Tony Lea ・ Sep 27th, 2012 ・ Views
Table of Contents
- How do I monitor PHP memory usage?
- How much memory does each PHP
process consume?
- How do I check my memory usage?
- Which of the following PHP functions can be used to get the current memory usage?
So, a couple weeks
ago I experienced heavy server overloads on an app due to so many concurrent users. There may have also been some code clean up that was necessary. Either way it was kind of a headache, but also a learning experience. So upon searching the interent I could not find an easy way to print out the Server Memory Usage or CPU Usage as a percentage. So, with the help of some string manipulation and a fellow co-worker we created these 2 php functions. These configurations worked on a MediaTemple (ve)
server with Ubuntu 11.04. The first function will return the Server Memory Usage:
function get_server_memory_usage(){
$free = shell_exec('free');
$free = (string)trim($free);
$free_arr = explode("\n", $free);
$mem = explode(" ", $free_arr[1]);
$mem = array_filter($mem);
$mem = array_merge($mem);
$memory_usage = $mem[2]/$mem[1]*100;
return $memory_usage;
}
This function will return the Server CPU Usage:
function get_server_cpu_usage(){
$load = sys_getloadavg();
return $load[0];
}
So, if you were to call the two functions in a php file like this:
Server Memory Usage: = get_server_memory_usage() ?>%
Server CPU Usage: = get_server_cpu_usage() ?>%
You'll probably end up with a page that looks similar:
And that's how you can get the server memory
and cpu usage from PHP. I hope that these function can help someone else along the way.
Functions to get current CPU load and memory usage under Windows and Linux.
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| https://www.php.net/manual/en/function.sys-getloadavg.php#118673
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| Function to get current CPU load as percentage value under Windows and Linux.
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| 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).
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| header("Content-Type: text/plain");
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| function _getServerLoadLinuxData()
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| {
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| if (is_readable("/proc/stat"))
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| {
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| $stats = @file_get_contents("/proc/stat");
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| if ($stats !== false)
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| {
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| // Remove double spaces to make it easier to extract values with explode()
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| $stats = preg_replace("/[[:blank:]]+/", "", $stats);
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| // Separate lines
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| $stats = str_replace(array("\r\n", "\n\r", "\r"), "\n", $stats);
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| $stats = explode("\n", $stats);
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| // Separate values and find line for main CPU load
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| foreach ($stats as $statLine)
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| {
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| $statLineData = explode("", trim($statLine));
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| // Found!
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| if
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| (
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| (count($statLineData) >= 5) &&
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| ($statLineData[0] == "cpu")
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| )
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| {
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| return array(
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| $statLineData[1],
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| $statLineData[2],
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| $statLineData[3],
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| $statLineData[4],
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| );
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| }
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| }
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| }
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| }
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| return null;
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| }
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| // Returns server load in percent (just number, without percent sign)
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| function getServerLoad()
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| {
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| $load = null;
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| if (stristr(PHP_OS, "win"))
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| {
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| $cmd = "wmic cpu get loadpercentage /all";
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| @exec($cmd, $output);
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| if ($output)
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| {
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| foreach ($output as $line)
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| {
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| if ($line && preg_match("/^[0-9]+\$/", $line))
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| {
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| $load = $line;
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| break;
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| }
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| }
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| }
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| }
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| else
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| {
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| if (is_readable("/proc/stat"))
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| {
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| // Collect 2 samples - each with 1 second period
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| // See: https://de.wikipedia.org/wiki/Load#Der_Load_Average_auf_Unix-Systemen
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| $statData1 = _getServerLoadLinuxData();
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| sleep(1);
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| $statData2 = _getServerLoadLinuxData();
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| if
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| (
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| (!is_null($statData1)) &&
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| (!is_null($statData2))
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| )
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| {
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| // Get difference
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| $statData2[0] -= $statData1[0];
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| $statData2[1] -= $statData1[1];
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| $statData2[2] -= $statData1[2];
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| $statData2[3] -= $statData1[3];
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| // Sum up the 4 values for User, Nice, System and Idle and calculate
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| // the percentage of idle time (which is part of the 4 values!)
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| $cpuTime = $statData2[0] + $statData2[1] + $statData2[2] + $statData2[3];
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| // Invert percentage to get CPU time, not idle time
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| $load = 100 - ($statData2[3] * 100 / $cpuTime);
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| }
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| }
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| }
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| return $load;
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| }
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| //----------------------------
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| $cpuLoad = getServerLoad();
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| if (is_null($cpuLoad)) {
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| echo "CPU load not estimateable (maybe too old Windows or missing rights at Linux or Windows)";
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| }
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| else {
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| echo $cpuLoad . "%";
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| }
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| ?>
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| memory_get_usage() is used to retrieve the memory allocated to PHP only (or your running script). But intuitively, many people expect to get the memory usage of the system, based on the name of the function.
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| So if you need the overall memory usage, following function might be helpful. If retrieves the memory usage either in percent (without the percent sign) or in bytes by returning an array with free and overall memory of your system. Tested with Windows (7) and Linux (on an Raspberry Pi 2):
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| // Returns used memory (either in percent (without percent sign) or free and overall in bytes)
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| function getServerMemoryUsage($getPercentage=true)
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| {
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| $memoryTotal = null;
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| $memoryFree = null;
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| if (stristr(PHP_OS, "win")) {
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| // Get total physical memory (this is in bytes)
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| $cmd = "wmic ComputerSystem get TotalPhysicalMemory";
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| @exec($cmd, $outputTotalPhysicalMemory);
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| // Get free physical memory (this is in kibibytes!)
