php randomly ignores require_once - possible windows issue - php

Question

First of all I am not sure if this the correct place to post about this particular problem because I don't know what the root cause is. If it isn't the right place, please say so and close the topic.
In a Windows Server 2012 64bit environment with 32GB RAM and an intel i7-4770, recently (last 4 months - before that it never happened) errors have started to appear in php_error.log with a totally random pattern as to when.
The errors say that functions or variables defined in other files included with require_once() do not exist. Once these errors start happening a reboot of the server machine "fixes" the issue. It takes a random amount of time for the problem to appear again, from 3 days to 10 days or 4 weeks. I have made disk checks for errors but nothing has come up
example1:
[21-Apr-2018 07:36:26 Asia/Kuwait] PHP Notice: Undefined variable: APPLICATIONDIRECTORY in C:\inetpub\wwwroot\ell\makeIdent.php on line 18
[21-Apr-2018 07:36:26 Asia/Kuwait] PHP Notice: Undefined variable: DLLDIR in C:\inetpub\wwwroot\ell\makeIdent.php on line 18
makeIdent.php:
require_once('dirpath.php');
if ( isset($_GET['GreekWord']) ) {
$curword = trim($_GET['GreekWord']);
$strRes = "";
if (strlen($curword) > 1) {
try {
$obj = new COM("Ellinognosia.ExtFunctions") or die("Unable to instantiate Ellinognosia");
$sid = 0;
$mdr = 0;
$output = $obj->fnInitialize("arxaia", $APPLICATIONDIRECTORY . "\\elllex", $DLLDIR, "utf8");
$output = $obj->fnIdentify($curword);
echo $output;
}
catch (Exception $e) {
$errmsg = $e->getMessage();
echo "Fatal error: " . $errmsg . " :internal error";
$logfile = fopen("error.log", "a");
if (flock($logfile, LOCK_EX)) {
fputs($logfile, date('d-m-Y') . " # " . date('H:i:s') . " # " . $_SERVER['REMOTE_ADDR'] . " # " . $_SERVER['HTTP_USER_AGENT'] . " # " . ($ref = (isset($_SERVER['HTTP_REFERER'])) ? $_SERVER['HTTP_REFERER'] : "NO_REFERER") . " # " . $_SERVER['REQUEST_URI'] . " # " . $errmsg . " # " . "Variables:\r\n" . print_r($_POST, true) . " # " . print_r($_GET, true) . "\r\n\r\n");
flock($logfile, LOCK_UN);
fclose($logfile);
}
}
} else {
echo "Fatal error: Parameters Length Incorrect :internal error";
}
} else {
echo "Fatal error: Missing Parameters :internal error";
}
?>
dirpath.php:
<?php
date_default_timezone_set("Europe/Athens");
$APPLICATIONDIRECTORY = "C:\\inetpub\\wwwroot\\ell";
if (strpos(php_uname("v"), " R2 ") > 0 || strpos(php_uname("v"), "ild 92") > 0) {
$DLLDIR = "C:\\Windows\\SysWOW64";
} else {
$DLLDIR = $APPLICATIONDIRECTORY . "\\elldll";
}
?>
example2:
[21-Apr-2018 07:36:27 Asia/Kuwait] PHP Fatal error: Call to undefined function toMonotonic() in C:\inetpub\wwwroot\ell\ajaxGetWordsFromLet.php on line 15
ajaxGetWordsFromLet.php:
<?php
require_once('phpcommonscripts/functions/fn_application.php');
try {
if ( isset($_GET['Letters']) && isset($_GET['CurLex']) ) {
$letters = trim($_GET['Letters']);
$curlex = trim($_GET['CurLex']);
if (mb_strlen($letters, "UTF-8") > 2 && mb_strlen($curlex, "UTF-8") > 0) {
$strReturn = "";
if ($curlex == "newg" || $curlex == "arch" || $curlex == "phrases") {
$letters = mb_substr($letters, 0, 32, "UTF-8");
$letters = toMonotonic($letters);
$letters = RemoveSimeiaStiksisArx($letters);
// more irrelevant php code here, the error is 2 lines above
}
echo $strReturn;
} else {
echo "Fatal error: Parameters Length Incorrect :internal error";
}
} else {
echo "Fatal error: Missing Parameters :internal error";
}
}
catch(Exception $e) {
$errmsg = $e->getMessage();
echo "Fatal error: " . $errmsg . " :internal error";
$logfile = fopen("error.log", "a");
if (flock($logfile, LOCK_EX)) {
fputs($logfile, date('d-m-Y') . " # " . date('H:i:s') . " # " . $_SERVER['REMOTE_ADDR'] . " # " . $_SERVER['HTTP_USER_AGENT'] . " # " . ($ref = (isset($_SERVER['HTTP_REFERER'])) ? $_SERVER['HTTP_REFERER'] : "NO_REFERER") . " # " . $_SERVER['REQUEST_URI'] . " # " . $errmsg . " # " . "Variables:\r\n" . print_r($_POST, true) . " # " . print_r($_GET, true) . "\r\n\r\n");
flock($logfile, LOCK_UN);
fclose($logfile);
}
}
?>
fn_application.php:
<?php
function toMonotonic($s) {
$s = str_replace(":α", "ά", $s);
$s = str_replace(":ε", "έ", $s);
$s = str_replace(":η", "ή", $s);
$s = str_replace(":ι", "ί", $s);
$s = str_replace(":ο", "ό", $s);
$s = str_replace(":υ", "ύ", $s);
$s = str_replace(":ω", "ώ", $s);
$s = str_replace(":ϊ", "ΐ", $s);
$s = str_replace(":ϋ", "ΰ", $s);
$s = str_replace(":Α", "Ά", $s);
$s = str_replace(":Ε", "Έ", $s);
