Check when no output produced

[#1]

I would like to be able to check when a Nifi processor run successfully  but without producing any output, i.e.,  nothing passed to the downstream process for further processing.  I would like to configure an email notification that no output produced by the processor.   Any help would be appreciated on how to make such a  Nifi validation process to so such check  generating one-line text, such as "Nothing produced by XYZ processor"

[#2]

hi @Love-Nifi 

can you please let me know which processor you are trying to use?

[#3]

This is the actual processor being used:  ExecuteScriptMarkLogic 1.8.0.3.   When thing returned from XQuery script, no output generated for next flow.  

[#4]

Basic the Xquery does not return anything (null return)

[#5]

@Love-Nifi 

As @Magudeswaran  mentioned it depends on the concrete processor you are using and the format of the response you are expecting.
For example after an ExecuteSQL I check the content this way using RouteOnContent.

Check no-content