时间:2021-07-01 10:21:17 帮助过:9人阅读
$ctx = stream_context_create(array(
'http' => array(
'timeout' => 1 //设置一个超时时间,单位为秒
)
)
);
file_get_contents("http://example.com/", 0, $ctx);
?>
当然,导致 php-cgi 进程 CPU 100% 的原因不只有这一种,那么,怎么确定是 file_get_contents() 函数导致的呢?
首先,使用 top 命令查看 CPU 使用率较高的 php-cgi 进程。
代码如下:
top - 10:34:18 up 724 days, 21:01, 3 users, load average: 17.86, 11.16, 7.69
Tasks: 561 total, 15 running, 546 sleeping, 0 stopped, 0 zombie
Cpu(s): 5.9%us, 4.2%sy, 0.0%ni, 89.4%id, 0.2%wa, 0.0%hi, 0.2%si, 0.0%st
Mem: 8100996k total, 4320108k used, 3780888k free, 772572k buffers
Swap: 8193108k total, 50776k used, 8142332k free, 412088k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
10747 www 18 0 360m 22m 12m R 100.6 0.3 0:02.60 php-cgi
10709 www 16 0 359m 28m 17m R 96.8 0.4 0:11.34 php-cgi
10745 www 18 0 360m 24m 14m R 94.8 0.3 0:39.51 php-cgi
10707 www 18 0 360m 25m 14m S 77.4 0.3 0:33.48 php-cgi
10782 www 20 0 360m 26m 15m R 75.5 0.3 0:10.93 php-cgi
10708 www 25 0 360m 22m 12m R 69.7 0.3 0:45.16 php-cgi
10683 www 25 0 362m 28m 15m R 54.2 0.4 0:32.65 php-cgi
10711 www 25 0 360m 25m 15m R 52.2 0.3 0:44.25 php-cgi
10688 www 25 0 359m 25m 15m R 38.7 0.3 0:10.44 php-cgi
10719 www 25 0 360m 26m 16m R 7.7 0.3 0:40.59 php-cgi
找其中一个 CPU 100% 的 php-cgi 进程的 PID,用以下命令跟踪一下:
代码如下:
strace -p 10747
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
select(7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0})
poll([{fd=6, events=POLLIN}], 1, 0) = 0 (Timeout)
那么,就可以确定是 file_get_contents() 导致的问题了。http://www.bkjia.com/PHPjc/324141.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/324141.htmlTechArticle后来,我通过跟踪发现,这类情况的出现,跟 PHP 的 file_get_contents() 函数有着密切的关系。 大、中型网站中,基于 HTTP 协议的 API 接口调用,...