$s = str_replace(":Η", "Ή", $s);
$s = str_replace(":Ι", "Ί", $s);
$s = str_replace(":Ο", "Ό", $s);
$s = str_replace(":Υ", "Ύ", $s);
$s = str_replace(":Ω", "Ώ", $s);
$s = str_replace(":Ϊ", "Ϊ", $s);
$s = str_replace(":Ϋ", "Ϋ", $s);
return $s;
}
// more functions here
?>
example3:
[21-Apr-2018 07:36:27 Asia/Kuwait] PHP Notice: Undefined variable: LGCACHEPDO in C:\inetpub\wwwroot\ell\displayOmor.php on line 38
[21-Apr-2018 07:36:27 Asia/Kuwait] PHP Fatal error: Call to undefined function getCache() in C:\inetpub\wwwroot\ell\displayOmor.php on line 39
displayOmor.php:
<?php
require_once('dirpath.php');
require_once("phpcommonscripts/connections/con_cache.php");
require_once("phpcommonscripts/functions/cache.php");
function get_data($url) {
$ch = curl_init();
$timeout = 100;
$userAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)";
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch,CURLOPT_USERAGENT, $userAgent);
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
function mb_ucfirst($str, $enc = 'utf-8') {
return mb_strtoupper(mb_substr($str, 0, 1, $enc), $enc).mb_substr($str, 1, mb_strlen($str, $enc), $enc);
}
if ( isset($_GET['GreekWord']) && isset($_GET['selectedRes']) ) {
$curword = trim($_GET['GreekWord']);
$selres = trim($_GET['selectedRes']);
$strRes = "";
if (strlen($curword) > 1 && strlen($selres) > 0) {
try {
$cacheoutput = "";
$useCache = true;
if ($LGCACHEPDO === null) $useCache = false;
$cacheoutput = getCache($useCache, $_SERVER['QUERY_STRING'], $_POST, pathinfo(__FILE__, PATHINFO_FILENAME));
if ($cacheoutput != "") {
$output = $cacheoutput;
} else {
//more code
}
$strRes = $output;
echo $strRes;
}
catch (Exception $e) {
$errmsg = $e->getMessage();
echo "Fatal error: " . $errmsg . " :internal error";
$logfile = fopen("error.log", "a");
if (flock($logfile, LOCK_EX)) {
fputs($logfile, date('d-m-Y') . " # " . date('H:i:s') . " # " . $_SERVER['REMOTE_ADDR'] . " # " . $_SERVER['HTTP_USER_AGENT'] . " # " . ($ref = (isset($_SERVER['HTTP_REFERER'])) ? $_SERVER['HTTP_REFERER'] : "NO_REFERER") . " # " . $_SERVER['REQUEST_URI'] . " # " . $errmsg . " # " . "Variables:\r\n" . print_r($_POST, true) . " # " . print_r($_GET, true) . "\r\n\r\n");
flock($logfile, LOCK_UN);
fclose($logfile);
}
}
} else {
echo "Fatal error: Parameters Length Incorrect :internal error";
}
} else {
echo "Fatal error: Missing Parameters :internal error";
}
?>
con_cache.php:
<?php
//Cache
$hostname_LGCACHE = "127.0.0.1";
$database_LGCACHE = "xxx";
$username_LGCACHE = "xxx";
$password_LGCACHE = "xxx";
$errorreporting = error_reporting();
try {
error_reporting(E_ALL ^ E_WARNING);
$LGCACHEPDO = new PDO("mysql:host=".$hostname_LGCACHE.";dbname=".$database_LGCACHE, $username_LGCACHE, $password_LGCACHE, array(PDO::ATTR_PERSISTENT => true, PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING, PDO::ATTR_TIMEOUT => 2));
} catch (PDOException $ex) {
$LGCACHEPDO = null;
}
error_reporting($errorreporting);
?>
cache.php:
<?php
$gl_TBLNAME = "";
$gl_QUERYSTRING = "";
function getCache($useCache, $serverQUERYSTRING, $serverPOST, $serverFILENAME) {
$ret = "";
if ($useCache === true) {
global $LGCACHEPDO;
global $gl_TBLNAME;
global $gl_QUERYSTRING;
$gl_QUERYSTRING = $serverQUERYSTRING;
if ($gl_QUERYSTRING == "") {
foreach ($serverPOST as $key => $value) $gl_QUERYSTRING = $gl_QUERYSTRING . $key . "=". urlencode($value) . "&";
$gl_QUERYSTRING = rtrim($gl_QUERYSTRING, "&");
}
$gl_TBLNAME = $serverFILENAME;
$getcache_PRST = $LGCACHEPDO->prepare("SELECT output FROM " . $gl_TBLNAME . " WHERE querystring = :querystring");
$getcache_PRST->bindValue(":querystring", $gl_QUERYSTRING);
$getcache_PRST->execute() or die($LGCACHEPDO->errorInfo());
if ($getcache_PRST->rowCount() == 1) {
$getcache_RSLT = $getcache_PRST->fetch(PDO::FETCH_ASSOC, PDO::FETCH_ORI_NEXT);
$ret = $getcache_RSLT["output"];
}
}
return $ret;
}
// more functions here
?>
What I understand is that for some reason PHP or Windows fails some times to load those files.
We have had this server box for ~4 years and only recently started to show these problems. This server handles 70% of the website load and runs a MYSQL server (the website load is ~80% of what it was a year ago, so no it hasn't gone up). There is a same hardware second machine which has Windows Server 2012 R2 64bit which handles 30% of the load and doesn't run any MYSQL server and never shows these kind of problems. Both servers have PHP 5.3.28
Any ideas and help on what to do to pinpoint the issue would be welcome. Thank you in advance.