请求不等待 PHP 漫长的过程，返回 503 服务不可用

Question

我想通过使用 PHP 的 ini_set 函数来测试 max_execution_time 设置。所以我设置了一个简单的测试来创建一个无限循环以确保它会超时。

这是我的代码

Test.php
<?php         
   ini_set('max_execution_time', 300);
   echo "Hello World";
   //for(;;); Commented, see history
   sleep(100);

?>

这段代码在我运行在 XAMPP 上的 Windows 机器上运行良好。 5 分钟后，会显示 Hello World 和致命错误超出超时。

然后我将代码移至运行 ubuntu 和 Apache 的 VPS。然后我从浏览器打开网页。但是，仅 1 分钟后，我的浏览器显示

Error Code: 503 Service Unavailable
Network Error 
A communication error occurred: "Operation timed out"
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.

它甚至不等待 5 分钟。并且在 1 分钟后一直出错。但是在我的错误日志中，Apache 在 5 分钟后写入了超过 time 的致命错误。

所以，在我看来，请求在 PHP 脚本实际完成之前就被取消了。

我在 apache2.conf 上使用默认设置和额外的虚拟主机

apache2.conf (additional only)
<Directory /var/www/mysite.com/public>
    Options FollowSymLinks
    AllowOverride All
</Directory>

mysite.virtualhost.conf

<VirtualHost virtualhost.mysite.com:80>
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    ServerAdmin admin@mysite.com
    ServerName virtualhost.mysite.com
    ServerAlias virtualhost.mysite.com
    DocumentRoot /var/www/mysite.com/public

    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

php.ini 文件

Php.ini
safe_mode = off
max_execution_time = 1200

那么，我在这里错过了什么配置？我认为我的 apache 配置有问题，但我不知道是哪一部分。

更新

查看进程运行后，运行无限循环的 apache 进程正在消耗 99% 的 CPU。为什么会这样？使用 strace 查看返回 this 的进程

write(10, "36.72.135.58 - - [22/Jul/2016:03:15:35 +0700] \"GET /test11.php HTTP/1.1\" 500 211 \"-\" \"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36\"\n", 198) = 198
times({tms_utime=29996, tms_stime=4, tms_cutime=0, tms_cstime=0}) = 4967918020
gettimeofday({1469132442, 496002}, NULL) = 0
gettimeofday({1469132442, 496046}, NULL) = 0
shutdown(17, SHUT_WR)                   = 0
poll([{fd=17, events=POLLIN}], 1, 2000) = 1 ([{fd=17, revents=POLLIN|POLLHUP}])
read(17, "", 512)                       = 0
close(17)                               = 0
read(5, 0x7fff82f5cf67, 1)              = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({1469132442, 496411}, NULL) = 0
accept4(4,  <detached ...>

Answer 1

我遇到了这个问题，我解决了增加清漆的 first_byte_timeout 的问题 /etc/varnish/default.vcl 默认为 60，根据您的需要更改。