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| $cmd = "wmic OS get FreePhysicalMemory";
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| @exec($cmd, $outputFreePhysicalMemory);
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| if ($outputTotalPhysicalMemory && $outputFreePhysicalMemory) {
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| // Find total value
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| foreach ($outputTotalPhysicalMemory as $line) {
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| if ($line && preg_match("/^[0-9]+\$/", $line)) {
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| $memoryTotal = $line;
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| break;
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| }
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| }
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| // Find free value
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| foreach ($outputFreePhysicalMemory as $line) {
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| if ($line && preg_match("/^[0-9]+\$/", $line)) {
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| $memoryFree = $line;
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| $memoryFree *= 1024; // convert from kibibytes to bytes
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| break;
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| }
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| }
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| }
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| }
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| else
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| {
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| if (is_readable("/proc/meminfo"))
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| {
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| $stats = @file_get_contents("/proc/meminfo");
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| if ($stats !== false) {
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| // Separate lines
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| $stats = str_replace(array("\r\n", "\n\r", "\r"), "\n", $stats);
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| $stats = explode("\n", $stats);
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| // Separate values and find correct lines for total and free mem
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| foreach ($stats as $statLine) {
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| $statLineData = explode(":", trim($statLine));
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| //
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| // Extract size (TODO: It seems that (at least) the two values for total and free memory have the unit "kB" always. Is this correct?
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| //
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| // Total memory
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| if (count($statLineData) == 2 && trim($statLineData[0]) == "MemTotal") {
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| $memoryTotal = trim($statLineData[1]);
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| $memoryTotal = explode("", $memoryTotal);
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| $memoryTotal = $memoryTotal[0];
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| $memoryTotal *= 1024; // convert from kibibytes to bytes
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| }
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| // Free memory
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| if (count($statLineData) == 2 && trim($statLineData[0]) == "MemFree") {
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| $memoryFree = trim($statLineData[1]);
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| $memoryFree = explode("", $memoryFree);
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| $memoryFree = $memoryFree[0];
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| $memoryFree *= 1024; // convert from kibibytes to bytes
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| }
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| }
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| }
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| }
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| }
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| if (is_null($memoryTotal) || is_null($memoryFree)) {
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| return null;
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| } else {
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| if ($getPercentage) {
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| return (100 - ($memoryFree * 100 / $memoryTotal));
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| } else {
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| return array(
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| "total" => $memoryTotal,
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| "free" => $memoryFree,
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| );
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| }
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| }
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| }
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| function getNiceFileSize($bytes, $binaryPrefix=true) {
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| if ($binaryPrefix) {
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| $unit=array('B','KiB','MiB','GiB','TiB','PiB');
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| if ($bytes==0) return '0 ' . $unit[0];
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| return @round($bytes/pow(1024,($i=floor(log($bytes,1024)))),2) .' '. (isset($unit[$i]) ? $unit[$i] : 'B');
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| } else {
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| $unit=array('B','KB','MB','GB','TB','PB');
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| if ($bytes==0) return '0 ' . $unit[0];
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| return @round($bytes/pow(1000,($i=floor(log($bytes,1000)))),2) .' '. (isset($unit[$i]) ? $unit[$i] : 'B');
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| }
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| }
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| // Memory usage: 4.55 GiB / 23.91 GiB (19.013557664178%)
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| $memUsage = getServerMemoryUsage(false);
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| echo sprintf("Memory usage: %s / %s (%s%%)",
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| getNiceFileSize($memUsage["total"] - $memUsage["free"]),
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| getNiceFileSize($memUsage["total"]),
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| getServerMemoryUsage(true)
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| );
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| ?>
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| The function getNiceFileSize() is not required. Just used to shorten size in bytes.
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| Note: If you need the server load (CPU usage), I wrote a nice function to get that too: http://php.net/manual/en/function.sys-getloadavg.php#118673
|
How do I monitor PHP memory usage?
To check memory usage, PHP provides an inbuilt function memory_get_usage(). This function returns the amount of memory allocated to a PHP script. ** memory_get_usage() function returns the amount of memory allocated to your PHP script in bytes.
How much memory does each PHP process consume?
A typical appropriate
memory limit for PHP running Drupal is 128MB per process; for sites with a lot of contributed modules or with high-memory pages, 256MB or even 512MB may be more appropriate. It's often the case that the admin section of a site, or a particular page, uses much more memory than other pages.
How do I check my memory usage?
Press Ctrl + Shift + Esc to launch Task Manager. Or, right-click the Taskbar and select Task Manager.
Select the Performance tab and click Memory in the left panel. The Memory window lets you see your current RAM usage, check RAM speed, and view other memory hardware specifications.
Which of the following PHP functions can be used to get the current memory usage?
Which of the following PHP functions can be used to get the current memory usage? Explanation:
memory_get_usage() returns the amount of memory, in bytes, that's currently being allocated to the PHP script.
