new" results. Alternatively you can invoke Clear all
menu entry which will remove all the previous results, logs, etc.
Running tests in GUI mode should only be used for development and debugging, for your 100 threads you should switch to command-line non-GUI mode
Also when you're done with designing your test consider removing all the listeners as they don't add any value and just consume valuable resources. More information: Reducing resource requirements