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POHeroku truncates HTTP responses?
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  1. POHeroku truncates HTTP responses?
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    copied!<p>I am running a <strong>Flask/Gunicorn</strong> Python app on a Heroku Cedar dyno. The app returns <code>JSON responses</code> to its clients (it's an <code>API server</code>, really).</p> <p>Once in a while clients get 0-byte responses. It's not me returning them, however. Here is a snippet of my app's log:</p> <blockquote> <p>Mar 14 13:13:31 d.0b1adf0a-0597-4f5c-8901-dfe7cda9bce0 app[web.1] [2013-03-14 13:13:31 UTC] 10.104.41.136 apisrv - api_get_credits_balance(): session_token=[MASKED]</p> </blockquote> <p>The first line above is me starting to handle the request. </p> <blockquote> <p>Mar 14 13:13:31 d.0b1adf0a-0597-4f5c-8901-dfe7cda9bce0 app[web.1] [2013-03-14 13:13:31 UTC] 10.104.41.136 apisrv 1252148511 api_get_credits_balance(): returning [{'credits_balance': 0}]</p> </blockquote> <p>The second line is me returning a value (to Flask -- it's a Flask "Response" object).</p> <blockquote> <p>Mar 14 13:13:31 d.0b1adf0a-0597-4f5c-8901-dfe7cda9bce0 app[web.1] "10.104.41.136 - - [14/Mar/2013:13:13:31] "POST /get_credits_balance?session_token=MASKED HTTP/1.1" 200 22 "-" "Appcelerator Titanium/3.0.0.GA (iPhone/6.1.2; iPhone OS; en_US;)"</p> </blockquote> <p>The third line is Gnicorn's, where you can see the Gunicorn got the 200 status and 22 bytes HTTP body ("<code>200 22</code>").</p> <p>However, the client got 0 bytes. Here is the Heroku router log:</p> <blockquote> <p>Mar 14 13:13:30 d.0b1adf0a-0597-4f5c-8901-dfe7cda9bce0 heroku[router] at=info method=POST path=/get_credits_balance?session_token=MASKED host=matchspot-apisrv.herokuapp.com fwd="66.87.116.128" dyno=web.1 queue=0 wait=0ms connect=1ms service=19ms status=200 bytes=0</p> </blockquote> <p>Why does Gunicorn return 22 bytes, but Heroku sees 0, and indeed passes back 0 bytes to the client? Is this a Heroku bug?</p>
 

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