aws实例部署flask报错script-timed-out-before-returning-headers-application-py

来源：http://www.aisir.cn/2017/07/15/aws实例部署flask报错script-timed-out-before-returning-headers-application-py/

[Thu Jul 13 13:21:32.542375 2017] [core:error] [pid 25744] [client 127.0.0.1:48852] Script timed out before returning headers: application.py
[Thu Jul 13 13:21:32.618324 2017] [core:error] [pid 25672] [client 127.0.0.1:48754] Script timed out before returning headers: application.py
[Thu Jul 13 13:21:33.517055 2017] [core:error] [pid 25702] [client 127.0.0.1:48846] Script timed out before returning headers: application.py
[Thu Jul 13 13:21:33.593206 2017] [core:error] [pid 25722] [client 127.0.0.1:48814] Script timed out before returning headers: application.py

这是一个被困扰需求的问题，接收SQS发来的消息总量有一万多条，并不是很多，一直以来是以为flask框架的问题，所以解决方法一直是

产生的背景：

抓取Facebook广告数据并通过aws的SQS分发处理，SQS数量在万级，同时提取广告数据中的图片视频信息，执行时间多消耗在网络请求。

问题解决：

配置机器实例

可见性超时（SQS visibility timeout）：3600

官方解释：在将入站消息返回队列之前将其锁定以供处理的秒数。明白的说就是大于应用处理SQS消息的时间设置

不活动超时（inactivity timeout）:1800 

官方解释 ：在现有连接上等待来自应用程序的响应的秒数。即等多久就报time out错误，也就是上面看到的报错。

注意：不活动超时需要小于可见性超时，否则报错  The inactivity timeout you specified for your worker tier environment is greater than the SQS visibility timeout. Be aware that this can result in multiple retries, which can increase the resources your application tasks consume. Consider an inactivity timeout that is not greater than 300.

Stack Overflow上对于该问题的解决方式是，在.ebextensions中命令，测试无效

:files:
"/etc/httpd/conf.d/wsgi_custom.conf":
mode: "000644"
owner: root
group: root
content: |
WSGIApplicationGroup %{GLOBAL}