Where does the POST data from a xas post come from?

We are trying to automate a testscript in JMeter for loadtesting. Login is working succesfull and we receive the object data and page data. But at the next page some XAS posts are done with a queryId. This queryId is different, each time you load the page. But we cannot find the origin of the queryId: where does it come from since it is not present in the received data? When a static value is used, a 403 error is received. In the logging the following error is noted: [APP/PROC/WEB/0]   ERROR - Connector: com.mendix.webui.WebUIException: Attempt to illegally change a value for object with id '<objectid>' (PROCESS_Xx.Xx). Object hash is invalid! Does someone has a clue where we can find these specific values? Or some documentation on how the pages are built with Mendix? Thank you!
1 answers

As others have pointed out it is not easy to get these query ids. As they are internal Mendix technology they are not documented anywhere and are frequently changed by Mendix R&D as part of their ongoing effort to optimize the performance and security of the platform.

Mansystems offers a load testing service specifically for Mendix, might be interesting for you https://www.mansystems.com/smart-digital-factory/tooling/load-testing