小编Man*_*anu的帖子

我正在向通过CloudFront提供的文件发送ajax HEAD请求.在S3中为此文件设置的max-age是1800.始终错过CloudFront中的缓存.

这是预期的行为吗？或者是否需要配置任何内容以便HEAD请求在max-age中指定的时间之前到达cloudfront？

编辑

两个连续的头部请求/响应如下:

要求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 …

在php中,我们可以通过多种方式追加字符串.

            Method 1
            ----------------------------
            $sql  = "SELECT field1, ";
            $sql .= "       field2, ";
            $sql .= "       field3, ";
            $sql .= "       field4, ";
            $sql .= "FROM   table1 ";
            $sql .= "WHERE  condition1 = '".$value."' " ;

            Method 2
            ----------------------------
            $sql  = 'SELECT field1, ';
            $sql .= '       field2, ';
            $sql .= '       field3, ';
            $sql .= '       field4, ';
            $sql .= 'FROM   table1 ';
            $sql .= 'WHERE  condition1 = "'.$value.'" ' ;

            Method 3
            ----------------------------
            $sql  = 'SELECT field1, …