我使用php curl与nginx作为代理。下面是我的代码:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_PROXY, $proxy);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$curl_scraped_page = curl_exec($ch);
curl_close($ch);
echo $curl_scraped_page;

之后的一段时间，运行nginx加载非常慢，有时它返回错误500。

日志显示

failed (24: Too many open files)，

更多细节:

root@proxy-s2:~# ulimit -Hn
4096
root@proxy-s2:~# ulimit -Sn
1024

服务器上没有其他脚本在运行，也没有其他脚本在使用这个代理。

是nginx的bug吗?如何解决?

或

还能是什么呢?如何解决这个问题?

• 我没有改变nginx的默认配置
• Nginx重启解决了问题(暂时我猜)

worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;
    gzip  on;
    server {
        listen       8080;
        location / {
            resolver 8.8.8.8;
            proxy_pass http://$http_host$uri$is_args$args;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}

top - 09:23:55 up 21:51,  1 user,  load average: 0.09, 0.13, 0.08
KiB Mem:    496164 total,   444328 used,    51836 free,    12300 buffers
KiB Swap:        0 total,        0 used,        0 free.   336228 cached Mem
  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
    8 root      20   0       0      0      0 S  0.0  0.0   4:57.56 rcuos/0
 4904 nobody    20   0   97796  14128   1012 R  0.0  2.8   4:19.82 nginx
    7 root      20   0       0      0      0 S  0.0  0.0   2:11.35 rcu_sched
    3 root      20   0       0      0      0 S  0.0  0.0   0:18.50 ksoftirqd/0
  832 root      20   0  139208   6808    172 S  0.0  1.4   0:13.11 nova-agent
   45 root      20   0       0      0      0 S  0.0  0.0   0:06.21 xenbus
   74 root      20   0       0      0      0 S  0.0  0.0   0:03.03 kworker/u30:1
  155 root      20   0       0      0      0 S  0.0  0.0   0:02.73 jbd2/xvda1-8
   46 root      20   0       0      0      0 R  0.0  0.0   0:02.39 kworker/0:1
   57 root      20   0       0      0      0 S  0.0  0.0   0:01.91 kswapd0
    1 root      20   0   33448   2404   1136 S  0.0  0.5   0:01.47 init
  391 root      20   0   18048   1336    996 S  0.0  0.3   0:00.97 xe-daemon
 1034 syslog    20   0  255840   2632    784 S  0.0  0.5   0:00.90 rsyslogd
 1107 root      20   0   61364   3048   2364 S  0.0  0.6   0:00.73 sshd
   40 root      rt   0       0      0      0 S  0.0  0.0   0:00.29 watchdog/0
  316 root      20   0   19472    456    252 S  0.0  0.1   0:00.12 upstart-udev-br
    6 root      20   0       0      0      0 S  0.0  0.0   0:00.11 kworker/u30:0
 1098 root      20   0   23652   1036    784 S  0.0  0.2   0:00.08 cron
 7935 root      20   0  105632   4272   3284 S  0.0  0.9   0:00.07 sshd
  330 root      20   0   51328   1348    696 S  0.0  0.3   0:00.06 systemd-udevd
 7953 root      20   0   22548   3428   1680 S  0.0  0.7   0:00.05 bash
  678 root      20   0   15256    524    268 S  0.0  0.1   0:00.04 upstart-socket-
 8647 root      20   0   25064   1532   1076 R  0.0  0.3   0:00.03 top

mpstat

root@proxy-s2:~# mpstat
Linux 3.13.0-55-generic (proxy-s2)      07/09/2015      _x86_64_        (1 CPU)
09:22:17 AM  CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal  %guest  %gnice   %idle
09:22:17 AM  all    0.94    0.00    1.63    0.16    0.00    2.16    0.92    0.00    0.00   94.20

iostat

root@proxy-s2:~# iostat
Linux 3.13.0-55-generic (proxy-s2)      07/09/2015      _x86_64_        (1 CPU)
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.94    0.00    3.80    0.16    0.92   94.19
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
xvdc              0.01         0.02         0.00       1710          0
xvda              3.16         4.19        88.56     322833    6815612