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I am sending an ajax HEAD request to a file served over CloudFront. The max-age set for this file in S3 is 1800. Always it miss the cache in CloudFront.

Is this the expected behavior? Or is there anything has to be configured so that the HEAD request hits cloudfront until the specified time in max-age?

EDIT

Two consecutive head request/response are as below:

Request 1

Request URL:https://360-dev.web-dev.mydomain.com/resources/data/master.json
Request Method:HEAD
Status Code:304 Not Modified
Remote Address:52.84.105.65:443

Response Headers
view source
Cache-Control:max-age=1800, private
Connection:keep-alive
Date:Tue, 27 Sep 2016 10:20:56 GMT
ETag:"213cd6a833efde3409a8dc3808e01c46"
Last-Modified:Thu, 22 Sep 2016 11:35:17 GMT
Server:AmazonS3
Via:1.1 f2eee4ce6eb32d1b7578af7dc2c917de.cloudfront.net (CloudFront)
X-Amz-Cf-Id:QgmjSCu2uIam9Jmo63a8g-qytd6OsyalTEpNUGOaMp0EtJkheENkIA==
x-amz-storage-class:REDUCED_REDUNDANCY
X-Cache:Miss from cloudfront

Request Headers
view source
Accept:*/*
Accept-Encoding:gzip, deflate, sdch, br
Accept-Language:en-US,en;q=0.8
Cache-Control:max-age=0
Connection:keep-alive
Content-Type:application/x-www-form-urlencoded
Cookie:UnicaID=gU6xZpJesOr-Z6LqaYt; __utma=227427714.2013234852.1473314245.1473314245.1473314245.1; __utmz=227427714.1473314245.1.1.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not%20provided); SMIDENTITY=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; SMSESSION=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; CloudFront-Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly8zNjAtZGV2Ki53ZWItZGV2LmJtcy5jb20vKiIsIkNvbmRpdGlvbiI6eyJEYXRlTGVzc1RoYW4iOnsiQVdTOkVwb2NoVGltZSI6MTQ3NTAwNjQ2OX19fV19; CloudFront-Signature=SvN~2tPgK~N~GzoY2pVOFZN1nic4t2Kgq3AucGD8gvuGS4iqjnlBIceFM~k5ZHZRlSbWa8V8QZzoYuMZvY2GvAjGJrDigJD93Vxq0qCm6alexx5~yxtX1FebaFAp68fgqo1tbjVYm7nCYrvGl2RebFcucbN6RC-Lo6aBvPnIgTrXqa6OrJKgxQQxii~LE7l9XnnKHWoYnrjBZEFWuqJ5fHrWK1MennKKAh67nOO9OGznX9slQRXBGCpNV4SCICzQEMaMxHBANjVE7nTfP9YussBV-AXYaQdkvdNt6LWcDotZu~wDDqlrBpNcru6EqJackyUAOvS982t4BPGAiL1jjQ__; CloudFront-Key-Pair-Id=APKAIOWOUVDQ5VOOZ5IA; Custom-Insite-Cookie=eyJMREFQR3JvdXAiOlsiIl0sInVzZXJOYW1lIjoic3VicmFtbTIiLCJpbnRlcm5ldCI6dHJ1ZSwiZW52aXJvbm1lbnQiOiIzNjAtZGV2IiwibG9naW5EYXRlIjoiMjAxNi0wOS0yN1QxMDowMTowOS4zODhaIn0%3D; rtFa=fa1/uY2RI0bciZ9ZZSoGEQfpjl1ezr5wmPN7/U+ySlNuu2iSn1blhq9qeQBW2Iq3gSllMAAlV5troHg6UfB2KKR7TkNU5Q3IS3TnYS+XJJxSaLXv5ghig7fDjU1KKCs9IbrJaCW9XIMzgtfDlxXE/EHRhD3+u5xX4KegxZwGjWMMNM0QOOZrtMvk98h08BhpKfAChj8CPmeaghOehRhgxbOlLwQ+1AHIgrZ4Y8n7sbW4zw4NnAPhTgdtfJ43midH1pfqIH5ijy5x4a+61nczQFkI9+WxMfqsBVJDDteeBLVc+NPuWw84JRlar01jB4Qpm0VFzt8sXMOApfNosrsgR1iQmlcdZqSpMcrKIEwKw11GZiyNGyVzMd3R1/vzQI9gIAAAAA==
Host:360-dev.web-dev.mydomain.com
If-Modified-Since:Thu, 22 Sep 2016 11:35:17 GMT
If-None-Match:"213cd6a833efde3409a8dc3808e01c46"
Referer:https://360-dev.web-dev.mydomain.com/home.html
User-Agent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36
X-Requested-With:XMLHttpRequest

Request 2

Request URL:https://360-dev.web-dev.mydomain.com/resources/data/master.json
Request Method:HEAD
Status Code:304 Not Modified
Remote Address:52.84.105.65:443

Response Headers
view source
Cache-Control:max-age=1800, private
Connection:keep-alive
Date:Tue, 27 Sep 2016 10:22:09 GMT
ETag:"213cd6a833efde3409a8dc3808e01c46"
Last-Modified:Thu, 22 Sep 2016 11:35:17 GMT
Server:AmazonS3
Via:1.1 0f99540d655ae57ac39033aac52161f5.cloudfront.net (CloudFront)
X-Amz-Cf-Id:3ci8nzrDmmcJMq7_ElxxU6HPbedPqp0P1fDXiDUFIO7b-qm_R2bxMg==
x-amz-storage-class:REDUCED_REDUNDANCY
X-Cache:Miss from cloudfront

