sys_getloadavg
(PHP 5 >= 5.1.3)
sys_getloadavg — Gets system load average
Description
array sys_getloadavg
( void
)
Returns three samples representing the average system load (the number of processes in the system run queue) over the last 1, 5 and 15 minutes, respectively.
Return Values
Returns an array with three samples (last 1, 5 and 15 minutes).
Examples
Example #1 A sys_getloadavg() example
<?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.');
}
?>
Notes
Note: This function is not implemented on Windows platforms.
Коментарии
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).
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);
}
}
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.
To get just current load avg, you can do :
<?php
$output = shell_exec('cat /proc/loadavg');
$loadavg = substr($output,0,strpos($output," "));
?>
equivalent for windows<?php
ob_start();
passthru('typeperf -sc 1 "\processor(_total)\% processor time"',$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.');
}
}
}
?>
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;
}
?>
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);
?>
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;
?>
Function to get current CPU load as percentage value under Windows and Linux.
Note: Function is getServerLoad(). It will return a decimal value as percentage of current CPU load or NULL if something went wrong (e. g. insufficient access rights).
<?php
header("Content-Type: text/plain");
function _getServerLoadLinuxData()
{
if (is_readable("/proc/stat"))
{
$stats = @file_get_contents("/proc/stat");
if ($stats !== false)
{
// Remove double spaces to make it easier to extract values with explode()
$stats = preg_replace("/[[:blank:]]+/", " ", $stats);
// Separate lines
$stats = str_replace(array("\r\n", "\n\r", "\r"), "\n", $stats);
$stats = explode("\n", $stats);
// Separate values and find line for main CPU load
foreach ($stats as $statLine)
{
$statLineData = explode(" ", trim($statLine));
// Found!
if
(
(count($statLineData) >= 5) &&
($statLineData[0] == "cpu")
)
{
return array(
$statLineData[1],
$statLineData[2],
$statLineData[3],
$statLineData[4],
);
}
}
}
}
return null;
}
// Returns server load in percent (just number, without percent sign)
function getServerLoad()
{
$load = null;
if (stristr(PHP_OS, "win"))
{
$cmd = "wmic cpu get loadpercentage /all";
@exec($cmd, $output);
if ($output)
{
foreach ($output as $line)
{
if ($line && preg_match("/^[0-9]+\$/", $line))
{
$load = $line;
break;
}
}
}
}
else
{
if (is_readable("/proc/stat"))
{
// Collect 2 samples - each with 1 second period
// See: https://de.wikipedia.org/wiki/Load#Der_Load_Average_auf_Unix-Systemen
$statData1 = _getServerLoadLinuxData();
sleep(1);
$statData2 = _getServerLoadLinuxData();
if
(
(!is_null($statData1)) &&
(!is_null($statData2))
)
{
// Get difference
$statData2[0] -= $statData1[0];
$statData2[1] -= $statData1[1];
$statData2[2] -= $statData1[2];
$statData2[3] -= $statData1[3];
// Sum up the 4 values for User, Nice, System and Idle and calculate
// the percentage of idle time (which is part of the 4 values!)
$cpuTime = $statData2[0] + $statData2[1] + $statData2[2] + $statData2[3];
// Invert percentage to get CPU time, not idle time
$load = 100 - ($statData2[3] * 100 / $cpuTime);
}
}
}
return $load;
}
//----------------------------
$cpuLoad = getServerLoad();
if (is_null($cpuLoad)) {
echo "CPU load not estimateable (maybe too old Windows or missing rights at Linux or Windows)";
}
else {
echo $cpuLoad . "%";
}
?>
<?php // Usage processor in Windows using FFI
if(!dl("ffi")) // Load the extension
throw new Exception('Cound not load the FFI extension.');
function GetSystemTimes()
{
static $Kernel32;
$Kernel32??=FFI::cdef(<<<'IDL'
bool GetSystemTimes(long long *IdleTime, long long *KernelTime, long long *UserTime);
int GetLastError();
IDL, 'Kernel32.dll');
$IdleTime = FFI::new('long long');
$KernelTime = FFI::new('long long'); // already has idle time
$UserTime = FFI::new('long long');
if($Kernel32->GetSystemTimes(FFI::addr($IdleTime), FFI::addr($KernelTime), FFI::addr($UserTime)))
return [
'Idle' =>$IdleTime ->cdata,
'Kernel' =>$KernelTime ->cdata, // already has idle time
'User' =>$UserTime ->cdata,
];
return [];
}
function GetSystemTimesDelta()
{
static $Last=null;
static $Delta=[0,1];
$Times=GetSystemTimes();
$Last??=$Times;
$Idle =$Times['Idle' ]-$Last['Idle' ];
$All =$Times['Kernel' ]-$Last['Kernel' ]+ // Kernel already has idle time
$Times['User' ]-$Last['User' ];
if($All>1_000_000) // 100ms
{
$Delta=[$Idle, $All];
$Last=$Times;
}
return $Delta;
}
function ProcessorLoad()
{
static $Load=0;
[$Idle, $All]=GetSystemTimesDelta();
if($All>0.0)
$Load=1-$Idle/$All;
return $Load;
}
function KbHit()
{
Static $Sys;
$Sys??=FFI::cdef('bool _kbhit();', 'msvcrt.dll');
return $Sys->_kbhit();
}
while(!KbHit())
{
echo str_pad((string)round(ProcessorLoad()*100), 3, ' ', STR_PAD_LEFT), "%\n";
sleep(1);
}
?>
It is important to note that sys_getloadavg() does not return a percentage, and the numbers that it returns are completely meaningless if you do not know the number of CPU cores. To get the number as a percentage you need to divide the value by the number of CPU cores in the system. (eg: if the value is 0.5 and you have two cores, then you are using 25% of the CPU on average). Here is a simple function to get the values as a percent:
<?php
function percentloadavg(){
$cpu_count = 1;
if(is_file('/proc/cpuinfo')) {
$cpuinfo = file_get_contents('/proc/cpuinfo');
preg_match_all('/^processor/m', $cpuinfo, $matches);
$cpu_count = count($matches[0]);
}
$sys_getloadavg = sys_getloadavg();
$sys_getloadavg[0] = $sys_getloadavg[0] / $cpu_count;
$sys_getloadavg[1] = $sys_getloadavg[1] / $cpu_count;
$sys_getloadavg[2] = $sys_getloadavg[2] / $cpu_count;
return $sys_getloadavg;
}
?>
simple function to get the cpu load with availability to most os platforms because I haven't actually been able to find a similar protocol if you happen to be testing out various os platforms...
function cpu_load():?string {
$load='';
if(strtolower(PHP_OS_FAMILY)=="windows") {
exec("wmic cpu get loadpercentage /all",$out);
if($out) {
foreach($out as $line) {
if($line&&preg_match("/^[0-9]+\$/",$line)) {
$load=$line;
break;
}
}
}
} else {
$load=sys_getloadavg();
}
return $load;
}