Major Description
Caching proxy running ATS 5.3.x (5.3.0, 5.3.1, 5.3.2 all fail) with proxy.config.http.cache.when_to_revalidate = 4 breaks akamaihd.net live streaming.
The actual problem is that ATS rewrites origin response from 200 to 304, due to If-Modified-Since conditional header in client's request. As per ATS logic object is unmodified, but in fact it is. Most probably player and server somehow play with if-modified-since/last-modified headers pair to communicate position in the live stream. What is obvious is that Last-Modified = If-Modified-Since.
As result, Akamai player keeps repeating the said request, expecting it's 200, but getting 304 thus live video freezes forever, just a few seconds after start.
IMHO when proxy.config.http.cache.when_to_revalidate = 4, ATS shall not interfere with origin response in this manner.
Here's a debug log of request and response headers at different states in a single transaction:
+++++++++ Incoming Request +++++++++ -- State Machine Id: 168 GET http:///z/delayed/indvsa2015_INDVSSATEST1DAY1_1@336263/464_209823ecd2922291-p.bootstrap?g=YCEAMIWDQZQT&hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8&hdcore=3.7.0&plugin=aasp-3.7.0.39.44 HTTP/1.1 Host: sshds5-lh.akamaihd.net Connection: keep-alive User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36 X-Requested-With: ShockwaveFlash/19.0.0.226 Accept: */* DNT: 1 Referer: http://www.hotstar.com/ Accept-Encoding: gzip Accept-Language: en-US,en;q=0.8,bg;q=0.6 Cookie: _alid_=PmjLqgcUUqw6TP5gtK/xbg==; hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8 If-Modified-Since: Thu, 05 Nov 2015 02:30:28 GMT +++++++++ Proxy's Request +++++++++ -- State Machine Id: 168 GET /z/delayed/indvsa2015_INDVSSATEST1DAY1_1@336263/464_209823ecd2922291-p.bootstrap?g=YCEAMIWDQZQT&hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8&hdcore=3.7.0&plugin=aasp-3.7.0.39.44 HTTP/1.1 Host: sshds5-lh.akamaihd.net User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36 X-Requested-With: ShockwaveFlash/19.0.0.226 Accept: */* DNT: 1 Referer: http://www.hotstar.com/ Accept-Encoding: gzip Accept-Language: en-US,en;q=0.8,bg;q=0.6 Cookie: _alid_=PmjLqgcUUqw6TP5gtK/xbg==; hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8 If-Modified-Since: Thu, 05 Nov 2015 02:30:28 GMT +++++++++ Proxy's Request after hooks +++++++++ -- State Machine Id: 168 GET /z/delayed/indvsa2015_INDVSSATEST1DAY1_1@336263/464_209823ecd2922291-p.bootstrap?g=YCEAMIWDQZQT&hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8&hdcore=3.7.0&plugin=aasp-3.7.0.39.44 HTTP/1.1 Host: sshds5-lh.akamaihd.net User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36 X-Requested-With: ShockwaveFlash/19.0.0.226 Accept: */* DNT: 1 Referer: http://www.hotstar.com/ Accept-Encoding: gzip Accept-Language: en-US,en;q=0.8,bg;q=0.6 Cookie: _alid_=PmjLqgcUUqw6TP5gtK/xbg==; hdntl=exp=1446809835~acl=%2f*~data=hdntl~hmac=ebaedb13781605ce7f9f26b84e1346a7d43ecf0dfcc99e6b53e32487565ba3f8 If-Modified-Since: Thu, 05 Nov 2015 02:30:28 GMT +++++++++ Incoming O.S. Response +++++++++ -- State Machine Id: 168 HTTP/1.1 200 OK Server: AkamaiGHost Mime-Version: 1.0 Content-Type: video/abst Content-Length: 122 Last-Modified: Thu, 05 Nov 2015 02:30:28 GMT Expires: Thu, 05 Nov 2015 11:38:01 GMT Cache-Control: max-age=0, no-cache Pragma: no-cache Date: Thu, 05 Nov 2015 11:38:01 GMT Connection: keep-alive Set-Cookie: _alid_=PmjLqgcUUqw6TP5gtK/xbg==; path=/z/delayed/indvsa2015_INDVSSATEST1DAY1_1@336263/; domain=sshds5-lh.akamaihd.net +++++++++ Base Header for Building Response +++++++++ -- State Machine Id: 168 HTTP/1.1 200 OK Server: AkamaiGHost Mime-Version: 1.0 Content-Type: video/abst Content-Length: 122 Last-Modified: Thu, 05 Nov 2015 02:30:28 GMT Expires: Thu, 05 Nov 2015 11:38:01 GMT Cache-Control: max-age=0, no-cache Pragma: no-cache Date: Thu, 05 Nov 2015 11:38:01 GMT Connection: keep-alive Set-Cookie: _alid_=PmjLqgcUUqw6TP5gtK/xbg==; path=/z/delayed/indvsa2015_INDVSSATEST1DAY1_1@336263/; domain=sshds5-lh.akamaihd.net +++++++++ Proxy's Response 2 +++++++++ -- State Machine Id: 168 HTTP/1.1 304 Not Modified Date: Thu, 05 Nov 2015 11:38:01 GMT Expires: Thu, 05 Nov 2015 11:38:01 GMT Cache-Control: max-age=0, no-cache Connection: keep-alive +++++++++ Proxy's Response (Client Conditionals) +++++++++ -- State Machine Id: 168 HTTP/1.1 304 Not Modified Date: Thu, 05 Nov 2015 11:38:01 GMT Expires: Thu, 05 Nov 2015 11:38:01 GMT Cache-Control: max-age=0, no-cache Connection: keep-alive