need to rewrite HTTP 200 status code to HTTP 503

Richard's right and has a good example. I missed that you wanted to just rewrite the pool member's status code.

 

 

There's an existing Request For Enhancement for rewriting the status code using HTTP::status $new_status_code:

 

 

BZ385613 RFE: Make HTTP::status iRule command support writing data

 

 

You can open a case with F5 Support to add your request to the RFE and raise its visibility.

 

 

Aaron