How to handle errors if contents of response are dynamically generated?

Hi, I am developing a HTTP server and most of requests the server gets are for large size contents that are dynamically generated.
   
  Currently, the server is responsing in the following way: 1) upon receiving a request for object A, it constructs and sends a resposne header with status code 200 (of course no content-length specified) if the object is valid; 2) generates and buffers contents and sends buffered contents by HTTP chunk transfering.
   
  The problem here is how to handle potential errors during contents generation in the server. Since a 200 response has already been sent, I cannot send another response with another status code.
   
  I can (i) close the connection but the clients (e.g., IE) will just end as the entire data have been received. (2) send nothing and wish clients will timeout themselves. But it seems dangurous that there are chances some clients will be hanging there for a very long time.
   
  I am wondering what the "standard" way the server is expected to behavior under such situation. Any comments are welcomed and appreciated!

       
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