sys_getloadavg

(PHP 5 >= 5.1.3)

sys_getloadavg — 获取系统的负载（load average）

说明

array sys_getloadavg ( void )

返回三个系统负载（系统运行队列中的进程数）的样本数据，分别是1分钟、5分钟和15分钟之前。

返回值

返回一个包含1分钟、5分钟和15分钟之前采样数据的 array 。

范例

Example #1 sys_getloadavg() 的例子

  <?php
$load  =  sys_getloadavg ();
if ( $load [ 0 ] >  80 ) {
     header ( 'HTTP/1.1 503 Too busy, try again later' );
    die( 'Server too busy. Please try again later.' );
}
 ?>

注释

Note: 此函数未在 Windows 平台下实现。

用户评论:

[#1] kexianbin at diyism dot com [2014-05-28 10:35:34]

Use this:
<?php $loads=sys_getloadavg(); $core_nums=trim(shell_exec("grep -P '^physical id' /proc/cpuinfo|wc -l")); $load=$loads[0]/$core_nums; echo $load; ?>

[#2] vladvarna at gmail dot com [2012-07-18 14:51:49]

You can emulate loadavg using this. Can also be used to get iowait

<?php function ProcStats() { $fp=fopen("/proc/stat","r"); if(false===$fp) return false; $a=explode(' ',fgets($fp)); array_shift($a); //get rid of 'cpu' while(!$a[0]) array_shift($a); //get rid of ' ' var_dump($a); fclose($fp); return $a; } $a=ProcStats(); sleep(5); $b=ProcStats(); $total=array_sum($b)-array_sum($a); $loadavg = round(100* (($b[0]+$b[1]+$b[2]) - ($a[0]+$a[1]+$a[2])) / $total, 2); // user+nice+system $iowait= round(100* ($b[4] - $a[4])/$total,2); ?>

[#3] rick at rctonline dot nl [2012-01-24 12:57:55]

Here is another one that also works on windows. Note that this method is not fast, so be careful in the number of calls to this function.

<?php function get_server_load() { if (stristr(PHP_OS, 'win')) { $wmi = new COM("Winmgmts://"); $server = $wmi->execquery("SELECT LoadPercentage FROM Win32_Processor"); $cpu_num = 0; $load_total = 0; foreach($server as $cpu){ $cpu_num++; $load_total += $cpu->loadpercentage; } $load = round($load_total/$cpu_num); } else { $sys_load = sys_getloadavg(); $load = $sys_load[0]; } return (int) $load; } ?>

[#4] 828586 at gmail dot com [2010-06-12 07:43:23]

equivalent for windows
<?php ob_start(); passthru('typeperf -sc 1 "\processor(_total)\% processor time"',$status); $content = ob_get_contents(); ob_end_clean(); if ($status === 0) { if (preg_match("/\,\"([0-9]+\.[0-9]+)\"/",$content,$load)) { if ($load[1] > get_config('busy_error')) { header('HTTP/1.1 503 Too busy, try again later'); die('Server too busy. Please try again later.'); } } } ?>

[#5] Anonymous [2009-11-19 12:14:32]

To get just current load avg, you can do :

<?php $output = shell_exec('cat /proc/loadavg'); $loadavg = substr($output,0,strpos($output," ")); ?>

[#6] scott at corelevel dot com [2006-11-27 14:47:46]

I was having a problem with a large script I need to run - was a loop through about 50,000 records and downloading several pictures for a bunch of them, and updating the database.

the problem came as I started getting visitors to my site, the server would get behind, run out of memory, iowait skyrockets, mysql slows down... was a total downhill spiral.

Use this to fix it.

$load = sys_getloadavg();
$sleep=5;
$maxload=2;
if ($load[0] > $maxload) {
sleep($sleep);
echo "Busy server - sleep $sleep seconds<br>";
}

I have to play with the load and the sleep number to find what worked for my script, but now my server does not bog at all.

[#7] surfchen at gmail dot com [2006-07-06 09:22:18]

the codes below will provide this function for order versions of PHP.
if (!function_exists('sys_getloadavg')) {
function sys_getloadavg()
{
$loadavg_file = '/proc/loadavg';
if (file_exists($loadavg_file)) {
return explode(chr(32),file_get_contents($loadavg_file));
}
return array(0,0,0);
}
}

[#8] tom pittlik [2006-03-03 02:36:21]

The code below mimics the output of sys_getloadavg(). You may have to tweak the way the substring is captured for different distros.

<?php function sys_getloadavg_hack() { $str = substr(strrchr(shell_exec("uptime"),":"),1); $avs = array_map("trim",explode(",",$str)); return $avs; } print_r(sys_getloadavg_hack()); // Array // ( // [0] => 6.24 // [1] => 4.92 // [2] => 3.99 // ) ?>

This function is a neat way of running low priority or non-essential cron jobs on a busy server - if the load is high, don't continue with the task (and try again in a few minutes time).