Request Headers
view source
Accept:*/*
Accept-Encoding:gzip, deflate, sdch, br
Accept-Language:en-US,en;q=0.8
Cache-Control:max-age=0
Connection:keep-alive
Content-Type:application/x-www-form-urlencoded
Cookie:UnicaID=gU6xZpJesOr-Z6LqaYt; __utma=227427714.2013234852.1473314245.1473314245.1473314245.1; __utmz=227427714.1473314245.1.1.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not%20provided); SMIDENTITY=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; SMSESSION=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; CloudFront-Policy=eyJTdGF0ZW1lbnQiOlt7IlJlc291cmNlIjoiaHR0cHM6Ly8zNjAtZGV2Ki53ZWItZGV2LmJtcy5jb20vKiIsIkNvbmRpdGlvbiI6eyJEYXRlTGVzc1RoYW4iOnsiQVdTOkVwb2NoVGltZSI6MTQ3NTAwNjQ2OX19fV19; CloudFront-Signature=SvN~2tPgK~N~GzoY2pVOFZN1nic4t2Kgq3AucGD8gvuGS4iqjnlBIceFM~k5ZHZRlSbWa8V8QZzoYuMZvY2GvAjGJrDigJD93Vxq0qCm6alexx5~yxtX1FebaFAp68fgqo1tbjVYm7nCYrvGl2RebFcucbN6RC-Lo6aBvPnIgTrXqa6OrJKgxQQxii~LE7l9XnnKHWoYnrjBZEFWuqJ5fHrWK1MennKKAh67nOO9OGznX9slQRXBGCpNV4SCICzQEMaMxHBANjVE7nTfP9YussBV-AXYaQdkvdNt6LWcDotZu~wDDqlrBpNcru6EqJackyUAOvS982t4BPGAiL1jjQ__; CloudFront-Key-Pair-Id=APKAIOWOUVDQ5VOOZ5IA; Custom-Insite-Cookie=eyJMREFQR3JvdXAiOlsiIl0sInVzZXJOYW1lIjoic3VicmFtbTIiLCJpbnRlcm5ldCI6dHJ1ZSwiZW52aXJvbm1lbnQiOiIzNjAtZGV2IiwibG9naW5EYXRlIjoiMjAxNi0wOS0yN1QxMDowMTowOS4zODhaIn0%3D; rtFa=fa1/uY2RI0bciZ9ZZSoGEQfpjl1ezr5wmPN7/U+ySlNuu2iSn1blhq9qeQBW2Iq3gSllMAAlV5troHg6UfB2KKR7TkNU5Q3IS3TnYS+XJJxSaLXv5ghig7fDjU1KKCs9IbrJaCW9XIMzgtfDlxXE/EHRhD3+u5xX4KegxZwGjWMMNM0QOOZrtMvk98h08BhpKfAChj8CPmeaghOehRhgxbOlLwQ+1AHIgrZ4Y8n7sbW4zw4NnAPhTgdtfJ43midH1pfqIH5ijy5x4a+61nczQFkI9+WxMfqsBVJDDteeBLVc+NPuWw84JRlar01jB4Qpm0VFzt8sXMOApfNosrsgR1iQmlcdZqSpMcrKIEwKw11GZiyNGyVzMd3R1/vzQI9gIAAAAA==
Host:360-dev.web-dev.mydomain.com
If-Modified-Since:Thu, 22 Sep 2016 11:35:17 GMT
If-None-Match:"213cd6a833efde3409a8dc3808e01c46"
Referer:https://360-dev.web-dev.mydomain.com/home.html
User-Agent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36
X-Requested-With:XMLHttpRequest
Cœur
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Manu
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  • **"always"**? Or more often than expected? Can you provide an example URL that has this behavior? Does the same object serve from the cache on a `GET` request? – Michael - sqlbot Sep 26 '16 at 12:34
  • Yes. I have never seen the HEAD request come from cache and it is always taking more than 1 second. As this is an internal application with two level of authentication, sorry I am not able to share the URL. Yes the same objects are served from cache on GET request and will take less than 10 ms only – Manu Sep 27 '16 at 04:13
  • In that case, can you capture the request and response headers of two consecutive requests for the `HEAD` of the same object from the same client and post those? Also mentiom what's on the back-end (S3 or custom origin, what platform, etc.). – Michael - sqlbot Sep 27 '16 at 10:00
  • Added the request/response above. (Modified the domain name). The max-age=1800 and the backend is S3. – Manu Sep 27 '16 at 10:37

1 Answers1

3

See the below image of a 'behaviour' for reference:

enter image description here

Things to note:

  1. Behaviours work off 'path patterns' in the priority order that they are defined, make sure you open the correct behaviour to see how its configured.
  2. Default TTL will come into play if your server does NOT send cache headers such as "Cache-Control max-age, Cache-Control s-maxage, and Expires to objects".
  3. Min & max interact with the HTTP headers sent and do what their names suggest.
  4. If in head requests you have different headers, all the headers will become part of the key which cloud front will use to cache it, and compare that key with the new requests to determine whether its the same or not as the previous name.
  5. If cookies are being different, most notably authentication & session keys (and any other) and if forward cookies option is not set to "None" it will use the cookie values as part of the key as well (this will most likely cause your cache to be seldom used). 6) Query strings forwarding if used, will also cause it to become part of the key.

Now you can either determine it from this info or if you can't then paste a screenshot of your behaviour screen, after making sure its the correct behaviour, and I can help further.

Sumit Maingi
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